Search Results

Search found 2457 results on 99 pages for 'implicit cast'.

Page 77/99 | < Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84  | Next Page >

  • Casting an object using 'as' returns null: myObject = newObject as MyObject; // null

    - by John Russell
    I am trying to create a custom object in AS3 to pass information to and from a server, which in this case will be Red5. In the below screenshots you will see that I am able to send a request for an object from as3, and receive it successfully from the java server. However, when I try to cast the received object to my defined objectType using 'as', it takes the value of null. It is my understanding that that when using "as" your checking to see if your variable is a member of the specified data type. If the variable is not, then null will be returned. This screenshot illustrates that I am have successfully received my object 'o' from red5 and I am just about to cast it to the (supposedly) identical datatype testObject of LobbyData: However, when testObject = o as LobbyData; runs, it returns null. :( Below you will see my specifications both on the java server and the as3 client. I am confident that both objects are identical in every way, but for some reason flash does not think so. I have been pulling my hair out for a long time, does anyone have any thoughts? AS3 Object: import flash.utils.IDataInput; import flash.utils.IDataOutput; import flash.utils.IExternalizable; import flash.net.registerClassAlias; [Bindable] [RemoteClass(alias = "myLobbyData.LobbyData")] public class LobbyData implements IExternalizable { private var sent:int; // java sentinel private var u:String; // red5 username private var sen:int; // another sentinel? private var ui:int; // fb uid private var fn:String; // fb name private var pic:String; // fb pic private var inb:Boolean; // is in the table? private var t:int; // table number private var s:int; // seat number public function setSent(sent:int):void { this.sent = sent; } public function getSent():int { return sent; } public function setU(u:String):void { this.u = u; } public function getU():String { return u; } public function setSen(sen:int):void { this.sen = sen; } public function getSen():int { return sen; } public function setUi(ui:int):void { this.ui = ui; } public function getUi():int { return ui; } public function setFn(fn:String):void { this.fn = fn; } public function getFn():String { return fn; } public function setPic(pic:String):void { this.pic = pic; } public function getPic():String { return pic; } public function setInb(inb:Boolean):void { this.inb = inb; } public function getInb():Boolean { return inb; } public function setT(t:int):void { this.t = t; } public function getT():int { return t; } public function setS(s:int):void { this.s = s; } public function getS():int { return s; } public function readExternal(input:IDataInput):void { sent = input.readInt(); u = input.readUTF(); sen = input.readInt(); ui = input.readInt(); fn = input.readUTF(); pic = input.readUTF(); inb = input.readBoolean(); t = input.readInt(); s = input.readInt(); } public function writeExternal(output:IDataOutput):void { output.writeInt(sent); output.writeUTF(u); output.writeInt(sen); output.writeInt(ui); output.writeUTF(fn); output.writeUTF(pic); output.writeBoolean(inb); output.writeInt(t); output.writeInt(s); } } Java Object: package myLobbyData; import org.red5.io.amf3.IDataInput; import org.red5.io.amf3.IDataOutput; import org.red5.io.amf3.IExternalizable; public class LobbyData implements IExternalizable { private static final long serialVersionUID = 115280920; private int sent; // java sentinel private String u; // red5 username private int sen; // another sentinel? private int ui; // fb uid private String fn; // fb name private String pic; // fb pic private Boolean inb; // is in the table? private int t; // table number private int s; // seat number public void setSent(int sent) { this.sent = sent; } public int getSent() { return sent; } public void setU(String u) { this.u = u; } public String getU() { return u; } public void setSen(int sen) { this.sen = sen; } public int getSen() { return sen; } public void setUi(int ui) { this.ui = ui; } public int getUi() { return ui; } public void setFn(String fn) { this.fn = fn; } public String getFn() { return fn; } public void setPic(String pic) { this.pic = pic; } public String getPic() { return pic; } public void setInb(Boolean inb) { this.inb = inb; } public Boolean getInb() { return inb; } public void setT(int t) { this.t = t; } public int getT() { return t; } public void setS(int s) { this.s = s; } public int getS() { return s; } @Override public void readExternal(IDataInput input) { sent = input.readInt(); u = input.readUTF(); sen = input.readInt(); ui = input.readInt(); fn = input.readUTF(); pic = input.readUTF(); inb = input.readBoolean(); t = input.readInt(); s = input.readInt(); } @Override public void writeExternal(IDataOutput output) { output.writeInt(sent); output.writeUTF(u); output.writeInt(sen); output.writeInt(ui); output.writeUTF(fn); output.writeUTF(pic); output.writeBoolean(inb); output.writeInt(t); output.writeInt(s); } } AS3 Client: public function refreshRoom(event:Event) { var resp:Responder=new Responder(handleResp,null); ncLobby.call("getLobbyData", resp, null); } public function handleResp(o:Object):void { var testObject:LobbyData=new LobbyData; testObject = o as LobbyData; trace(testObject); } Java Client public LobbyData getLobbyData(String param) { LobbyData lobbyData1 = new LobbyData(); lobbyData1.setSent(5); lobbyData1.setU("lawlcats"); lobbyData1.setSen(5); lobbyData1.setUi(5); lobbyData1.setFn("lulz"); lobbyData1.setPic("lulzagain"); lobbyData1.setInb(true); lobbyData1.setT(5); lobbyData1.setS(5); return lobbyData1; }

