Tony,
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I’ve written this:
LoadBitmapW(ghInstance, MAKEINTRESOURCE(IDR_BMP_ONE));
GetDlgItem(hwndDlg, ID_BUTONE);
SendMessage(HWND(ID_BUTONE), BM_SETIMAGE, IMAGE_BITMAP,IDR_BMP_ONE);
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Here is the corrected code. Why are you using LoadBitmapW() ? If you are compiling UNICODE the compiler will sort out which API's to use, weather UNICODE or not.
HBITMAP hBitmap = LoadBitmap(ghInstance, MAKEINTRESOURCE(IDR_BMP_ONE));
HWND hBut = GetDlgItem(hwndDlg, ID_BUTONE);
SendMessage(hBut, (UINT)BM_SETIMAGE, (WPARAM)IMAGE_BITMAP, (LPARAM)hBitmap);
Try to understand what's required. For example you had put the identifier IDR_BMP_ONE instead of the handle to the bitmap that is returned from LoadBitmap. Also ID_BUTONE in the SendMessage API where it required the handle to the button not an identifier.
Here, you are trying to cast an int (ID_BUTONE), to a HWND
SendMessage(HWND(ID_BUTONE), BM_SETIMAGE, IMAGE_BITMAP,IDR_BMP_ONE);
Plus, casting is this way, (HWND)type not the way you had it.
John