Question

How to convert HICON to HBITMAP in VC++?

I know this is an FAQ but all the solutions I’ve found on Google don’t work. What I need is a function which takes a parameter HICON and returns HBITMAP.

Greatest if possible to make conversion to 32-bit bitmap even the icon is 24-bit, 16-bit or 8-bit.

This is the code, I don’t know where it goes wrong:

HBITMAP icon_to_bitmap(HICON Icon_Handle) {
  HDC Screen_Handle = GetDC(NULL);
  HDC Device_Handle = CreateCompatibleDC(Screen_Handle);

  HBITMAP Bitmap_Handle = 
  CreateCompatibleBitmap(Device_Handle,GetSystemMetrics(SM_CXICON),
  GetSystemMetrics(SM_CYICON));

  HBITMAP Old_Bitmap = (HBITMAP)SelectObject(Device_Handle,Bitmap_Handle);
  DrawIcon(Device_Handle, 0,0, Icon_Handle);
  SelectObject(Device_Handle,Old_Bitmap);

  DeleteDC(Device_Handle);
  ReleaseDC(NULL,Screen_Handle);
  return Bitmap_Handle;
}

Answer 1

I don’t have code readily available to share, but I think this is pretty easy. You have to create the HBITMAP, create a device context, select the bitmap into the DC (this will make the bitmap the drawing area for this DC). Finally call the DrawIcon() function to draw your icon on this DC. After that detach the bitmap from the DC and destroy the DC. Your bitmap now should be ready to go.

Update after looking at your code:

I believe the problem is in the createCompatibleBitmap call. You are asking for a bitmap compatible with the memory DC, but memory DCs start with a 1 bit/pixel bitmap selected into them. Try asking for a bitmap compatible with the screen DC instead.

Update 2: you may want to look at this question as it seems related to your problem.