    Read the article

  • Erroneous/Incorrect C2248 error using Visual Studio 2010

    - by Dylan Bourque
    I'm seeing what I believe to be an erroneous/incorrect compiler error using the Visual Studio 2010 compiler. I'm in the process of up-porting our codebase from Visual Studio 2005 and I ran across a construct that was building correctly before but now generates a C2248 compiler error. Obviously, the code snippet below has been generic-ized, but it is a compilable example of the scenario. The ObjectPtr<T> C++ template comes from our codebase and is the source of the error in question. What appears to be happening is that the compiler is generating a call to the copy constructor for ObjectPtr<T> when it shouldn't (see my comment block in the SomeContainer::Foo() method below). For this code construct, there is a public cast operator for SomeUsefulData * on ObjectPtr<SomeUsefulData> but it is not being chosen inside the true expression if the ?: operator. Instead, I get the two errors in the block quote below. Based on my knowledge of C++, this code should compile. Has anyone else seen this behavior? If not, can someone point me to a clarification of the compiler resolution rules that would explain why it's attempting to generate a copy of the object in this case? Thanks in advance, Dylan Bourque Visual Studio build output: c:\projects\objectptrtest\objectptrtest.cpp(177): error C2248: 'ObjectPtr::ObjectPtr' : cannot access private member declared in class 'ObjectPtr' with [ T=SomeUsefulData ] c:\projects\objectptrtest\objectptrtest.cpp(25) : see declaration of 'ObjectPtr::ObjectPtr' with [ T=SomeUsefulData ] c:\projects\objectptrtest\objectptrtest.cpp(177): error C2248: 'ObjectPtr::ObjectPtr' : cannot access private member declared in class 'ObjectPtr' with [ T=SomeUsefulData ] c:\projects\objectptrtest\objectptrtest.cpp(25) : see declaration of 'ObjectPtr::ObjectPtr' with [ T=SomeUsefulData ] Below is a minimal, compilable example of the scenario: #include <stdio.h> #include <tchar.h> template<class T> class ObjectPtr { public: ObjectPtr<T> (T* pObj = NULL, bool bShared = false) : m_pObject(pObj), m_bObjectShared(bShared) {} ~ObjectPtr<T> () { Detach(); } private: // private, unimplemented copy constructor and assignment operator // to guarantee that ObjectPtr<T> objects are not copied ObjectPtr<T> (const ObjectPtr<T>&); ObjectPtr<T>& operator = (const ObjectPtr<T>&); public: T * GetObject () { return m_pObject; } const T * GetObject () const { return m_pObject; } bool HasObject () const { return (GetObject()!=NULL); } bool IsObjectShared () const { return m_bObjectShared; } void ObjectShared (bool bShared) { m_bObjectShared = bShared; } bool IsNull () const { return !HasObject(); } void Attach (T* pObj, bool bShared = false) { Detach(); if (pObj != NULL) { m_pObject = pObj; m_bObjectShared = bShared; } } void Detach (T** ppObject = NULL) { if (ppObject != NULL) { *ppObject = m_pObject; m_pObject = NULL; m_bObjectShared = false; } else { if (HasObject()) { if (!IsObjectShared()) delete m_pObject; m_pObject = NULL; m_bObjectShared = false; } } } void Detach (bool bDeleteIfNotShared) { if (HasObject()) { if (bDeleteIfNotShared && !IsObjectShared()) delete m_pObject; m_pObject = NULL; m_bObjectShared = false; } } bool IsEqualTo (const T * pOther) const { return (GetObject() == pOther); } public: T * operator -> () { ASSERT(HasObject()); return m_pObject; } const T * operator -> () const { ASSERT(HasObject()); return m_pObject; } T & operator * () { ASSERT(HasObject()); return *m_pObject; } const T & operator * () const { ASSERT(HasObject()); return (const C &)(*m_pObject); } operator T * () { return m_pObject; } operator const T * () const { return m_pObject; } operator bool() const { return (m_pObject!=NULL); } ObjectPtr<T>& operator = (T * pObj) { Attach(pObj, false); return *this; } bool operator == (const T * pOther) const { return IsEqualTo(pOther); } bool operator == (T * pOther) const { return IsEqualTo(pOther); } bool operator != (const T * pOther) const { return !IsEqualTo(pOther); } bool operator != (T * pOther) const { return !IsEqualTo(pOther); } bool operator == (const ObjectPtr<T>& other) const { return IsEqualTo(other.GetObject()); } bool operator != (const ObjectPtr<T>& other) const { return !IsEqualTo(other.GetObject()); } bool operator == (int pv) const { return (pv==NULL)? IsNull() : (LPVOID(m_pObject)==LPVOID(pv)); } bool operator != (int pv) const { return !(*this == pv); } private: T * m_pObject; bool m_bObjectShared; }; // Some concrete type that holds useful data class SomeUsefulData { public: SomeUsefulData () {} ~SomeUsefulData () {} }; // Some concrete type that holds a heap-allocated instance of // SomeUsefulData class SomeContainer { public: SomeContainer (SomeUsefulData* pUsefulData) { m_pData = pUsefulData; } ~SomeContainer () { // nothing to do here } public: bool EvaluateSomeCondition () { // fake condition check to give us an expression // to use in ?: operator below return true; } SomeUsefulData* Foo () { // this usage of the ?: operator generates a C2248 // error b/c it's attempting to call the copy // constructor on ObjectPtr<T> return EvaluateSomeCondition() ? m_pData : NULL; /**********[ DISCUSSION ]********** The following equivalent constructs compile w/out error and behave correctly: (1) explicit cast to SomeUsefulData* as a comiler hint return EvaluateSomeCondition() ? (SomeUsefulData *)m_pData : NULL; (2) if/else instead of ?: if (EvaluateSomeCondition()) return m_pData; else return NULL; (3) skip the condition check and return m_pData as a SomeUsefulData* directly return m_pData; **********[ END DISCUSSION ]**********/ } private: ObjectPtr<SomeUsefulData> m_pData; }; int _tmain(int argc, _TCHAR* argv[]) { return 0; }

    Read the article

  • SSRS Report from Oracle DB - Use stored procedure

    - by Emtucifor
    I am developing a report in Sql Server Reporting Services 2005, connecting to an Oracle 11g database. As you post replies perhaps it will help to know that I'm skilled in MSSQL Server and inexperienced in Oracle. I have multiple nested subreports and need to use summary data in outer reports and the same data but in detail in the inner reports. In order to spare the DB server from multiple executions, I thought to populate some temp tables at the beginning and then query just them the multiple times in the report and the subreports. In SSRS, Datasets are evidently executed in the order they appear in the RDL file. And you can have a dataset that doesn't return a rowset. So I created a stored procedure to populate my four temp tables and made this the first Dataset in my report. This SP works when I run it from SQLDeveloper and I can query the data from the temp tables. However, this didn't appear to work out because SSRS was apparently not reusing the same session, so even though the global temporary tables were created with ON COMMIT PRESERVE ROWS my Datasets were empty. I switched to using "real" tables and am now passing in an additional parameter, a GUID in string form, uniquely generated on each new execution, that is part of the primary key of each table, so I can get back just the rows for this execution. Running this from Sql Developer works fine, example: DECLARE ActivityCode varchar2(15) := '1208-0916 '; ExecutionID varchar2(32) := SYS_GUID(); BEGIN CIPProjectBudget (ActivityCode, ExecutionID); END; Never mind that in this example I don't know the GUID, this simply proves it works because rows are inserted to my four tables. But in the SSRS report, I'm still getting no rows in my Datasets and SQL Developer confirms no rows are being inserted. So I'm thinking along the lines of: Oracle uses implicit transactions and my changes aren't getting committed? Even though I can prove that the non-rowset returning SP is executing (because if I leave out the parameter mapping it complains at report rendering time about not having enough parameters) perhaps it's not really executing. Somehow. Wrong execution order isn't the problem or rows would appear in the tables, and they aren't. I'm interested in any ideas about how to accomplish this (especially the part about not running the main queries multiple times). I'll redesign my whole report. I'll stop using a stored procedure. Suggest anything you like! I just need help getting this working and I am stuck. If you want more details, in my SSRS report I have a List object (it's a container that repeats once for each row in a Dataset) that has some header values and then contains a subreport. Eventually, there will be four total reports: one main report, with three nested subreports. Each subreport will be in a List on the parent report.

    Read the article

  • Eventlet or gevent or Stackless + Twisted, Pylons, Django and SQL Alchemy

    - by Khorkrak
    We're using Twisted extensively for apps requiring a great deal of asynchronous io. There are some cases where stuff is cpu bound instead and for that we spawn a pool of processes to do the work and have a system for managing these across multiple servers as well - all done in Twisted. Works great. The problem is that it's hard to bring new team members up to speed. Writing asynchronous code in Twisted requires a near vertical learning curve. It's as if humans just don't think that way naturally. We're considering a mixed approach perhaps. Maybe do the xmlrpc server part and process management in Twisted still but the other stuff in code that at least looks synchronous while not being as such. Then again I like explicit over implicit so hmmm. Anyway onto greenlets - how well does that stuff work? So there's Stackless and as you can see from my Gallentean avatar I'm well aware of the tremendous success in it's use for CCP's flagship EVE Online game first hand. What about Eventlet or gevent? Well for now only Eventlet works with Twisted. However gevent claims to be faster since it's not a pure python implementation it instead uses libevent. It also has fewer idiosyncrasies and defects supposedly. The documentation there is minimal in comparison to Eventlet and it's maintained by 1 guy as far as I can tell. This makes me leery but all great projects start this way so... Then there's PyPy - I haven't even finished reading about that one yet - just saw it in this thread: Drawbacks of Stackless. So confusing - I'm wondering what the heck to do - sounds like Eventlet is probably the best bet but is it really stable enough? Anyone out there have any experience with it? Should we go with Stackless instead as it's been around and is proven technology - just like Twisted is as well - and they do work together nicely. But still I hate having to have a separate version of Python to do this. what to do.... This somewhat obnoxious blog entry hit the nail on the head for me though: Asynchronous IO for Grownups We're stuck using MySQL as well - I never knew how great PostgreSQL was until having had to work on a production OLTP system in MySQL instead - but that's another story. But if that monkey patch thing really works then wow. Just wow.

