Search Results

Search found 12934 results on 518 pages for 'magic methods'.

Page 430/518 | < Previous Page | 426 427 428 429 430 431 432 433 434 435 436 437  | Next Page >

• MS Access (Jet) transactions, workspaces & scope

  - by Eric G

  I am having trouble with committing a transaction (using Access 2003 DAO). It's acting as if I never had called BeginTrans -- I get error 3034 on CommitTrans, "You tried to commit or rollback a transaction without first beginning a transaction"; and the changes are written to the database (presumably because they were never wrapped in a transaction). However, BeginTrans is run, if you step through it. I am running it within the Access environment using the DBEngine(0) workspace. The tables I'm updating are all opened via a Jet database connection (to the same database) and updated using DAO.Recordset.update. The connection is opened before starting BeforeTrans. I'm not doing anything weird in the middle of the transaction like closing/opening connections or multiple workspaces etc. There is one nested transaction level (basically it's wrapping multiple transacted updates in an outer transaction, so if any fail they all fail). The inner transactions run without errors, it's the outer transaction that doesn't work. Here are a few things I've looked into and ruled out: The transaction is spread across several methods and BeginTrans and CommitTrans (and Rollback) are all in different places. But when I tried a simple test of running a transaction this way, it doesn't seem like this should matter. I thought maybe the database connection gets closed when it goes out of local scope, even though I have another 'global' reference to it (I'm never sure what DAO does with dbase connections to be honest). But this seems not to be the case -- right before the commit, the connection and its recordsets are alive (I can check their properties, EOF = False, etc.) My CommitTrans and Rollback are done within event callbacks. (Very basically, a parser program is throwing an 'onLoad' or 'onLoadFail' event at the end of parsing, which I am handling by either committing or rolling back the inserts I made during processing.) However, again, trying a simple test, it doesn't seem like this should matter. Any ideas why this isn't working for me? Thanks.

  Read the article

• Achieving Thread-Safety

  - by Smasher

  Question How can I make sure my application is thread-safe? Are their any common practices, testing methods, things to avoid, things to look for? Background I'm currently developing a server application that performs a number of background tasks in different threads and communicates with clients using Indy (using another bunch of automatically generated threads for the communication). Since the application should be highly availabe, a program crash is a very bad thing and I want to make sure that the application is thread-safe. No matter what, from time to time I discover a piece of code that throws an exception that never occured before and in most cases I realize that it is some kind of synchronization bug, where I forgot to synchronize my objects properly. Hence my question concerning best practices, testing of thread-safety and things like that. mghie: Thanks for the answer! I should perhaps be a little bit more precise. Just to be clear, I know about the principles of multithreading, I use synchronization (monitors) throughout my program and I know how to differentiate threading problems from other implementation problems. But nevertheless, I keep forgetting to add proper synchronization from time to time. Just to give an example, I used the RTL sort function in my code. Looked something like FKeyList.Sort (CompareKeysFunc); Turns out, that I had to synchronize FKeyList while sorting. It just don't came to my mind when initially writing that simple line of code. It's these thins I wanna talk about. What are the places where one easily forgets to add synchronization code? How do YOU make sure that you added sync code in all important places?

  Read the article

• How do I use an array as an object attribute in Perl?

  - by superstar

  Hello guys, I need some help regarding the arrays in Perl This is the constructor i have. sub new { my $class = shift; my @includeobjects = (); my @excludeobjects = (); my $Packet = { _PacketName => shift, _Platform => shift, _Version => shift, @_IncludePath => @includeobjects, }; bless $Packet, $class; return $Packet; } sub SetPacketName { my ( $Packet, $PacketName ) = @_; $Packet->{_PacketName} = $PacketName if defined($PacketName); return $Packet->{_PacketName}; } sub SetIncludePath { my ( $Packet, @IncludePath ) = @_; $Packet->{@_IncludePath} = @IncludePath; return $Packet->{@_IncludePath}; } sub GetPacketName { my( $Packet ) = @_; return $Packet->{_PacketName}; } sub GetIncludePath { my( $Packet ) = @_; return $Packet->{@_IncludePath}; } The get and set methods work fine for PacketName. But since IncludePath is an array, I could not get it work. The declaration is what I am not able to get right.

  Read the article

• How to encapsulate a third party complex object structure?

