Could someone look at this simple code and explain why it doesnt work?

16 Nov 2004

      Hi, i found this very simple app which just pops up a
window:

#include <windows.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM
wparam, LPARAM lparam)
{
    switch (msg) {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    default:
        return DefWindowProc(hwnd, msg, wparam,
lparam);
    }
}

int WINAPI WinMain(HINSTANCE instance, HINSTANCE prev,
LPSTR cmdLine, int cmdShow)
{
    WNDCLASSEX class;
    MSG msg;
    HWND window;

    /* this stuff is just boilerplate */
    memset(&class, 0, sizeof(WNDCLASSEX));
    class.cbSize = sizeof(WNDCLASSEX);
    class.hInstance = instance;
    class.lpszClassName = "MainWnd";
    class.lpfnWndProc = WndProc;
    class.hbrBackground = (HBRUSH) COLOR_WINDOW + 1;

    if (!RegisterClassEx(&class)) {
        MessageBox(NULL, "Could not register window
class", "", MB_OK | MB_ICONERROR);
        return 1;
    }

    window = CreateWindowEx(0, "MainWnd", "Main
Window", WS_OVERLAPPEDWINDOW & ~WS_MAXIMIZEBOX,
                            CW_USEDEFAULT,
CW_USEDEFAULT, 200, 150, NULL, NULL, instance, NULL);
    ShowWindow(window, cmdShow);

    /* Every thread that creates a window must pump
the message loop */
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;
}

Now i tried to implement this in a dll (avicap32.dll)
in capCreatecapturewindow like this:

/***********************************************************************
 *             capCreateCaptureWindowW   (AVICAP32.@)
 */
HWND VFWAPI capCreateCaptureWindowW(LPCWSTR
lpszWindowName, DWORD dwStyle, INT x,
                                    INT y, INT nWidth,
INT nHeight, HWND hWnd,
                                    INT nID)
{

HWND ret;
HINSTANCE dummy;

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM
wparam, LPARAM lparam)
{
    switch (msg) {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    default:
        return DefWindowProcW(hwnd, msg, wparam,
lparam);

    }
}

int WINAPI Try(HINSTANCE instance, HINSTANCE prev,
LPSTR cmdLine, int cmdShow)
{
    WNDCLASSEXW class;
    MSG msg;
    HWND window;

    /* this stuff is just boilerplate */
    memset(&class, 0, sizeof(WNDCLASSEXW));
    class.cbSize = sizeof(WNDCLASSEXW);
    class.hInstance = instance;

    dummy=instance;

    class.lpszClassName = "MainWnd";
    class.lpfnWndProc = WndProc;
    class.hbrBackground = (HBRUSH) COLOR_WINDOW + 1;

    if (!RegisterClassExW(&class)) {
        MessageBoxW(NULL, "Could not register window
class", "", MB_OK | MB_ICONERROR);
        return 1;
    }

    window = CreateWindowExW(0, "MainWnd", "Main
Window", WS_OVERLAPPEDWINDOW & ~WS_MAXIMIZEBOX,
                            CW_USEDEFAULT,
CW_USEDEFAULT, 200, 150, NULL, NULL, instance, NULL);

	ret=window;

    ShowWindow(window, cmdShow);

    /* Every thread that creates a window must pump
the message loop */
    while (GetMessageW(&msg, NULL, 0, 0)) {
            TranslateMessage(&msg);
            DispatchMessageW(&msg);}

    return 0;
}

 Try(dummy,NULL,NULL,0);
   return ret;
}

Now when capcreatecapturewindow is called no window
shows up at all. What did i do wrong? Greetings
Robbert

:

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