    Read the article

  • Geb not working with chrome driver

    - by user2346867
    @Grapes([ @Grab("org.gebish:geb-core:0.9.0"), @Grab("org.gebish:geb-spock:0.9.0"), @Grab("org.seleniumhq.selenium:selenium-firefox-driver:2.33.0"), @Grab("org.seleniumhq.selenium:selenium-chrome-driver:2.33.0"), @Grab("org.seleniumhq.selenium:selenium-support:2.26.0"), @Grab( group='org.spockframework', module='spock-core', version='0.3' ), @Grab(group='org.gebish', module='geb-implicit-assertions', version='0.9.0') ]) import geb.Browser import geb.spock.GebReportingSpec import org.openqa.selenium.chrome.* import spock.lang.Specification import geb.navigator.NonEmptyNavigator import geb.navigator.factory.* System.setProperty("webdriver.chrome.driver", "C:\\chromedriver\\chromedriver.exe"); def browser = new Browser(driver: new ChromeDriver()) browser.go "http://www.google.com/" assert browser.title == "Google" browser.$("input", name: "q").value("query") When i try to run the above code i am getting the following error WARNING: Sanitizing stacktrace: java.lang.NoClassDefFoundError: Could not initialize class geb.navigator.NonEmptyNavigator at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:171) at geb.navigator.factory.DefaultInnerNavigatorFactory.class$(DefaultInnerNavigatorFactory.groovy) at geb.navigator.factory.DefaultInnerNavigatorFactory.$get$$class$geb$navigator$NonEmptyNavigator(DefaultInnerNavigatorFactory.groovy) at geb.navigator.factory.DefaultInnerNavigatorFactory.createNavigator(DefaultInnerNavigatorFactory.groovy:40) at geb.navigator.factory.InnerNavigatorFactory$createNavigator.call(Unknown Source) at geb.navigator.factory.AbstractNavigatorFactory.createFromWebElements(AbstractNavigatorFactory.groovy:44) at geb.navigator.factory.NavigatorFactory$createFromWebElements.callCurrent(Unknown Source) at geb.navigator.factory.BrowserBackedNavigatorFactory.getBase(BrowserBackedNavigatorFactory.groovy:33) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233) at groovy.lang.MetaClassImpl.getProperty(MetaClassImpl.java:1671) at groovy.lang.MetaClassImpl.getProperty(MetaClassImpl.java:3408) at geb.navigator.factory.AbstractNavigatorFactory.getProperty(AbstractNavigatorFactory.groovy) at org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:47) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGetProperty(AbstractCallSite.java:227) at geb.content.NavigableSupport.getNavigator(NavigableSupport.groovy:39) at geb.content.NavigableSupport.$(NavigableSupport.groovy:96) at geb.content.NavigableSupport$$.call(Unknown Source) at geb.Page.$(Page.groovy) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1085) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:909) at org.codehaus.groovy.runtime.InvokerHelper.invokePogoMethod(InvokerHelper.java:848) at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:831) at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodN(ScriptBytecodeAdapter.java:164) at geb.Browser.methodMissing(Browser.groovy:193) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90) at groovy.lang.MetaClassImpl.invokeMissingMethod(MetaClassImpl.java:837) Any idea on this how to resolve it ???

    Read the article

  • Any significant performance improvement by using bitwise operators instead of plain int sums in C#?

    - by tunnuz
    Hello, I started working with C# a few weeks ago and I'm now in a situation where I need to build up a "bit set" flag to handle different cases in an algorithm. I have thus two options: enum RelativePositioning { LEFT = 0, RIGHT = 1, BOTTOM = 2, TOP = 3, FRONT = 4, BACK = 5 } pos = ((eye.X < minCorner.X ? 1 : 0) << RelativePositioning.LEFT) + ((eye.X > maxCorner.X ? 1 : 0) << RelativePositioning.RIGHT) + ((eye.Y < minCorner.Y ? 1 : 0) << RelativePositioning.BOTTOM) + ((eye.Y > maxCorner.Y ? 1 : 0) << RelativePositioning.TOP) + ((eye.Z < minCorner.Z ? 1 : 0) << RelativePositioning.FRONT) + ((eye.Z > maxCorner.Z ? 1 : 0) << RelativePositioning.BACK); Or: enum RelativePositioning { LEFT = 1, RIGHT = 2, BOTTOM = 4, TOP = 8, FRONT = 16, BACK = 32 } if (eye.X < minCorner.X) { pos += RelativePositioning.LEFT; } if (eye.X > maxCorner.X) { pos += RelativePositioning.RIGHT; } if (eye.Y < minCorner.Y) { pos += RelativePositioning.BOTTOM; } if (eye.Y > maxCorner.Y) { pos += RelativePositioning.TOP; } if (eye.Z > maxCorner.Z) { pos += RelativePositioning.FRONT; } if (eye.Z < minCorner.Z) { pos += RelativePositioning.BACK; } I could have used something as ((eye.X > maxCorner.X) << 1) but C# does not allow implicit casting from bool to int and the ternary operator was similar enough. My question now is: is there any performance improvement in using the first version over the second? Thank you Tommaso

    Read the article

  • Why default constructor does not appear for value types?

    - by Arun
    The below snippet gives me a list of constructors and methods of a type. static void ReflectOnType(Type type) { Console.WriteLine(type.FullName); Console.WriteLine("------------"); List<ConstructorInfo> constructors = type.GetConstructors(BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic |BindingFlags.Instance | BindingFlags.Default).ToList(); List<MethodInfo> methods = type.GetMethods().ToList(); Type baseType = type.BaseType; while (baseType != null) { constructors.AddRange(baseType.GetConstructors(BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Default)); methods.AddRange(baseType.GetMethods()); baseType = baseType.BaseType; } Console.WriteLine("Reflection on {0} type", type.Name); for (int i = 0; i < constructors.Count; i++) { Console.Write("Constructor: {0}.{1}", constructors[i].DeclaringType.Name, constructors[i].Name); Console.Write("("); ParameterInfo[] parameterInfos = constructors[i].GetParameters(); if (parameterInfos.Length > 0) { for (int j = 0; j < parameterInfos.Length; j++) { if (j > 0) { Console.Write(", "); } Console.Write("{0} {1}", parameterInfos[j].ParameterType, parameterInfos[j].Name); } } Console.Write(")"); if (constructors[i].IsSpecialName) { Console.Write(" has 'SpecialName' attribute"); } Console.WriteLine(); } Console.WriteLine(); for (int i = 0; i < methods.Count; i++) { Console.Write("Method: {0}.{1}", methods[i].DeclaringType.Name, methods[i].Name); // Determine whether or not each field is a special name. if (methods[i].IsSpecialName) { Console.Write(" has 'SpecialName' attribute"); } Console.WriteLine(); } } But when I pass an ‘int’ type to this method, why don’t I see the implicit constructor in the output? Or, how do I modify the above code to list the default constructor as well (in case I’m missing something in my code).

