Search Results

Search found 7666 results on 307 pages for 'pointer to member'.

Page 140/307 | < Previous Page | 136 137 138 139 140 141 142 143 144 145 146 147  | Next Page >

  • An interview question

    - by maddy
    Hi, The questions shown below is an interview question Q)You are given have a datatype, say X in C. The requirement is to get the size of the datatype, without declaring a variable or a pointer variable of that type, And, of course without using sizeof operator ! I am not sure if this question was asked before in SO. Thanks and regards Maddy

    Read the article

  • Pointers to threads

    - by viswanathan
    Suppose i have pointer to a thread like this CWinThread *m_pThread = AfxBeginThread(StartThread, this, THREAD_PRIORITY_NORMAL, 0, 0); Now in my StartThread function assume i did all operations and the function returned like this UINT CClassThread::StartThread(LPVOID pVoid) { return true; } Will my m_pThread be invalid when the return statement is executed?

    Read the article

  • warning: returning reference to temporary

    - by Jack
    I have a function like this const string &SomeClass::Foo(int Value) { if (Value < 0 or Value > 10) return ""; else return SomeClass::StaticMember[i]; } I get warning: returning reference to temporary. Why is that? I thought the both values the function returns (reference to const char* "" and reference to a static member) cannot be temporary.

    Read the article

  • Java Log ==> JTextArea

    - by asmo
    Need: Output a Java application's log into a GUI component, such as a JTextArea. Concern: Need to log things from any class, in a static manner. However, the GUI logger component must not be static (obviously) as it's the member of a parent component. What should I do?

    Read the article

  • Freeing memory twice

    - by benjamin button
    Hi, AFAIK, freeing a NULL pointer will result in nothing. I mean nothing is being done by the compiler/no functionality is performed. Still, I do see some statements where people say that one of the scenarios where memory corruption can occur is "freeing memory twice"? Is this still true?

    Read the article

  • Clojure vars and Java static methods

    - by j-g-faustus
    I'm a few days into learning Clojure and are having some teething problems, so I'm asking for advice. I'm trying to store a Java class in a Clojure var and call its static methods, but it doesn't work. Example: user=> (. java.lang.reflect.Modifier isPrivate 1) false user=> (def jmod java.lang.reflect.Modifier) #'user/jmod user=> (. jmod isPrivate 1) java.lang.IllegalArgumentException: No matching method found: isPrivate for class java.lang.Class (NO_SOURCE_FILE:0) at clojure.lang.Compiler.eval(Compiler.java:4543) From the exception it looks like the runtime expects a var to hold an object, so it calls .getClass() to get the class and looks up the method using reflection. In this case the var already holds a class, so .getClass() returns java.lang.Class and the method lookup obviously fails. Is there some way around this, other than writing my own macro? In the general case I'd like to have either an object or a class in a varible and call the appropriate methods on it - duck typing for static methods as well as for instance methods. In this specific case I'd just like a shorter name for java.lang.reflect.Modifier, an alias if you wish. I know about import, but looking for something more general, like the Clojure namespace alias but for Java classes. Are there other mechanisms for doing this? Edit: Maybe I'm just confused about the calling conventions here. I thought the Lisp (and by extension Clojure) model was to evaluate all arguments and call the first element in the list as a function. In this case (= jmod java.lang.reflect.Modifier) returns true, and (.getName jmod) and (.getName java.lang.reflect.Modifier) both return the same string. So the variable and the class name clearly evaluate to the same thing, but they still cannot be called in the same fashion. What's going on here? Edit 2 Answering my second question (what is happening here), the Clojure doc says that If the first operand is a symbol that resolves to a class name, the access is considered to be to a static member of the named class... Otherwise it is presumed to be an instance member http://clojure.org/java_interop under "The Dot special form" "Resolving to a class name" is apparently not the same as "evaluating to something that resolves to a class name", so what I am trying to do here is something the dot special form does not support.

