Cannot select bitmap to DC

ok, here is the problem, I cannot get a bitmap to be selected to a DC, my code is as follows:

Code:

---


#include <windows.h>
#include "resource.h"

#define CX_BITMAP 16
#define CY_BITMAP 16

char szAppName[] = TEXT("Bitmap test");
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
HINSTANCE hInst;


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
        HWND hwnd;
        MSG msg;
        WNDCLASS wndclass;

        hInst = hInstance;
        GreenLight= LoadBitmap(hInst,TEXT("GreenLight"));
        wndclass.style = CS_HREDRAW | CS_VREDRAW;
        wndclass.lpfnWndProc = WndProc;
        wndclass.cbClsExtra = 0;
        wndclass.cbWndExtra = 0;
        wndclass.hInstance = hInstance;
        wndclass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
        wndclass.hCursor = LoadCursor(NULL,IDC_ARROW);
        wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
        wndclass.lpszMenuName = NULL;
        wndclass.lpszClassName = szAppName;

        if (!RegisterClass(&wndclass))
        {
                return 0;
        }
       
    hwnd = CreateWindow(szAppName, TEXT("Basic Windows"),
                WS_OVERLAPPEDWINDOW,
                CW_USEDEFAULT,CW_USEDEFAULT,
                CW_USEDEFAULT,CW_USEDEFAULT,
                NULL,NULL,hInstance,NULL);

        if (!hwnd)
                return 0;

        ShowWindow (hwnd,iCmdShow);
        UpdateWindow(hwnd);

        while(GetMessage (&msg,NULL,0,0))
        {
                TranslateMessage (&msg);
                DispatchMessage (&msg);
        }
        return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{

        HBITMAP GreenLight;
        HDC  hdc,hdc1,hdcMem;
        PAINTSTRUCT ps;

        int i;
        switch (message)
        {
        case WM_CREATE:

                GreenLight= LoadBitmap(hInst,TEXT("GreenLight"));

                return 0;
        case WM_PAINT:
                hdc = BeginPaint(hwnd,&ps);

       
                hdcMem = CreateCompatibleDC(hdc);

        if        (!SelectObject(hdcMem,GreenLight))
                MessageBeep(0);
       
                BitBlt(hdc,12,12,CX_BITMAP,CY_BITMAP,hdc,0,0,SRCCOPY);

                EndPaint(hwnd,&ps);
                return 0;

        case WM_DESTROY:
                PostQuitMessage(0);
          return 0;
        }

        return DefWindowProc(hwnd,message,wParam,lParam);
}

---

can anyone help me out?

What value does GreenLight get when you try to load?
If LoadBitamp() returns zero call GetLastError()

What is the resource ID# of the bitmap?

ie

if the bmp's resource is called IDB_BITMAP1

//load from the apps resource file
hBMP = LoadBitmap( hInst, MAKEINTRESOURCE( IDB_BITMAP1 ));

Your paint also has a huge leak in it.

You create a hdc, change its contents then don't DeleteDC() (or even put it back the way you found it). Look up some other threads here or MSDN for DeleteDC() and ReleaseDC().

You should always catch the return from SelectObject(), so you can return this GDI resource back to the HDC prior to freeing the HDC.

Ok, I should of provided more detail. The bitmap loaded into GreenLight is valid, as it works fine if I use it as a background brush, the program even loads up perfectly, it just wont display with the BitBlt command, and i have always had this problem with MSVC 5.0, even using Petzolds as a reference.

Either make GreenLight global or static. Then change the second hdc in BitBlt from hdc to hdcMem.

thanks, the static is what made it work, thanks guys