    Read the article

  • ASP.NET MVC 2 actionlink breaking after migration from MVC version 1

    - by thermal7
    Hi, I am migrating my application from asp.net mvc to mvc version 2 and am having the following issue. I have paging links << < that I include in each page. Like so: <% Html.RenderPartial("PagingControl", Model); %> They exist in an ascx file as follows. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<BankingDB.Controllers.Utility.IPagedSortedObject>" %> <div class="paging"> <div class="previous-paging"> <!- error!! -><%= Model.HasPreviousPage ? Html.ActionLink("<<", "Index", Model.buildParams(1)) : "<<"%> <%= Model.HasPreviousPage ? Html.ActionLink("<", "Index", Model.buildParams(Model.PreviousPageIndex)) : "<"%> </div> <div class="paging-details"> Showing records <%= Model.BaseRecordIndex %> to <%= Model.MaxRecordIndex %> of <%= Model.TotalRecordCount %> </div> <div class="next-paging"> <%= Model.HasNextPage ? Html.ActionLink(">", "Index", Model.buildParams(Model.NextPageIndex)) : ">"%> <%= Model.HasNextPage ? Html.ActionLink(">>", "Index", Model.buildParams(Model.PageCount)) : ">>"%> </div> </div> When I try to access the page I get the error: CS0173: Type of conditional expression cannot be determined because there is no implicit conversion between 'System.Web.Mvc.MvcHtmlString' and 'string' The error is marked above and appears to be with the action link. Including the controller name doesn't help. Any ideas?

    Read the article

  • Scared of Calculus - Required to pass Differential Calculus as part of my Computer science major

    - by ke3pup
    Hi guys I'm finishing my Computer science degree in university but my fear of maths (lack of background knowledge) made me to leave all my maths units til' the very end which is now. i either take them on and pass or have to give up. I've passed all my programming units easily but knowing my poor maths skills won't do i've been staying clear of the maths units. I have to pass Differential Calculus and Linear Algebra first. With a help of book named "Linear Algebra: A Modern Introduction" i'm finding myself on track and i think i can pass the Linear Algebra unit. But with differential calculus i can't find a book to help me. They're either too advanced or just too simple for what i have to learn. The things i'm required to know for this units are: Set notation, the real number line, Complex numbers in cartesian form. Complex plane, modulus. Complex numbers in polar form. De Moivre’s Theorem. Complex powers and nth roots. Definition of ei? and ez for z complex. Applications to trigonometry. Revision of domain and range of a function Working in R3. Curves and surfaces. Functions of 2 variables. Level curves.Partial derivatives and tangent planes. The derivative as a difference quotient. Geometric significance of the derivative. Discussion of limit. Higher order partial derivatives. Limits of f(x,y). Continuity. Maxima and minima of f(x,y). The chain rule. Implicit differentiation. Directional derivatives and the gradient. Limit laws, l’Hoˆpital’s rule, composition law. Definition of sinh and cosh and their inverses. Taylor polynomials. The remainder term. Taylor series. Is there a book to help me get on track with the above? Being a student i can't buy too many books hence why i'm looking for a book that covers topics I need to know. The University library has a fairly limited collection which i took as loan but didn't find useful as it was too complex.

    Read the article

  • Is the Scala 2.8 collections library a case of "the longest suicide note in history" ?

    - by oxbow_lakes
    First note the inflammatory subject title is a quotation made about the manifesto of a UK political party in the early 1980s. This question is subjective but it is a genuine question, I've made it CW and I'd like some opinions on the matter. Despite whatever my wife and coworkers keep telling me, I don't think I'm an idiot: I have a good degree in mathematics from the University of Oxford and I've been programming commercially for almost 12 years and in Scala for about a year (also commercially). I have just started to look at the Scala collections library re-implementation which is coming in the imminent 2.8 release. Those familiar with the library from 2.7 will notice that the library, from a usage perspective, has changed little. For example... > List("Paris", "London").map(_.length) res0: List[Int] List(5, 6) ...would work in either versions. The library is eminently useable: in fact it's fantastic. However, those previously unfamiliar with Scala and poking around to get a feel for the language now have to make sense of method signatures like: def map[B, That](f: A => B)(implicit bf: CanBuildFrom[Repr, B, That]): That For such simple functionality, this is a daunting signature and one which I find myself struggling to understand. Not that I think Scala was ever likely to be the next Java (or /C/C++/C#) - I don't believe its creators were aiming it at that market - but I think it is/was certainly feasible for Scala to become the next Ruby or Python (i.e. to gain a significant commercial user-base) Is this going to put people off coming to Scala? Is this going to give Scala a bad name in the commercial world as an academic plaything that only dedicated PhD students can understand? Are CTOs and heads of software going to get scared off? Was the library re-design a sensible idea? If you're using Scala commercially, are you worried about this? Are you planning to adopt 2.8 immediately or wait to see what happens? Steve Yegge once attacked Scala (mistakenly in my opinion) for what he saw as its overcomplicated type-system. I worry that someone is going to have a field day spreading fud with this API (similarly to how Josh Bloch scared the JCP out of adding closures to Java). Note - I should be clear that, whilst I believe that Josh Bloch was influential in the rejection of the BGGA closures proposal, I don't ascribe this to anything other than his honestly-held beliefs that the proposal represented a mistake.

    Read the article

  • Parse int to string with stringstream

    - by SoulBeaver
    Well! I feel really stupid for this question, and I wholly don't mind if I get downvoted for this, but I guess I wouldn't be posting this if I had not at least made an earnest attempt at looking for the solution. I'm currently working on Euler Problem 4, finding the largest palindromic number of two three-digit numbers [100..999]. As you might guess, I'm at the part where I have to work with the integer I made. I looked up a few sites and saw a few standards for converting an Int to a String, one of which included stringstream. So my code looked like this: // tempTotal is my int value I want converted. void toString( int tempTotal, string &str ) { ostringstream ss; // C++ Standard compliant method. ss << tempTotal; str = ss.str(); // Overwrite referenced value of given string. } and the function calling it was: else { toString( tempTotal, store ); cout << loop1 << " x " << loop2 << "= " << store << endl; } So far, so good. I can't really see an error in what I've written, but the output gives me the address to something. It stays constant, so I don't really know what the program is doing there. Secondly, I tried .ToString(), string.valueOf( tempTotal ), (string)tempTotal, or simply store = temptotal. All refused to work. When I simply tried doing an implicit cast with store = tempTotal, it didn't give me a value at all. When I tried checking output it literally printed nothing. I don't know if anything was copied into my string that simply isn't a printable character, or if the compiler just ignored it. I really don't know. So even though I feel this is a really, really lame question, I just have to ask: How do I convert that stupid integer to a string with the stringstream? The other tries are more or less irrelevant for me, I just really want to know why my stringstream solution isn't working.

    Read the article

  • Can anyone explain me the source code of python "import this"?

    - by byterussian
    If you open a Python interpreter, and type "import this", as you know, it prints: The Zen of Python, by Tim Peters Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. Flat is better than nested. Sparse is better than dense. Readability counts. Special cases aren't special enough to break the rules. Although practicality beats purity. Errors should never pass silently. Unless explicitly silenced. In the face of ambiguity, refuse the temptation to guess. There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than *right* now. If the implementation is hard to explain, it's a bad idea. If the implementation is easy to explain, it may be a good idea. Namespaces are one honking great idea -- let's do more of those! In the python source(Lib/this.py) this text is generated by a curios piece of code: s = """Gur Mra bs Clguba, ol Gvz Crgref Ornhgvshy vf orggre guna htyl. Rkcyvpvg vf orggre guna vzcyvpvg. Fvzcyr vf orggre guna pbzcyrk. Pbzcyrk vf orggre guna pbzcyvpngrq. Syng vf orggre guna arfgrq. Fcnefr vf orggre guna qrafr. Ernqnovyvgl pbhagf. Fcrpvny pnfrf nera'g fcrpvny rabhtu gb oernx gur ehyrf. Nygubhtu cenpgvpnyvgl orngf chevgl. Reebef fubhyq arire cnff fvyragyl. Hayrff rkcyvpvgyl fvyraprq. Va gur snpr bs nzovthvgl, ershfr gur grzcgngvba gb thrff. Gurer fubhyq or bar-- naq cersrenoyl bayl bar --boivbhf jnl gb qb vg. Nygubhtu gung jnl znl abg or boivbhf ng svefg hayrff lbh'er Qhgpu. Abj vf orggre guna arire. Nygubhtu arire vf bsgra orggre guna *evtug* abj. Vs gur vzcyrzragngvba vf uneq gb rkcynva, vg'f n onq vqrn. Vs gur vzcyrzragngvba vf rnfl gb rkcynva, vg znl or n tbbq vqrn. Anzrfcnprf ner bar ubaxvat terng vqrn -- yrg'f qb zber bs gubfr!""" d = {} for c in (65, 97): for i in range(26): d[chr(i+c)] = chr((i+13) % 26 + c) print "".join([d.get(c, c) for c in s])