    Read the article

  • Deriving from a component and implementing IDisposable properly

    - by PaulH
    I have a Visual Studio 2008 C# .NET 2.0 CF project with an abstract class derived from Component. From that class, I derive several concrete classes (as in my example below). But, when I go to exit my Form, though the Form's Dispose() member is called and components.Dispose() is called, my components are never disposed. Can anybody suggest how I can fix this design? public abstract class SomeDisposableComponentBase : Component { private System.ComponentModel.IContainer components; protected SomeDisposableComponentBase() { Initializecomponent(); } protected SomeDisposableComponentBase(IContainer container) { container.Add(this); Initializecomponent(); } private void InitializeComponent() { components = new System.ComponentModel.Container(); } protected abstract void Foo(); #region IDisposable Members bool disposed_; /// Warning 60 CA1063 : Microsoft.Design : Ensure that 'SomeDisposableComponentBase.Dispose()' is declared as public and sealed.* public void Dispose() { // never called Dispose(true); GC.SuppressFinalize(this); } protected virtual void Dispose(bool disposing) { // never called if (!disposed_) { if (disposing && (components != null)) { components.Dispose(); } disposed_ = true; } base.Dispose(disposing); } #endregion } public SomeDisposableComponent : SomeDisposableComponentBase { public SomeDisposableComponent() : base() { } public SomeDisposableComponent(IContainer container) : base(container) { } protected override void Foo() { // Do something... } protected override void Dispose(bool disposing) { // never called base.Dispose(disposing); } } public partial class my_form : Form { private SomeDisposableComponentBase d_; public my_form() { InitializeComponent(); if (null == components) components = new System.ComponentModel.Container(); d_ = new SomeDisposableComponent(components); } /// exit button clicked private void Exit_Click(object sender, EventArgs e) { this.Close(); } /// from the my_form.designer.cs protected override void Dispose(bool disposing) { if (disposing && (components != null)) { // this function is executed as expected when the form is closed components.Dispose(); } base.Dispose(disposing); } } *I note that FX-Cop is giving me a hint here. But, if I try to declare that function as sealed, I get the error: error CS0238: 'SomeDisposableComponentBase.Dispose()' cannot be sealed because it is not an override Declaring that function an override leads to: 'SomeDisposableComponentBase.Dispose()': cannot override inherited member 'System.ComponentModel.Component.Dispose()' because it is not marked virtual, abstract, or override Thanks, PaulH

    Read the article

  • C#: Abstract classes need to implement interfaces?

    - by bguiz
    My test code in C#: namespace DSnA { public abstract class Test : IComparable { } } Results in the following compiler error: error CS0535: 'DSnA.Test' does not implement interface member 'System.IComparable.CompareTo(object)' Since the class Test is an abstract class, why does the compiler require it to implement the interface? Shouldn't this requirement only be compulsory for concrete classes?

    Read the article

  • Binding Jar Library

    - by Juliano
    I'm trying to bind a jar library (jCIFS) on MFA, but i'm stuck on some errors, like this one: 'Jcifs.Util.MD4' does not implement inherited abstract member 'Java.Security.MessageDigestSpi.EngineDigest() After some research, i found some topics about this, telling to edit the metadata to change the permissions of the classes, like this: <attr path="/api/package[@name='java.security']/class[@name='MessageDigestSpi']/method[@name='engineDigest']" name="visibility">public</attr> But the error didn't change, and a still won't get what this error means. Anyone ? Thanks.

    Read the article

  • Are there any good books to learn C++ if you already know Java and C#

    - by JF LR
    Hi, I would like to know if you have any good books that teach C++ programming without repeating basic stuff. In fact, I already well know Java and C#. I also have a basic knowledge in C and assembly, so I understand a little bit pointer arithmetic, manual memory management and heap based allocation. I was looking at O'Reilly's C++ in a Nutshell and was also wondering if this book would be a good choice. Thank you

    Read the article

  • Practical examples of using symbols in Scala?

    - by Jesper
    Scala has symbols - names that start with a single quote ' and which are a kind of string constants. I know symbols from Ruby (where they start with a colon). In Ruby they are used for some meta-programming tasks, like generating getters and setters for member variables (for example attr_reader :name to generate a getter for name). I haven't seen a lot of use of symbols in Scala code yet. What are practical uses for symbols in Scala?

