Should BeginPaint return a SafeHandle?

[rgwood]

I'm implementing some of the classic examples from Petzold's Programming Windows using CsWin32 (as a learning exercise), and I ran into a minor issue converting the following code from HelloWin.c's WndProc:

Original

     case WM_PAINT:
          hdc = BeginPaint (hwnd, &ps) ;
          
          GetClientRect (hwnd, &rect) ;
          
          DrawText (hdc, TEXT ("Hello, Windows 98!"), -1, &rect,
                    DT_SINGLELINE | DT_CENTER | DT_VCENTER) ;
          
          EndPaint (hwnd, &ps) ;
          return 0 ;

My C# code

case Constants.WM_PAINT:
    hdc = PInvoke.BeginPaint(hwnd, out ps);
    PInvoke.GetClientRect(hwnd, out rect);

    PInvoke.DrawText(hdc, "Hello World", -1, ref rect, DRAW_TEXT_FORMAT.DT_SINGLELINE |  DRAW_TEXT_FORMAT.DT_CENTER | DRAW_TEXT_FORMAT.DT_VCENTER);
    PInvoke.EndPaint(hwnd, ps);
    break;

This fails to compile with CS1503 Argument 1: cannot convert from 'Windows.Win32.Graphics.Gdi.HDC' to 'System.Runtime.InteropServices.SafeHandle'. PInvoke.DrawText() expects a SafeHandle but PInvoke.BeginPaint() does not return a SafeHandle implementation.

I can wrap the HDC in a SafeHandle myself, but I think CsWin32 should be doing this for me (the README says "SafeHandle-types automatically generated"). Is that correct or am I missing something here?

(Version info: CsWin32 0.1.506-beta, Visual Studio 16.11.0 Preview 1.0, .NET 6 Preview 4)

[AArnott]

This is dictated by the metadata. I don't have time to review the case right now, but I'll move to the repo where the decision and change would need to be made.

[mikebattista]

The metadata looks in sync to me. All of these functions return/take an HDC.

Is C#/Win32 projecting them in a way that makes them incompatible?

[AArnott]

@rgwood: there is an overload of DrawText that accepts an HDC parameter. So calling that is one option.
It looks like the friendly overload of BeginPaint that you're calling should be returning a ReleaseDCSafeHandle. I'm not sure why it isn't. I'm investigating.

[AArnott]

Oh! It's because ReleaseDC is a special case in that it takes two parameters. Tracked by #423 in the metadata and microsoft/CsWin32#209 in CsWin32.

[mikebattista]

Duplicate of microsoft/CsWin32#209