  - by tangens

  Motivation Currently I'm using the java parser japa to create an abstract syntax tree (AST) of a java file. With this AST I'm doing some code generation (e.g.: if there's an annotation on a method, create some other source files, ...) Problem When my code generation becomes more complex, I've to dive deeper into the structure of the AST (e.g. I have to use visitors to extract some type information of method parameters). But I'm not sure if I want to stay with japa or if I will change the parser library later. Because my code generator uses freemarker (which isn't good at automatic refactoring) I want the interface that it uses to access the AST information to be stable, even if I decide to change the java parser. Question What's the best way to encapsulate complex datastructures of third party libraries? I could create my own datatypes and copy the parts of the AST that I need into these. I could create lots of specialized access methods that work with the AST and create exactly the infos I need (e.g. the fully qualified return type of a method as one string, or the first template parameter of a class). I could create wrapper classes for the japa datastructures I currently need and embed the japa types inside, so that I can delegate requests to the japa types and transform the resulting japa types to my wrapper classes again. Which solution should I take? Are there other (better) solutions to this problem?

  Read the article

• How do you make life easier for yourself when developing a really large database

  - by Hannes de Jager

  I am busy developing 2 web based systems with MySql databases and the amount of tables/views/stored routines is really becoming a lot and it is more and more challenging to handle the complexity. Now in programming languages we have namespacing e.g. Java packages, C++ namespaces to partition the software, grouping it together to make things more understandable. Databases on the other hand have more of a flat structure (MySql at least) e.g. tables and stored procedures are on the same level. So one have to be more creative, creating naming conventions, perhaps use more than one database or using tools to visualize things. What methods do you use to ease the pain? To be effective while developing your databases? To not get lost in a sea of tables and fields and stored procs? Feel free to mention tools you use also, but try to restrict it to open source and preferably Linux solutions if thats OK. b.t.w How many tables would a database have to be considered large in terms of design?

  Read the article

• How do I use Core Data with the Cocoa Text Input system?

  - by the Joel

  Hobbyist Cocoa programmer here. Have been looking around all the usual places, but this seems relatively under-explained: I am writing something a little out of the ordinary. It is much simpler than, but similar to, a desktop publishing app. I want editable text boxes on a canvas, arbitrarily placed. This is document-based and I’d really like to use Core Data. Now, The cocoa text-handling system seems to deal with a four-class structure: NSTextStorage, NSLayoutManager, NSTextContainer and finally NSTextView. I have looked into these and know how to use them, sort of. Have been making some prototypes and it works for simple apps. The problem arrives when I get into persistency. I don't know how to, by way of Cocoa Bindings or something else, store the contents of NSTextStorage (= the actual text) in my managed object context. I have considered overriding methods pairs like -words, -setWords: in these objects. This would let me link the words to a String, which I know how to store in Core Data. However, I’d have to override any method that affects the text - and that seems a little much. Thankful for any insights.

  Read the article

• Setting String as Image Source in C#

  - by Dan

  UPDATE: Okay I've changed my code to this: if (appSettings.Contains("image")) { Uri uri = new Uri( (string)appSettings["image"] + ".jpg", UriKind.Absolute); ImageSource imgSource = new BitmapImage(uri); myImage.Source = imgSource; } else { Uri uriDefault = new Uri("default.jpg", UriKind.Absolute); ImageSource imgSourceDefault = new BitmapImage(uriDefault); myImage.Source = imgSourceDefault; } But now I get "Invalid URI: The format of the URI could not be determined". Well I've looked up several methods to fix this in my Windows Phone 7 app but I can't seem to find anything that works. What confuses me is that I've done something just like this before with no problem, so I'm not sure why it's not working. The code causing me the problem is this: if (appSettings.Contains("image")) { myImage.Source = (string)appSettings["image"]; } else { myImage.Source = "default.jpg"; } The error I get is this "Cannot implicitly convert type 'string' to 'System.Windows.Media.ImageSource". The reason this confuses me is because I did this Twitter app tutorial: http://weblogs.asp.net/scottgu/archive/2010/03/18/building-a-windows-phone-7-twitter-application-using-silverlight.aspx , in which you bind the image source directly to a string. So what can I do to remedy this?

  Read the article

• How do I resize an iframe with dynamic content?