    Read the article

  • Creating a console in Java

    - by DeadMG
    When I try to use java.lang.System.console(), I get a null pointer. I can still write to out and read from in, but this only works when I run straight from my IDE. When I run the .jar file directly, nothing happens. How can I create a console like I'd see using std::cout for use in Java?

    Read the article

  • How to access the CGColor property of UIColor in CGContextSetFillColorWithColor?

    - by Azeworai
    CGContextSetFillColorWithColor(g, [UIColor greyColor].CGColor); I'm trying to follow O'Reilly's iPhone Game Development book on page 73 Chapter 3 but I'm running into a compile error that states error: request for member 'CGColor' in something not a structure or union According to the book's errata page this is an unconfirmed errata in the book. I'm hoping that someone could help me replace that line of code to something that works. The example project can be downloaded from sourceforge at this link.

    Read the article

  • Does the openssl command line do key strengthening?

    - by chotchki
    If I run the openssl command line in hmac mode (as below), is the key used for the hmac used directly or is it hashed before using it as the key? echo "foo" | openssl dgst -sha256 -binary -hmac "test" | openssl base64 Similarly, when encrypting a file with openssl (as below)is the pass phrase hashed with the salt? (If so how is it done? A pointer to the right source file would be even better.) openssl enc -salt

    Read the article

  • How to count JavaScript array objects?

    - by Nikita Sumeiko
    When I have a JavaScript array like this: var member = { "mother": { "name" : "Mary", "age" : "48" }, "father": { "name" : "Bill", "age" : "50" }, "brother": { "name" : "Alex", "age" : "28" } } How to count objects in this array?!I mean how to get a counting result 3, because there're only 3 objects inside: mother, father, brother?!

    Read the article

  • Java app makes screen display unresponsive after 10 minutes of user idle time

    - by Ross
    I've written a Java app that allows users to script mouse/keyboard input (JMacro, link not important, only for the curious). I personally use the application to automate character actions in an online game overnight while I sleep. Unfortunately, I keep coming back to the computer in the morning to find it unresponsive. Upon further testing, I'm finding that my application causes the computer to become unresponsive after about 10 minutes of user idle time (even if the application itself it simulating user activity). I can't seem to pin-point the issue, so I'm hoping somebody else might have a suggestion of where to look or what might be causing the issue. The relevant symptoms and characteristics: Unresponsiveness occurs after user is idle for 10 minutes User can still move the mouse pointer around the screen Everything but the mouse appears frozen... mouse clicks have no effect and no applications update their displays, including the Windows 7 desktop I left the task manager up along the with the app overnight so I could see the last task manager image before the screen freezes... the Java app is at normal CPU/Memory usage and total CPU usage is only ~1% After moving the mouse (in other words, the user comes back from being idle), the screen image starts updating again within 30 minutes (this is very hit and miss... sometimes 10 minutes, sometimes no results after two hours) User can CTRL-ALT-DEL to get to Windows 7's CTRL-ALT-DEL screen (after a 30 second pause). User is still able to move mouse pointer, but clicking any of the button options causes the screen to appear to freeze again On some very rare occasions, the system never freezes, and I come back to it in the morning with full responsiveness The Java app automatically stops input scripting in the middle of the night, so Windows 7 detects "real" idleness and turns the monitors into Standby mode... which they successfully come out of upon manually moving the mouse in the morning when I wake up, even though the desktop display still appears frozen Given the symptoms and characteristics of the issue, it's as if the Java app is causing the desktop display of the logged in user to stop updating, including any running applications. Programming concepts and Java packages used: Multi-threading Standard out and err are rerouted to a javax.swing.JTextArea The application uses a Swing GUI awt.Robot (very heavily used) awt.PointerInfo awt.MouseInfo System Specs: Windows 7 Professional Java 1.6.0 u17 In conclusion, I should stress that I'm not looking for any specific solutions, as I'm not asking a very specific question. I'm just wondering if anybody has run into a similar problem when using the Java libraries that I'm using. I would also gladly appreciate any suggestions for things to try to attempt to further pinpoint what is causing my problem. Thanks! Ross PS, I'll post an update/answer if I manage to stumble across anything else while I continue to debug this.