    Read the article

  • Cannot figure out how to take in generic parameters for an Enterprise Framework library sql statemen

    - by KallDrexx
    I have written a specialized class to wrap up the enterprise library database functionality for easier usage. The reasoning for using the Enterprise Library is because my applications commonly connect to both oracle and sql server database systems. My wrapper handles both creating connection strings on the fly, connecting, and executing queries allowing my main code to only have to write a few lines of code to do database stuff and deal with error handling. As an example my ExecuteNonQuery method has the following declaration: /// <summary> /// Executes a query that returns no results (e.g. insert or update statements) /// </summary> /// <param name="sqlQuery"></param> /// <param name="parameters">Hashtable containing all the parameters for the query</param> /// <returns>The total number of records modified, -1 if an error occurred </returns> public int ExecuteNonQuery(string sqlQuery, Hashtable parameters) { // Make sure we are connected to the database if (!IsConnected) { ErrorHandler("Attempted to run a query without being connected to a database.", ErrorSeverity.Critical); return -1; } // Form the command DbCommand dbCommand = _database.GetSqlStringCommand(sqlQuery); // Add all the paramters foreach (string key in parameters.Keys) { if (parameters[key] == null) _database.AddInParameter(dbCommand, key, DbType.Object, null); else _database.AddInParameter(dbCommand, key, DbType.Object, parameters[key].ToString()); } return _database.ExecuteNonQuery(dbCommand); } _database is defined as private Database _database;. Hashtable parameters are created via code similar to p.Add("@param", value);. the issue I am having is that it seems that with enterprise library database framework you must declare the dbType of each parameter. This isn't an issue when you are calling the database code directly when forming the paramters but doesn't work for creating a generic abstraction class such as I have. In order to try and get around that I thought I could just use DbType.Object and figure the DB will figure it out based on the columns the sql is working with. Unfortunately, this is not the case as I get the following error: Implicit conversion from data type sql_variant to varchar is not allowed. Use the CONVERT function to run this query Is there any way to use generic parameters in a wrapper class or am I just going to have to move all my DB code into my main classes?

    Read the article

  • Go - Using a container/heap to implement a priority queue

    - by Seth Hoenig
    In the big picture, I'm trying to implement Dijkstra's algorithm using a priority queue. According to members of golang-nuts, the idiomatic way to do this in Go is to use the heap interface with a custom underlying data structure. So I have created Node.go and PQueue.go like so: //Node.go package pqueue type Node struct { row int col int myVal int sumVal int } func (n *Node) Init(r, c, mv, sv int) { n.row = r n.col = c n.myVal = mv n.sumVal = sv } func (n *Node) Equals(o *Node) bool { return n.row == o.row && n.col == o.col } And PQueue.go: // PQueue.go package pqueue import "container/vector" import "container/heap" type PQueue struct { data vector.Vector size int } func (pq *PQueue) Init() { heap.Init(pq) } func (pq *PQueue) IsEmpty() bool { return pq.size == 0 } func (pq *PQueue) Push(i interface{}) { heap.Push(pq, i) pq.size++ } func (pq *PQueue) Pop() interface{} { pq.size-- return heap.Pop(pq) } func (pq *PQueue) Len() int { return pq.size } func (pq *PQueue) Less(i, j int) bool { I := pq.data.At(i).(Node) J := pq.data.At(j).(Node) return (I.sumVal + I.myVal) < (J.sumVal + J.myVal) } func (pq *PQueue) Swap(i, j int) { temp := pq.data.At(i).(Node) pq.data.Set(i, pq.data.At(j).(Node)) pq.data.Set(j, temp) } And main.go: (the action is in SolveMatrix) // Euler 81 package main import "fmt" import "io/ioutil" import "strings" import "strconv" import "./pqueue" const MATSIZE = 5 const MATNAME = "matrix_small.txt" func main() { var matrix [MATSIZE][MATSIZE]int contents, err := ioutil.ReadFile(MATNAME) if err != nil { panic("FILE IO ERROR!") } inFileStr := string(contents) byrows := strings.Split(inFileStr, "\n", -1) for row := 0; row < MATSIZE; row++ { byrows[row] = (byrows[row])[0 : len(byrows[row])-1] bycols := strings.Split(byrows[row], ",", -1) for col := 0; col < MATSIZE; col++ { matrix[row][col], _ = strconv.Atoi(bycols[col]) } } PrintMatrix(matrix) sum, len := SolveMatrix(matrix) fmt.Printf("len: %d, sum: %d\n", len, sum) } func PrintMatrix(mat [MATSIZE][MATSIZE]int) { for r := 0; r < MATSIZE; r++ { for c := 0; c < MATSIZE; c++ { fmt.Printf("%d ", mat[r][c]) } fmt.Print("\n") } } func SolveMatrix(mat [MATSIZE][MATSIZE]int) (int, int) { var PQ pqueue.PQueue var firstNode pqueue.Node var endNode pqueue.Node msm1 := MATSIZE - 1 firstNode.Init(0, 0, mat[0][0], 0) endNode.Init(msm1, msm1, mat[msm1][msm1], 0) if PQ.IsEmpty() { // make compiler stfu about unused variable fmt.Print("empty") } PQ.Push(firstNode) // problem return 0, 0 } The problem is, upon compiling i get the error message: [~/Code/Euler/81] $ make 6g -o pqueue.6 Node.go PQueue.go 6g main.go main.go:58: implicit assignment of unexported field 'row' of pqueue.Node in function argument make: *** [all] Error 1 And commenting out the line PQ.Push(firstNode) does satisfy the compiler. But I don't understand why I'm getting the error message in the first place. Push doesn't modify the argument in any way.

    Read the article

  • .NET: Is there a way to finagle a default namespace in an XPath 1.0 query?