  - by Middletone

  I'm populating an iframe with some contents that are injected into it but I'm unable to size it correctly. I've tried a variety of methods but here is the most recent code. After populating the iframe with an html based mail message it doesn't seem to register the scroll height. <iframe scrolling="no" width="100%" onload="javascript:(LoadIFrame(this));" > HTML content goes here. Make sure it's long enough to need to scroll before testing. </iframe> <script type="text/javascript"> function LoadIFrame(iframe) { $("iframe").each(function() { $(this).load(function() { var doc = this.document; if (this.contentDocument) { doc = this.contentDocument; } else if (this.contentWindow) { doc = this.contentWindow.document; } else if (this.document) { doc = this.document; } this.height = (doc.body.scrollHeight + 50) + 'px'; this.onload = ''; }); txt = $(this).text(); var doc = this.document; if (this.contentDocument) { doc = this.contentDocument; } else if (this.contentWindow) { doc = this.contentWindow.document; } else if (this.document) { doc = this.document; } doc.open(); doc.writeln(txt); doc.close(); }); } </script>

  Read the article

• C# - Advantages/Disadvantages of different implementations for Comparing Objects

  - by Kevin Crowell

  This questions involves 2 different implementations of essentially the same code. First, using delegate to create a Comparison method that can be used as a parameter when sorting a collection of objects: class Foo { public static Comparison<Foo> BarComparison = delegate(Foo foo1, Foo foo2) { return foo1.Bar.CompareTo(foo2.Bar); }; } I use the above when I want to have a way of sorting a collection of Foo objects in a different way than my CompareTo function offers. For example: List<Foo> fooList = new List<Foo>(); fooList.Sort(BarComparison); Second, using IComparer: public class BarComparer : IComparer<Foo> { public int Compare(Foo foo1, Foo foo2) { return foo1.Bar.CompareTo(foo2.Bar); } } I use the above when I want to do a binary search for a Foo object in a collection of Foo objects. For example: BarComparer comparer = new BarComparer(); List<Foo> fooList = new List<Foo>(); Foo foo = new Foo(); int index = fooList.BinarySearch(foo, comparer); My questions are: What are the advantages and disadvantages of each of these implementations? What are some more ways to take advantage of each of these implementations? Is there a way to combine these implementations in such a way that I do not need to duplicate the code? Can I achieve both a binary search and an alternative collection sort using only 1 of these methods?

  Read the article

• Componentizing complex functionality in an MVC web app

  - by NXT

  Hi Everyone, This is question about MVC web-app architecture, and how it can be extended to handle componentizing moderately complex units of functionality. I have an MVC style web-app with a customer facing credit card charge page. I've been asked to allow the admins to enter credit card payments as well, for times when credit cards are taken over the phone. The customer facing credit card charge section of the website is currently it's own controller, with approximately 3 pages and a login. That controller is responsible for: Customer login credential authentication Credit card data collection Calling a library to do the actual charge. reporting the results to the user. I would like to extract the card data collection pages into a component of some kind so that I can easily reuse the code on the admin side of the app. Right now my components are limited to single "view" pages with PHP style embedded Perl code. This is a simple, custom MVC framework written in Perl. Right now, controllers are called directly from the framework to service web requests. My idea is to allow controllers to be called from other controllers, so that I can componentize more complex functionality. For simplicity I think I prefer composition over inheritance, even though it will require writing a bunch of pass-through methods (actions). Being Perl, I could in theory do multiple inheritance. I'm wondering if anyone with experience in other MVC web frameworks can comment on how this sort of thing is usually done. Thank you.

  Read the article

• How to overcome the programmer's block ?

  - by Nicolas Dorier

  How do you do when, during the development of your application, you can't decide yourself what to do next. You have no problem technically speaking, you have no problem to write clean code BUT you have a problem to decide yourself on what to code now. And you spend time thinking and thinking again on your design, in the car, in the shower, and you cannot write a single line of code... I think we call this "analysis paralysis". I hate being in this state ! How can you avoid this ? How do you do to not fall in this state ? I think this occurs when we are writting a big chunk of code with no visible improvement, but I'm not sure... UPDATE Like some of you said, this problem is also what we call the "programmer's block" (analogy with the writer's block). Doing some TDD doesn't help because I'm stuck, I can't decide myself what class to code, what methods to put inside (even a name of method). Though I admit that it helps to break a big chunk of code into smaller ones. Like Talesh said my head becomes full of "what-if".

  Read the article

• Best way to catch a WCF exception in Silverlight?