    Read the article

  • NullPointerException when thying to add an object to a PriorityQueue

    - by meagan
    i keep getting a null pointer exception when trying to add an object to a priority queue i initialize the queue: private PriorityQueue<NodeObject> nodes; and here i try to add to it: NodeObject childNode = new NodeObject(child, 1); nodes.add(childNode); why doesn't this work? i know my NodeObject is not null because i create it right before i add it.

    Read the article

  • Moving a unit precisely along a path in x,y coordinates

    - by Adam Eberbach
    I am playing around with a strategy game where squads move around a map. Each turn a certain amount of movement is allocated to a squad and if the squad has a destination the points are applied each turn until the destination is reached. Actual distance is used so if a squad moves one position in the x or y direction it uses one point, but moving diagonally takes ~1.4 points. The squad maintains actual position as float which is then rounded to allow drawing the position on the map. The path is described by touching the squad and dragging to the end position then lifting the pen or finger. (I'm doing this on an iPhone now but Android/Qt/Windows Mobile would work the same) As the pointer moves x, y points are recorded so that the squad gains a list of intermediate destinations on the way to the final destination. I'm finding that the destinations are not evenly spaced but can be further apart depending on the speed of the pointer movement. Following the path is important because obstacles or terrain matter in this game. I'm not trying to remake Flight Control but that's a similar mechanic. Here's what I've been doing, but it just seems too complicated (pseudocode): getDestination() { - self.nextDestination = remove_from_array(destinations) - self.gradient = delta y to destination / delta x to destination - self.angle = atan(self.gradient) - self.cosAngle = cos(self.angle) - self.sinAngle = sin(self.angle) } move() { - get movement allocation for this turn - if self.nextDestination not valid - - getNextDestination() - while(nextDestination valid) && (movement allocation remains) { - - find xStep and yStep using movement allocation and sinAngle/cosAngle calculated for current self.nextDestination - - if current position + xStep crosses the destination - - - find x movement remaining after self.nextDestination reached - - - calculate remaining direct path movement allocation (xStep remaining / cosAngle) - - - make self.position equal to self.nextDestination - - else - - - apply xStep and yStep to current position - } - round squad's float coordinates to integer screen coordinates - draw squad image on map } That's simplified of course, stuff like sign needs to be tweaked to ensure movement is in the right direction. If trig is the best way to do it then lookup tables can be used or maybe it doesn't matter on modern devices like it used to. Suggestions for a better way to do it? an update - iPhone has zero issues with trig and tracking tens of positions and tracks implemented as described above and it draws in floats anyway. The Bresenham method is more efficient, trig is more precise. If I was to use integer Bresenham I would want to multiply by ten or so to maintain a little more positional accuracy to benefit collisions/terrain detection.

    Read the article

  • AVAudioPlayer error for Iphone Development

    - by KamalBhr
    Hello , I am developing an iphone application using "AVAudioPlayer" for playing a ".wav" file . For this i am adding header file "#import <AVFoundation/AVAudioPlayer.h>" . But while compiling i am getting error like : ".objc_class_name_AVAudioPlayer", referenced from: literal-pointer@__OBJC@__cls_refs@AVAudioPlayer in WebviewController.o ld: symbol(s) not found collect2: ld returned 1 exit status" . So can you please tell me the solution for this type of error.... Thanks & Regards, KamalBhr "

    Read the article

  • Who use class variables in SOAP calls with Savon?

    - by Steffen Roller
    I'm writing a little client using Ruby and Savon. The interface changed significantly from version 0.7 to 0.8.x. All my calls don't work anymore :-(. How can I pass on a local member variable. Please see the example, @userName and @userPassword are not defined within the block. begin @response = @authentication_svc.request :wsdl, "AuthenticateUser" do http.headers["SOAPAction"] = "AuthenticateUser" soap.body = "#{@userName}#{@passwd}" end rescue Savon::SOAP::Fault = e @last_soap_error = e.message end

    Read the article

< Previous Page | 136 137 138 139 140 141 142 143 144 145 146 147  | Next Page >