    - by Cheeso
    I'm building a tool that performs xpath 1.0 queries on XHTML documents. The requirement to use a namespace prefix in the query is killing me. The query looks like this: html/body/div[@class='contents']/div[@class='body']/ div[@class='pgdbbyauthor']/h2[a[@name][starts-with(.,'Quick')]]/ following-sibling::ul[1]/li/a (all on one line) ...which is bad enough, except because it's xpath 1.0, I need to use an explicit namespace prefix on each QName, so it looks like this: ns1:html/ns1:body/ns1:div[@class='contents']/ns1:div[@class='body']/ ns1:div[@class='pgdbbyauthor']/ns1:h2[ns1:a[@name][starts-with(.,'Quick')]]/ following-sibling::ns1:ul[1]/ns1:li/ns1:a To set up the query, I do something like this: var xpathDoc = new XPathDocument(new StringReader(theText)); var nav = xpathDoc.CreateNavigator(); var xmlns = new XmlNamespaceManager(nav.NameTable); foreach (string prefix in xmlNamespaces.Keys) xmlns.AddNamespace(prefix, xmlNamespaces[prefix]); XPathNodeIterator selection = nav.Select(xpathExpression, xmlns); But what I want is for the xpathExpression to use the implicit default namespace. Is there a way for me to transform the unadorned xpath expression, after it's been written, to inject a namespace prefix for each element name in the query? I'm thinking, anything between two slashes, I could inject a prefix there. Excepting of course axis names like "parent::" and "preceding-sibling::" . And wildcards. That's what I mean by "finagle a default namespace". Is this hack gonna work? Addendum Here's what I mean. suppose I have an xpath expression, and before passing it to nav.Select(), I transform it. Something like this: string FixupWithDefaultNamespace(string expr) { string s = expr; s = Regex.Replace(s, "^(?!::)([^/:]+)(?=/)", "ns1:$1"); // beginning s = Regex.Replace(s, "/([^/:]+)(?=/)", "/ns1:$1"); // stanza s = Regex.Replace(s, "::([A-Za-z][^/:*]*)(?=/)", "::ns1:$1"); // axis specifier s = Regex.Replace(s, "\\[([A-Za-z][^/:*\\(]*)(?=[\\[\\]])", "[ns1:$1"); // predicate s = Regex.Replace(s, "/([A-Za-z][^/:]*)(?!<::)$", "/ns1:$1"); // end s = Regex.Replace(s, "^([A-Za-z][^/:]*)$", "ns1:$1"); // edge case s = Regex.Replace(s, "([-A-Za-z]+)\\(([^/:\\.,\\)]+)(?=[,\\)])", "$1(ns1:$2"); // xpath functions return s; } This actually works for simple cases I tried. To use the example from above - if the input is the first xpath expression, the output I get is the 2nd one, with all the ns1 prefixes. The real question is, is it hopeless to expect this Regex.Replace approach to work, as the xpath expressions get more complicated?

    Read the article

  • Android HelloGoogleMaps to OSMdroid (Open Street Maps)

    - by birgit
    I am trying to reproduce a working HelloGoogleMaps app in Open Street Maps - but I have trouble including the itemized overlay in OSMdroid. I have looked at several resources but I cannot figure out how to fix the error on OsmItemizedOverlay - I guess I am constructing OsmItemizedOverlay wrongly or have a mixup with OsmItemizedOverlay and ItemizedOverlay? But everything I tried to change just raised more errors... "Implicit super constructor ItemizedOverlay() is undefined. Must explicitly invoke another constructor" "Cannot make a static reference to the non-static method setMarker(Drawable) from the type OverlayItem" - I hope someone can help me getting the class definition straight? Thanks so much! package com.example.osmdroiddemomap; import java.util.ArrayList; import android.app.AlertDialog; import android.content.Context; import android.graphics.Point; import android.graphics.drawable.Drawable; import org.osmdroid.api.IMapView; import org.osmdroid.views.*; import org.osmdroid.views.overlay.*; import org.osmdroid.views.overlay.OverlayItem.HotspotPlace; public class OsmItemizedOverlay extends ItemizedOverlay<OverlayItem> { Context mContext; private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>(); //ERRORS are raised by the following 3 lines: public OsmItemizedOverlay(Drawable defaultMarker, Context context) { OverlayItem.setMarker(defaultMarker); OverlayItem.setMarkerHotspot(HotspotPlace.CENTER); mContext = context; } public void addOverlay(OverlayItem overlay) { mOverlays.add(overlay); populate(); } @Override protected OverlayItem createItem(int i) { return mOverlays.get(i); } @Override public int size() { return mOverlays.size(); } protected boolean onTap(int index) { OverlayItem item = mOverlays.get(index); AlertDialog.Builder dialog = new AlertDialog.Builder(mContext); dialog.setTitle(item.getTitle()); dialog.setMessage(item.getSnippet()); dialog.show(); return true; } @Override public boolean onSnapToItem(int arg0, int arg1, Point arg2, IMapView arg3) { // TODO Auto-generated method stub return false; } }

    Read the article

  • C# Property Access vs Interface Implementation

    - by ehdv
    I'm writing a class to represent a Pivot Collection, the root object recognized by Pivot. A Collection has several attributes, a list of facet categories (each represented by a FacetCategory object) and a list of items (each represented by a PivotItem object). Therefore, an extremely simplified Collection reads: public class Collection { private List<FacetCategory> categories; private List<PivotItem> items; // other attributes } What I'm unsure of is how to properly grant access to those two lists. Because declaration order of both facet categories and items is visible to the user, I can't use sets, but the class also shouldn't allow duplicate categories or items. Furthermore, I'd like to make the Collection object as easy to use as possible. So my choices are: Have Collection implement IList<PivotItem> and have accessor methods for FacetCategory: In this case, one would add an item to Collection foo by writing foo.Add(bar). This works, but since a Collection is equally both kinds of list making it only pass as a list for one type (category or item) seems like a subpar solution. Create nested wrapper classes for List (CategoryList and ItemList). This has the advantage of making a consistent interface but the downside is that these properties would no longer be able to serve as lists (because I need to override the non-virtual Add method I have to implement IList rather than subclass List. Implicit casting wouldn't work because that would return the Add method to its normal behavior. Also, for reasons I can't figure out, IList is missing an AddRange method... public class Collection { private class CategoryList: IList<FacetCategory> { // ... } private readonly CategoryList categories = new CategoryList(); private readonly ItemList items = new ItemList(); public CategoryList FacetCategories { get { return categories; } set { categories.Clear(); categories.AddRange(value); } } public ItemList Items { get { return items; } set { items.Clear(); items.AddRange(value); } } } Finally, the third option is to combine options one and two, so that Collection implements IList<PivotItem> and has a property FacetCategories. Question: Which of these three is most appropriate, and why?

    Read the article

  • Class template specializations with shared functionality

    - by Thomas
    I'm writing a simple maths library with a template vector type: template<typename T, size_t N> class Vector { public: Vector<T, N> &operator+=(Vector<T, N> const &other); // ... more operators, functions ... }; Now I want some additional functionality specifically for some of these. Let's say I want functions x() and y() on Vector<T, 2> to access particular coordinates. I could create a partial specialization for this: template<typename T> class Vector<T, 3> { public: Vector<T, 3> &operator+=(Vector<T, 3> const &other); // ... and again all the operators and functions ... T x() const; T y() const; }; But now I'm repeating everything that already existed in the generic template. I could also use inheritance. Renaming the generic template to VectorBase, I could do this: template<typename T, size_t N> class Vector : public VectorBase<T, N> { }; template<typename T> class Vector<T, 3> : public VectorBase<T, 3> { public: T x() const; T y() const; }; However, now the problem is that all operators are defined on VectorBase, so they return VectorBase instances. These cannot be assigned to Vector variables: Vector<float, 3> v; Vector<float, 3> w; w = 5 * v; // error: no conversion from VectorBase<float, 3> to Vector<float, 3> I could give Vector an implicit conversion constructor to make this possible: template<typename T, size_t N> class Vector : public VectorBase<T, N> { public: Vector(VectorBase<T, N> const &other); }; However, now I'm converting from Vector to VectorBase and back again. Even though the types are the same in memory, and the compiler might optimize all this away, it feels clunky and I don't really like to have potential run-time overhead for what is essentially a compile-time problem. Is there any other way to solve this?