  - by wahrhaft

  I have a Silverlight 2 application that is consuming a WCF service. As such, it uses asynchronous callbacks for all the calls to the methods of the service. If the service is not running, or it crashes, or the network goes down, etc before or during one of these calls, an exception is generated as you would expect. The problem is, I don't know how to catch this exception. Because it is an asynchronous call, I can't wrap my begin call with a try/catch block and have it pick up an exception that happens after the program has moved on from that point. Because the service proxy is automatically generated, I can't put a try/catch block on each and every generated function that calls EndInvoke (where the exception actually shows up). These generated functions are also surrounded by External Code in the call stack, so there's nowhere else in the stack to put a try/catch either. I can't put the try/catch in my callback functions, because the exception occurs before they would get called. There is an Application_UnhandledException function in my App.xaml.cs, which captures all unhandled exceptions. I could use this, but it seems like a messy way to do it. I'd rather reserve this function for the truly unexpected errors (aka bugs) and not end up with code in this function for every circumstance I'd like to deal with in a specific way. Am I missing an obvious solution? Or am I stuck using Application_UnhandledException? [Edit] As mentioned below, the Error property is exactly what I was looking for. What is throwing me for a loop is that the fact that the exception is thrown and appears to be uncaught, yet execution is able to continue. It triggers the Application_UnhandledException event and causes VS2008 to break execution, but continuing in the debugger allows execution to continue. It's not really a problem, it just seems odd.

  Read the article

• Java Function Analysis

  - by khan

  Okay..I am a total Python guy and have very rarely worked with Java and its methods. The condition is that I have a got a Java function that I have to explain to my instructor and I have got no clue about how to do so..so if one of you can read this properly, kindly help me out in breaking it down and explaining it. Also, i need to find out any flaw in its operation (i.e. usage of loops, etc.) if there is any. Finally, what is the difference between 'string' and 'string[]' types? public static void search(String findfrom, String[] thething){ if(thething.length > 5){ System.err.println("The thing is quite long"); } else{ int[] rescount = new int[thething.length]; for(int i = 0; i < thething.length; i++){ String[] characs = findfrom.split("[ \"\'\t\n\b\f\r]", 0); for(int j = 0; j < characs.length; j++){ if(characs[j].compareTo(thething[i]) == 0){ rescount[i]++; } } } for (int j = 0; j < thething.length; j++) { System.out.println(thething[j] + ": " + rescount[j]); } } }

  Read the article

• Drawing graphics on top of a JButton

  - by trinth

  I have a situation wherein I have a bunch of JButtons on a GridLayout. I need each of the JButtons to have: a background image (but retain the ability to keep the default button look if needed) custom graphics drawn on top by other classes I have no trouble with the background image, since I am using setIcon() but I am having problems drawing things on top of the background. At one point I was able to draw on top of the button, but after the button was clicked, the drawings disappeared. How can make the button keep this drawing state? Basically, I need a way for my JButtons to have public methods that would allow another class to draw anything on it such as: public void drawSomething() { Graphics g = this.getGraphics(); g.drawOval(3,2,2,2); repaint(); } or public Graphics getGraphics() { return this.getGraphics(); } then another class could do this: button.getGraphics().drawSomething(); The latter is more what I am looking for but the first is equally useful. Is there any way to go about this? Also, overriding the parent class method paintComponent() doesn't help since I need each button to have different graphics.

  Read the article

• what use does the javascript forEach method have (that map can't do)?

  - by JohnMerlino

  Hey all, The only difference I see in map and foreach is that map is returning an array and foreach is not. However, I don't even understand the last line of the foreach method "func.call(scope, this[i], i, this);". For example, isn't "this" and "scope" referring to same object and isn't this[i] and i referring to the current value in the loop? I noticed on another post someone said "Use forEach when you want to do something on the basis of each element of the list. You might be adding things to the page, for example. Essentially, it's great for when you want "side effects". I don't know what is meant by side effects. Array.prototype.map = function(fnc) { var a = new Array(this.length); for (var i = 0; i < this.length; i++) { a[i] = fnc(this[i]); } return a; } Array.prototype.forEach = function(func, scope) { scope = scope || this; for (var i = 0, l = this.length; i < l; i++) func.call(scope, this[i], i, this); } Finally, are there any real uses for these methods in javascript (since we aren't updating a database) other than to manipulate numbers like this: alert([1,2,3,4].map(function(x){ return x + 1})); //this is the only example I ever see of map in javascript. Thanks for any reply.

