Window does not work.

This is a discussion on Window does not work. within the Windows Programming forums, part of the Platform Specific Boards category; I am creating a window with the Dev-C++ compiler. I know that the code for this comes built in but ...

  1. #1
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    Window does not work.

    I am creating a window with the Dev-C++ compiler. I know that the code for this comes built in but I learn better if I type it out. The thing is, after I copied it and created a new project, deleted the code and inserted my own....it compiled but the window did not show up. Is this normal? Here is the code I copied:
    Code:
    #include <windows.h>
    
    /* Declare windows procedure */
    LRESULT CALLBACK WindowProcedure ( HWND, UINT, WPARAM, LPARAM);
    
    /* Make the class name into a global variable */
    char szClassName[] = "WindowsApp";
    
    int WINAPI WinMain (HINSTANCE hThisInstance,
                        HINSTANCE hPrevInstance,
                        LPSTR lpszArgument,
                        int nFunsterStil)
    {
      HWND hwnd;        /* This is the handle for our window */
      MSG messages;     /* Here messages to the application are saved */
      WNDCLASSEX wincl; /* Data structure for windows class */
      
      /* The Windows Sturcture */
      wincl.hInstance = hThisInstance;
      wincl.lpszClassName = szClassName;      
      wincl.lpfnWndProc = WindowProcedure;    /* This function is called by windows */
      wincl.style = CS_DBLCLKS;               /* Catch double clicks */
      wincl.cbSize = sizeof (WNDCLASSEX);
      
      /* Use default icon and mouse-pointer */
      wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
      wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
      wincl.lpszMenuName = NULL;                       /* No Menu */
      wincl.cbClsExtra = 0;                            /* No extra bytes after the windows class */
      wincl.cbWndExtra = 0;                            /* Structure or the window instance */
      
      /* Use windows's default background color */
      wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
      
      /* Register the window class, if it fails quit the program */
      if (!RegisterClassEx (&wincl))
      return 0;
      
      /* The class is registered, let's create the program */
      hwnd = CreateWindowEx (
             0,                         /* Extended possibilites for variation */
             szClassName,               /* Classname */
             "My Cute Window",             /* Window Title */
             WS_OVERLAPPEDWINDOW,       /* default window */
             CW_USEDEFAULT,             /* Windows decides the position */
             CW_USEDEFAULT,             /* where the program is at on the screen */
             544,                       /* Program width */
             375,                       /* the height in pixels */
             HWND_DESKTOP,              /* The window is a child window of the desktop */
             NULL,                      /* No Menu */
             hThisInstance,             /* Program Instance handler */
             NULL                       /* No Window creation data */
             );
             
      /* Make the window visible on the screen */
      ShowWindow (hwnd, nFunsterStil);
      
      /* Run the message loop. It will run until GetMessage() return 0 */
      while (GetMessage (&messages, NULL, 0,0))
      {
            /* Translate virtual-key message into character messages */
            TranslateMessage(&messages);
            /* Send message to WindowsProcedure */
            DispatchMessage (&messages);
      }
      
      /* The program return-value is 0  -  The value that PostQuitMessage() gave */
      return messages.wParam;
    }
    
    /* This function is called by the Windows function DispatchMessage() */
    
    LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
            switch (message)                          /* handle the messages */
            {
                   case WM_DESTROY:
                        PostQuitMessage(0);           /* send a WM_QUIT to the message queue */
                        break;
                   default:                           /* For messages we done deal with */
                           return DefWindowProc (hwnd, message, wParam, lParam);
            }
       return 0;
    }
    Last edited by RealityFusion; 10-04-2005 at 12:03 PM.
    Knowledge is power and I want it all

    -0RealityFusion0-

  2. #2
    Even death may die... Dante Shamest's Avatar
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    Malaysia
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    RegisterClassEx is failing because you didn't initialize the hCursor member of WNDCLASSEX. Add this line.

    Code:
    wincl.hCursor = LoadCursor(NULL,IDC_ARROW);
    When using a struct, it's usually a good idea to make sure you initialize the struct to 0.

    Code:
    WNDCLASSEX wincl = {0};
    Edit: Changed hThisInstance to NULL.
    Last edited by Dante Shamest; 10-04-2005 at 12:42 PM.

  3. #3
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    Well I added the code and it still didn't work. After playing around with it for a while I finally figured out why it wasn't working and why I was getting the Permission denied error. When I saved the project I overwrote a previous project. So this time I just saved it and renamed it something unique and it worked fine. Does anyone know why, when you save over a project, you get the permission denied error?!?!
    Knowledge is power and I want it all

    -0RealityFusion0-

  4. #4
    Reverse Engineer maxorator's Avatar
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    Well, I use Dev-C++ too, but I don't have problems with overwriting projects...

  5. #5
    Registered User Queatrix's Avatar
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    Sometimes if your program didn't close properly, (In the sence as in, the widow disappeared but the program for some reason was still running in the bg.) Then when Dev-C++ tries to write over the running application, it can't, and gets the "permission denied" error.

  6. #6
    Reverse Engineer maxorator's Avatar
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    Well, for me, Dev-C++ doesn't let me press compile at all, when my program is still running in bg. Then I close my program from the task manager.

  7. #7
    Registered User Queatrix's Avatar
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    >> Well, for me, Dev-C++ doesn't let me press compile at all,

    It only does that if you started the program through Dev-C++.
    It won't if you start it through something else.

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