    Read the article

  • C++ addition overload ambiguity

    - by Nate
    I am coming up against a vexing conundrum in my code base. I can't quite tell why my code generates this error, but (for example) std::string does not. class String { public: String(const char*str); friend String operator+ ( const String& lval, const char *rval ); friend String operator+ ( const char *lval, const String& rval ); String operator+ ( const String& rval ); }; The implementation of these is easy enough to imagine on your own. My driver program contains the following: String result, lval("left side "), rval("of string"); char lv[] = "right side ", rv[] = "of string"; result = lv + rval; printf(result); result = (lval + rv); printf(result); Which generates the following error in gcc 4.1.2: driver.cpp:25: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second: String.h:22: note: candidate 1: String operator+(const String&, const char*) String.h:24: note: candidate 2: String String::operator+(const String&) So far so good, right? Sadly, my String(const char *str) constructor is so handy to have as an implicit constructor, that using the explicit keyword to solve this would just cause a different pile of problems. Moreover... std::string doesn't have to resort to this, and I can't figure out why. For example, in basic_string.h, they are declared as follows: template<typename _CharT, typename _Traits, typename _Alloc> basic_string<_CharT, _Traits, _Alloc> operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs) template<typename _CharT, typename _Traits, typename _Alloc> basic_string<_CharT,_Traits,_Alloc> operator+(const _CharT* __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs); and so on. The basic_string constructor is not declared explicit. How does this not cause the same error I'm getting, and how can I achieve the same behavior??

    Read the article

  • C#/.NET Project - Am I setting things up correctly?

    - by JustLooking
    1st solution located: \Common\Controls\Controls.sln and its project: \Common\Controls\Common.Controls\Common.Controls.csproj Description: This is a library that contains this class: public abstract class OurUserControl : UserControl { // Variables and other getters/setters common to our UserControls } 2nd solution located: \AControl\AControl.sln and its project: \AControl\AControl\AControl.csproj Description: Of the many forms/classes, it will contain this class: using Common.Controls; namespace AControl { public partial class AControl : OurUserControl { // The implementation } } A note about adding references (not sure if this is relevant): When I add references (for projects I create), using the names above: 1. I add Common.Controls.csproj to AControl.sln 2. In AControl.sln I turn off the build of Common.Controls.csproj 3. I add the reference to Common.Controls (by project) to AControl.csproj. This is the (easiest) way I know how to get Debug versions to match Debug References, and Release versions to match Release References. Now, here is where the issue lies (the 3rd solution/project that actually utilizes the UserControl): 3rd solution located: \MainProj\MainProj.sln and its project: \MainProj\MainProj\MainProj.csproj Description: Here's a sample function in one of the classes: private void TestMethod<T>() where T : Common.Controls.OurUserControl, new() { T TheObject = new T(); TheObject.OneOfTheSetters = something; TheObject.AnotherOfTheSetters = something_else; // Do stuff with the object } We might call this function like so: private void AnotherMethod() { TestMethod<AControl.AControl>(); } This builds, runs, and works. No problem. The odd thing is after I close the project/solution and re-open it, I have red squigglies everywhere. I bring up my error list and I see tons of errors (anything that deals with AControl will be noted as an error). I'll see errors such as: The type 'AControl.AControl' cannot be used as type parameter 'T' in the generic type or method 'MainProj.MainClass.TestMethod()'. There is no implicit reference conversion from 'AControl.AControl' to 'Common.Controls.OurUserControl'. or inside the actual method (the properties located in the abstract class): 'AControl.AControl' does not contain a definition for 'OneOfTheSetters' and no extension method 'OneOfTheSetters' accepting a first argument of type 'AControl.AControl' could be found (are you missing a using directive or an assembly reference?) Meanwhile, I can still build and run the project (then the red squigglies go away until I re-open the project, or close/re-open the file). It seems to me that I might be setting up the projects incorrectly. Thoughts?

    Read the article

  • What to Expect in Rails 4

    - by mikhailov
    Rails 4 is nearly there, we should be ready before it released. Most developers are trying hard to keep their application on the edge. Must see resources: 1) @sikachu talk: What to Expect in Rails 4.0 - YouTube 2) Rails Guides release notes: http://edgeguides.rubyonrails.org/4_0_release_notes.html There is a mix of all major changes down here: ActionMailer changes excerpt: Asynchronously send messages via the Rails Raise an ActionView::MissingTemplate exception when no implicit template could be found ActionPack changes excerpt Added controller-level etag additions that will be part of the action etag computation Add automatic template digests to all CacheHelper#cache calls (originally spiked in the cache_digests plugin) Add Routing Concerns to declare common routes that can be reused inside others resources and routes Added ActionController::Live. Mix it in to your controller and you can stream data to the client live truncate now always returns an escaped HTML-safe string. The option :escape can be used as false to not escape the result Added ActionDispatch::SSL middleware that when included force all the requests to be under HTTPS protocol ActiveModel changes excerpt AM::Validation#validates ability to pass custom exception to :strict option Changed `AM::Serializers::JSON.include_root_in_json' default value to false. Now, AM Serializers and AR objects have the same default behaviour Added ActiveModel::Model, a mixin to make Ruby objects work with AP out of box Trim down Active Model API by removing valid? and errors.full_messages ActiveRecord changes excerpt Use native mysqldump command instead of structure_dump method when dumping the database structure to a sql file. Attribute predicate methods, such as article.title?, will now raise ActiveModel::MissingAttributeError if the attribute being queried for truthiness was not read from the database, instead of just returning false ActiveRecord::SessionStore has been extracted from Active Record as activerecord-session_store gem. Please read the README.md file on the gem for the usage Fix reset_counters when there are multiple belongs_to association with the same foreign key and one of them have a counter cache Raise ArgumentError if list of attributes to change is empty in update_all Add Relation#load. This method explicitly loads the records and then returns self Deprecated most of the 'dynamic finder' methods. All dynamic methods except for find_by_... and find_by_...! are deprecated Added ability to ActiveRecord::Relation#from to accept other ActiveRecord::Relation objects Remove IdentityMap ActiveSupport changes excerpt ERB::Util.html_escape now escapes single quotes ActiveSupport::Callbacks: deprecate monkey patch of object callbacks Replace deprecated memcache-client gem with dalli in ActiveSupport::Cache::MemCacheStore Object#try will now return nil instead of raise a NoMethodError if the receiving object does not implement the method, but you can still get the old behavior by using the new Object#try! Object#try can't call private methods Add ActiveSupport::Deprecations.behavior = :silence to completely ignore Rails runtime deprecations What are the most important changes for you?

    Read the article

  • Why are static classes considered “classes” and “reference types”?

    - by Timwi
    I’ve been pondering about the C# and CIL type system today and I’ve started to wonder why static classes are considered classes. There are many ways in which they are not really classes: A “normal” class can contain non-static members, a static class can’t. In this respect, a class is more similar to a struct than it is to a static class, and yet structs have a separate name. You can have a reference to an instance of a “normal” class, but not a static class (despite it being considered a “reference type”). In this respect, a class is more similar to an interface than it is to a static class, and yet interfaces have a separate name. The name of a static class can never be used in any place where a type name would normally fit: you can’t declare a variable of this type, you can’t use it as a base type, and you can’t use it as a generic type parameter. In this respect, static classes are somewhat more like namespaces. A “normal” class can implement interfaces. Once again, that makes classes more similar to structs than to static classes. A “normal” class can inherit from another class. It is also bizarre that static classes are considered to derive from System.Object. Although this allows them to “inherit” the static methods Equals and ReferenceEquals, the purpose of that inheritance is questionable as you would call those methods on object anyway. C# even allows you to specify that useless inheritance explicitly on static classes, but not on interfaces or structs, where the implicit derivation from object and System.ValueType, respectively, actually has a purpose. Regarding the subset-of-features argument: Static classes have a subset of the features of classes, but they also have a subset of the features of structs. All of the things that make a class distinct from the other kinds of type, do not seem to apply to static classes. Regarding the typeof argument: Making a static class into a new and different kind of type does not preclude it from being used in typeof. Given the sheer oddity of static classes, and the scarcity of similarities between them and “normal” classes, shouldn’t they have been made into a separate kind of type instead of a special kind of class?