  Read the article

• A question about entities, roles and interfaces in Entity Framework 4.

  - by mvole

  Hi, I am an experienced .NET developer but new to EF - so please bear with me. I will use an example of a college application to illustrate my problem. I have these user roles: Lecturer, Student, Administrator. In my code I envisage working with these entities as distinct classes so e.g. a Lecturer teaches a collection of Students. And work with 'is Student' 'TypeOf' etc. Each of these entities share lots of common properties/methods e.g. they can all log onto the system and do stuff related to their role. In EF designer I can create a base entity Person (or User...) and have Lecturer, Student and Administrator all inherit from that. The difficulty I have is that a Lecturer can be an Administrator - and in fact on occasion a Student can be a Lecturer. If I were to add other entities such as Employee and Warden then this gets even more of an issue. I could presumably work with Interfaces so a person could implement ILecturer and IStudent, however I do not see how this fits within EF. I would like to work within the EF designer if possible and I'm working model-first (coding in C#). So any help and advice/samples would be very welcome and much appreciated. Thanks

  Read the article

• c++ Design pattern for CoW, inherited classes, and variable shared data?

  - by krunk

  I've designed a copy-on-write base class. The class holds the default set of data needed by all children in a shared data model/CoW model. The derived classes also have data that only pertains to them, but should be CoW between other instances of that derived class. I'm looking for a clean way to implement this. If I had a base class FooInterface with shared data FooDataPrivate and a derived object FooDerived. I could create a FooDerivedDataPrivate. The underlying data structure would not effect the exposed getters/setters API, so it's not about how a user interfaces with the objects. I'm just wondering if this is a typical MO for such cases or if there's a better/cleaner way? What peeks my interest, is I see the potential of inheritance between the the private data classes. E.g. FooDerivedDataPrivate : public FooDataPrivate, but I'm not seeing a way to take advantage of that polymorphism in my derived classes. class FooDataPrivate { public: Ref ref; // atomic reference counting object int a; int b; int c; }; class FooInterface { public: // constructors and such // .... // methods are implemented to be copy on write. void setA(int val); void setB(int val); void setC(int val); // copy constructors, destructors, etc. all CoW friendly private: FooDataPrivate *data; }; class FooDerived : public FooInterface { public: FooDerived() : FooInterface() {} private: // need more shared data for FooDerived // this is the ???, how is this best done cleanly? };

  Read the article

• are custom classes imported API included in .class files?

  - by kyrogue

  i have a question, i have a custom class which imports java.sql.; and i am creating a jsp page, in the jsp page, i did a page import of the custom class , however when i tried to call my custom class database methods it cant work. only when i did a page import of java.sql. did it work. so are custom classes imported API included in .class files? An error occurred at line: 6 in the jsp file: /resetpw.jsp Statement cannot be resolved to a type 3: 4: <% 5: db.connect(); 6: Statement stmt = db.getConnection().createStatement(); 7: ResultSet rs = stmt.executeQuery("SELECT * FROM created_accounts"); 8: 9: An error occurred at line: 7 in the jsp file: /resetpw.jsp ResultSet cannot be resolved to a type 4: <% 5: db.connect(); 6: Statement stmt = db.getConnection().createStatement(); 7: ResultSet rs = stmt.executeQuery("SELECT * FROM created_accounts"); 8: 9: 10: Stacktrace: org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:93) org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330) org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:451) org.apache.jasper.compiler.Compiler.compile(Compiler.java:319) org.apache.jasper.compiler.Compiler.compile(Compiler.java:298) org.apache.jasper.compiler.Compiler.compile(Compiler.java:286) org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:565) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:309) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259) javax.servlet.http.HttpServlet.service(HttpServlet.java:729) note The full stack trace of the root cause is available in the Apache Tomcat/5.5.31 logs. edited. added what error will come up if i did not do a page import of java.sql.*;

  Read the article

• Creating a RESTful API - HELP!

