C++ Debugging LoadImage() and Skipping Breakpoints

Question

I am trying to find out why I cannot load an image from a resource.

Images work when lpszName is filename, when changed to resource they do not.
Images are created the same way (Can be interchanged, same problem)
Images are located inside the Resource and Resource.rc files.

The code:

LRESULT CALLBACK WndProc(HWND hWinMain, UINT message, WPARAM wParam, LPARAM lParam)
{
    DWORD
        lastError;
    static HDC
        hdcFromResource,
        hdcFromFilename;
    HBITMAP
        hFromResource,
        hFromResourcePrevious,
        hFromFilename,
        hFromFilenamePrevious;
    HDC 
        hdc;
    PAINTSTRUCT ps;
    switch (message)
    {
    case WM_CREATE:
        hdc = GetDC(hWinMain);
        hdcFromFilename = CreateCompatibleDC(hdc);
        hdcFromResource = CreateCompatibleDC(hdc);
        ReleaseDC(hWinMain, hdc);
        hFromFilename = (HBITMAP)LoadImageW(NULL, (L"filename.bmp"), IMAGE_BITMAP, 100, 100, LR_LOADFROMFILE);
        if (!hFromFilename)
        {
            // ERROR HANDELING
        }
        hFromFilenamePrevious = (HBITMAP)SelectObject(hdcFromFilename, hFromFilename);
        DeleteObject(hFromFilename);
        DeleteObject(hFromFilenamePrevious);
        hFromResource = (HBITMAP)LoadImageW(NULL, MAKEINTRESOURCEW(IDB_RESOURCE), IMAGE_BITMAP, 100, 100, LR_CREATEDIBSECTION | LR_LOADFROMFILE);   
        lastError = GetLastError();
        lastError;
        hFromResourcePrevious = (HBITMAP)SelectObject(hdcFromResource, hFromResource);
        DeleteObject(hFromResource);
        DeleteObject(hFromResourcePrevious);
        return 0;
    case WM_PAINT:
        hdc = BeginPaint(hWinMain, &ps);
        BitBlt(hdc, 0, 0, 100, 100, hdcFromFilename, 0, 0, SRCCOPY);
        BitBlt(hdc, 100, 100, 100, 100, hdcFromResource, 0, 0, SRCCOPY);
        EndPaint(hWinMain, &ps);
        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hWinMain, message, wParam, lParam);
}

The if(!hFromFilename) is never triggered whether the image loaded or not.
None of the breakpoints after the failed image load breaks (breakpoints through WM_CREATE, other breakpoints in other functions work as normal)
I am unsure how to easily read GetLastError without a breakpoint.

Resource.h #define IDB_RESOURCE 101

Resource.rc #define IDB_RESOURCE BITMAP DISCARDABLE "resource.bmp"

`LoadImageW(NULL, MAKEINTRESOURCEW(IDB_RESOURCE), IMAGE_BITMAP, 100, 100, LR_CREATEDIBSECTION | LR_LOADFROMFILE);` `LR_LOADFROMFILE` is for stand-alone image files, not embedded resources, so this needs to be removed. hInst should not be NULL for your own resources -- if these resources are in your exe, get hInst by calling `GetModuleHandle(NULL)` — Christopher Oicles, Mar 04 '16 at 23:27
@HansPassant IDB_RESOURCE is "resource.bmp", there is no resource ID for "filename.bmp". — Built on Sin, Mar 05 '16 at 00:30

Built on Sin · Answer 1 · 2016-03-05T10:29:17.043

The problem as answered by Christopher Oicles was that LR_LOADFROMFILE is not needed.

May be useful for others:

To load an image from filename (Using LoadImage()) example:

LoadImage(
NULL,                           // NULL for load image via filename
L("directory\\filename.bmp"),   // String to filename
IMAGE_BITMAP                    // Flag for loading bitmap
0,                              // 0 Should use the images actual width
0,                              // 0 Should use the images actual height
LR_LOADFROMFILE                 // Flag for loading from file
);

To load an image from resource (Using LoadImage()) example:

LoadImage(
hInstance,                      // hInstance to the file containing the resource
MAKEINTRESOURCE(IDB_RESOURCE),  // Resource definition
IMAGE_BITMAP                    // Flag for loading bitmap
0,                              // 0 Should use the images actual width
0,                              // 0 Should use the images actual height
LR_CREATEDIBSECTION             // Do not use LR_LOADFROMFILE if it is a resource
);

Resourcefile.h

#define IDB_RESOURCE 101                         // Resource ID, and number

Resourcescript.rc

#include "Resourcefile.h"
IDB_RESOURCE BITMAP "directory\\filename.bmp"    // Resource ID, type, and filename

Thank you.

C++ Debugging LoadImage() and Skipping Breakpoints

1 Answers1