    Read the article

  • Marshalling non-Blittable Structs from C# to C++

    - by Greggo
    I'm in the process of rewriting an overengineered and unmaintainable chunk of my company's library code that interfaces between C# and C++. I've started looking into P/Invoke, but it seems like there's not much in the way of accessible help. We're passing a struct that contains various parameters and settings down to unmanaged codes, so we're defining identical structs. We don't need to change any of those parameters on the C++ side, but we do need to access them after the P/Invoked function has returned. My questions are: What is the best way to pass strings? Some are short (device id's which can be set by us), and some are file paths (which may contain Asian characters) Should I pass an IntPtr to the C# struct or should I just let the Marshaller take care of it by putting the struct type in the function signature? Should I be worried about any non-pointer datatypes like bools or enums (in other, related structs)? We have the treat warnings as errors flag set in C++ so we can't use the Microsoft extension for enums to force a datatype. Is P/Invoke actually the way to go? There was some Microsoft documentation about Implicit P/Invoke that said it was more type-safe and performant. For reference, here is one of the pairs of structs I've written so far: C++ /** Struct used for marshalling Scan parameters from managed to unmanaged code. */ struct ScanParameters { LPSTR deviceID; LPSTR spdClock; LPSTR spdStartTrigger; double spinRpm; double startRadius; double endRadius; double trackSpacing; UINT64 numTracks; UINT32 nominalSampleCount; double gainLimit; double sampleRate; double scanHeight; LPWSTR qmoPath; //includes filename LPWSTR qzpPath; //includes filename }; C# /// <summary> /// Struct used for marshalling scan parameters between managed and unmanaged code. /// </summary> [StructLayout(LayoutKind.Sequential)] public struct ScanParameters { [MarshalAs(UnmanagedType.LPStr)] public string deviceID; [MarshalAs(UnmanagedType.LPStr)] public string spdClock; [MarshalAs(UnmanagedType.LPStr)] public string spdStartTrigger; public Double spinRpm; public Double startRadius; public Double endRadius; public Double trackSpacing; public UInt64 numTracks; public UInt32 nominalSampleCount; public Double gainLimit; public Double sampleRate; public Double scanHeight; [MarshalAs(UnmanagedType.LPWStr)] public string qmoPath; [MarshalAs(UnmanagedType.LPWStr)] public string qzpPath; }

    Read the article

  • How can I set an image for background of GUI interface?

    - by enriched
    hey everyone, im having some troubles displaying the background image for a GUI interface in java. Here is what i have at the moment, and with current stage of code it shows default(gray) background. import javax.swing.*; import java.awt.event.*; import java.util.Scanner; import java.awt.*; import java.io.File; import javax.imageio.ImageIO; import java.awt.image.BufferedImage; import java.io.IOException; ////////////////////////////////// // 3nriched Games Presents: // // MIPS The Mouse!! // ////////////////////////////////// public class mipsMouseGUI extends JFrame implements ActionListener { private static String ThePDub = ("mouse"); //the password JPasswordField pass; JPanel panel; JButton btnEnter; JLabel lblpdub; public mipsMouseGUI() { BufferedImage image = null; try { //attempts to read picture from the folder image = ImageIO.read(getClass().getResource("/mousepics/mousepic.png")); } catch (IOException e) { //catches exceptions e.printStackTrace(); } ImagePanel panel = new ImagePanel(new ImageIcon("/mousepics/neonglowOnwill.png").getImage()); setIconImage(image); //sets icon picture setTitle("Mips The Mouse Login"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); pass = new JPasswordField(5); //sets password length to 5 pass.setEchoChar('@'); //hide characters as @ symbol pass.addActionListener(this); //adds action listener add(panel); //adds panel to frame btnEnter = new JButton("Enter"); //creates a button btnEnter.addActionListener(this);// Register the action listener. lblpdub = new JLabel(" Your Password: "); // label that says enter password panel.add(lblpdub, BorderLayout.CENTER);// adds label and inputbox panel.add(pass, BorderLayout.CENTER); // to panel and sets location panel.add(btnEnter, BorderLayout.CENTER); //adds button to panel pack(); // packs controls and setLocationRelativeTo(null); // Implicit "this" if inside JFrame constructor. setVisible(true);// makes them visible (duh) } public void actionPerformed(ActionEvent a) { Object source = a.getSource(); //char array that holds password char[] passy = pass.getPassword(); //characters array to string String p = new String(passy); //determines if user entered correct password if(p.equals(ThePDub)) { JOptionPane.showMessageDialog(null, "Welcome beta user: USERNAME."); } else JOptionPane.showMessageDialog(null, "You have enter an incorrect password. Please try again."); } public class ImagePanel extends JPanel { private BufferedImage img; public ImagePanel(String img) { this(new ImageIcon(img).getImage()); } public ImagePanel(Image img) { Dimension size = new Dimension(img.getWidth(null), img.getHeight(null)); } public void paintComponent(Graphics g) { g.drawImage(img, 0, 0, null); } } }

    Read the article

  • Play! Framework - Can my view template be localised when rendering it as an AsyncResult?

    - by avik
    I've recently started using the Play! framework (v2.0.4) for writing a Java web application. In the majority of my controllers I'm following the paradigm of suspending the HTTP request until the promise of a web service response has been fulfilled. Once the promise has been fulfilled, I return an AsyncResult. This is what most of my actions look like (with a bunch of code omitted): public static Result myActionMethod() { Promise<MyWSResponse> wsResponse; // Perform a web service call that will return the promise of a MyWSResponse... return async(wsResponse.map(new Function<MyWSResponse, Result>() { @Override public Result apply(MyWSResponse response) { // Validate response... return ok(myScalaViewTemplate.render(response.data())); } })); } I'm now trying to internationalise my app, but hit the following error when I try to render a template from an async method: [error] play - Waiting for a promise, but got an error: There is no HTTP Context available from here. java.lang.RuntimeException: There is no HTTP Context available from here. at play.mvc.Http$Context.current(Http.java:27) ~[play_2.9.1.jar:2.0.4] at play.mvc.Http$Context$Implicit.lang(Http.java:124) ~[play_2.9.1.jar:2.0.4] at play.i18n.Messages.get(Messages.java:38) ~[play_2.9.1.jar:2.0.4] at views.html.myScalaViewTemplate$.apply(myScalaViewTemplate.template.scala:40) ~[classes/:na] at views.html.myScalaViewTemplate$.render(myScalaViewTemplate.template.scala:87) ~[classes/:na] at views.html.myScalaViewTemplate.render(myScalaViewTemplate.template.scala) ~[classes/:na] In short, where I've got a message bundle lookup in my view template, some Play! code is attempting to access the original HTTP request and retrieve the accept-languages header, in order to know which message bundle to use. But it seems that the HTTP request is inaccessible from the async method. I can see a couple of (unsatisfactory) ways to work around this: Go back to the 'one thread per request' paradigm and have threads block waiting for responses. Figure out which language to use at Controller level, and feed that choice into my template. I also suspect this might not be an issue on trunk. I know that there is a similar issue in 2.0.4 with regards to not being able to access or modify the Session object which has recently been fixed. However I'm stuck on 2.0.4 for the time being, so is there a better way that I can resolve this problem?

    Read the article

< Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84  | Next Page >