  - by Martin Cox

  Hi Chaps Over the last few weeks I've been learning about iOS development, which has naturally led me into the world of APIs. Now, searching around on the Internet, I've come to the conclusion that using the REST architecture is very much recommended - due to it's supposed simplicity and ease of implementation. However, I'm really struggling with the implementation side of REST. I understand the concept; using HTTP methods as verbs to describe the action of a request and responding with suitable response codes, and so on. It's just, I don't understand how to code it. I don't get how I map a URI to an object. I understand that a GET request for domain.com/api/user/address?user_id=999 would return the address of user 999 - but I don't understand where or how that mapping from /user/address to some method that queries a database has taken place. Is this all coded in one php script? Would I just have a method that grabs the URI like so: $array = explode("/", ltrim(rtrim($_SERVER['REQUEST_URI'], "/"), "/")) And then cycle through that array, first I would have a request for a "user", so the PHP script would direct my request to the user object and then invoke the address method. Is that what actually happens? I've probably not explained my thought process very well there. The main thing I'm not getting is how that URI /user/address?id=999 somehow is broken down and executed - does it actually resolve to code? class user(id) { address() { //get user address } } I doubt I'm making sense now, so I'll call it a day trying to explain further. I hope someone out there can understand what I'm trying to say! Thanks Chaps, look forward to your responses. Martin p.s - I'm not a developer yet, I'm learning :)

  Read the article

• about c# OBJECTS and the Possibilties it has.

  - by user527825

  As a novice programmer and i always wonder about c# capabilities.i know it is still early to judge that but all i want to know is can c# do complex stuffs or something outside windows OS. 1- I think c# is a proprietary language (i don't know if i said that right) meaning you can't do it outside visual studio or windows. 2-also you cant create your own controller(called object right?) like you are forced to use these available in toolbox and their properties and methods. 3-can c# be used with openGL API or DirectX API . 4-Finally it always bothers me when i think i start doing things in visual studio, i know it sounds arrogant to say but sometimes i feel that i don't like to be forced to use something even if its helpful, like i feel (do i have the right to feel?) that i want to do all things by myself? don't laugh i just feel that this will give me a better understanding. 5- is visual c# is like using MaxScript inside 3ds max in that c# is exclusive to do windows and forms and components that are windows related and maxscript is only for 3d editing and manipulation for various things in the software. If it is too difficult for a beginner i hope you don't answer the fourth question as i don't have enough motivation and i want to keep the little i have. thank you for your time. Note: 1-sorry for my English, i am self taught and never used the language with native speakers so expect so errors. 2-i have a lot of questions regarding many things, what is the daily ratio you think for asking (number of questions) that would not bother the admins of the site and the members here. thank you for your time.

  Read the article

• c# multi inheritance

  - by user326839

  So ive got a base class which requires a Socket: class Sock { public Socket s; public Sock(Socket s) { this.s = s; } public virtual void Process(byte[] data) { } ... } then ive got another class. if a new socket gets accepted a new instance of this class will be created: class Game : Sock { public Random Random = new Random(); public Timerr Timers; public Test Test; public Game(Socket s) : base(s) { } public static void ReceiveNewSocket(object s) { Game Client = new Game((Socket)s); Client.Start(); } public override void Process(byte[] buf) { Timers = new Timerr(s); Test = new Test(s); Test.T(); } } in the Sock class ive got a virtual function that gets overwritten by the Game class.(Process function) in this function im calling a function from the Test Class(Test+ Timerr Class: class Test : Game { public Test(Socket s) : base(s) { } public void T() { Console.WriteLine(Random.Next(0, 10)); Timers.Start(); } } class Timerr : Game { public Timerr(Socket s) : base(s) { } public void Start() { Console.WriteLine("test"); } } ) So in the Process function im calling a function in Test. And in this function(T) i need to call a function from the Timerr Class.But the problem is its always NULL , although the constructor is called in Process. And e.g. the Random Class can be called, i guess its because its defined with the constructor.: public Random Random = new Random(); and thats why the other classes(without a constructor): public Timerr Timers; public Test Test; are always null in the inherited class Test.But its essentiel that i call other Methods of other classes in this function.How could i solve that?

  Read the article

• (nested) user controls within a mvp pattern causing sporadic problems

  - by LLEA

  hi everyone, I have a serious problem with nested user controls (UCs) in WinForms while trying to implement the mvp pattern (passive view). The project consists of one model (designed as a singleton) and a set of different presenters with corresponding view interfaces. To avoid one huge view interface and therefore an overloaded main UI, I decided to make use of a set of different UCs. Each UC has one view interface and one presenter that can access the model. But there are nested UCs: meaning that one specialised UC implements sort of a basic UC. The main UI just represents a container for all those UCs. So far, so good (if not, please ask)?! There are two problems that I am facing now (but I guess both are of the same origin): From time to time it is not possible anymore to load the UCs and test them within the Visual Studio 2008 User Control Test Container. The error message just says that a project with an output type of class library cannot be started directly etc. I can "handle" that by unloading all UC projects and reloading them afterwards. (I guess the references to all mvp components and other UCs are then updated). Assuming that the implementation of my mvp pattern is okay and all those UCs are testable within the VS Test Container at a certain time - there is the biggest problem still left: I am not able to add any UC (even the basic and unnested ones) to a simple Form (UI). The error message: error message.jpg Could it be that my basic UC causes all these Problems?! It consists of two simple ComboBoxes and implements a basic presenter and basic view interface. Whenever I add this UC to a different UC the VS designer adds two references to the public getter methods of the UC as resources. I then manually remove those resources from the resx-file and commend the corresponding lines in the designer file. thx in advance

  Read the article

• deleting object with template for int and object

  - by Yokhen

  Alright so Say I have a class with all its definition, bla bla bla... template <class DT> class Foo{ private: DT* _data; //other stuff; public: Foo(DT* data){ _data = data } virtual ~Foo(){ delete _data } //other methods }; And then I have in the main method: int main(){ int number = 12; Foo<anyRandomClass>* noPrimitiveDataObject = new Foo<anyRandomClass>(new anyRandomClass()); Foo<int>* intObject = new Foo<int>(number); delete noPrimitiveDataObject; //Everything goes just fine. delete intObject; //It messes up here, I think because primitive data types such as int are allocated in a different way. return 0; } My question is: What could I do to have both delete statements in the main method work just fine? P.S.: Although I have not actually compiled/tested this specific code, I have reviewed it extensively (as well as indented. You're welcome.), so if you find a mistake, please be nice. Thank you.

  Read the article

• ASP.NET AJAX weirdness

  - by LoveMeSomeCode

  Ok, I thought I understood these topics well, but I guess not, so hopefully someone here can clear this up. Page.IsAsync seems to be broken. It always returns false. But ScriptManager.IsInAsyncPostBack seems to work, sort of. It returns true during the round trip for controls inside UpdatePanels. This is good; I can tell if it's a partial postback or a regular one. ScriptManager.IsInAsyncPostBack returns false however for async Page Methods. Why is this? It's not a regular postback, I'm just calling a public static method on the page. It causes a problem because I also realized that if you have a control with AutoPostBack = false, it won't trigger a postback on it's own, but if it has an event handler on the page, that event handler code WILL run on the next postback, regardless of how the postback occurred, IF the value has changed. i.e. if I tweak a dropdown and then hit a button, that dropdown's handler code will fire. This is ok, except that it will also happen during Page Method calls, and I have no way to know the difference. Any thoughts?

  Read the article

• Learning libraries without books or tutorials

  - by Kawili-wili

  While many ask questions about where to find good books or tutorials, I'd like to take the opposite tack. I consider myself to be an entry-level programmer ready to move up to mid-level. I have written code in c, c++, c#, perl, python, clojure, vb, and java, so I'm not completely clueless. Where I see a problem in moving to the next level is learning to make better use of the literally hundreds upon hundreds of libraries available out there. I seem paralyzed unless there is a specific example in a book or tutorial to hand-hold me, yet I often read in various forums where another programmer attempts to assist with a question. He/she will look through the docs or scan the available classes/methods in their favorite IDE and seem to grok what's going on in a relatively short period of time, even if they had no previous experience with that specific library or function. I yearn to break the umbilical chord of constantly spending hour upon hour searching and reading, searching and reading, searching and reading. Many times there is no book or tutorial, or if there is, the discussion glosses over my specific needs or the examples shown are too far off the path for the usage I had in mind or the information is outdated and makes use of deprecated components or the library itself has fallen out of mainstream, yet is still perfectly usable (but no docs, books, or tutorials to hand-hold). My question is: In the absence of books or tutorials, what is the best way to grok new or unfamiliar libraries? I yearn to slicken the grok path so I can get down to the business of doing what I love most -- coding.

  Read the article

< Previous Page | 426 427 428 429 430 431 432 433 434 435 436 437  | Next Page >