Question

im working on an application using delphi 6, where im trying to integrate camera into the existing application, the camera code displays the captured frames onto a Tpanel, in my application i need to display the captured frame on Tpaintbox ( i am not the original coder),

this is a code sample from the

  procedure TFrameThreadX.DrawFrame;
    var
    hdc:THandle; 
     begin
       
       //do processing
      .
      . 
       hdc := GetDC( ViewForm.ViewPanel.Handle );
       SetStretchBltMode(hdc,COLORONCOLOR);
       StretchDIBits(hdc,0,0,nW,nH,0,0,ScW,ScH,DibPixels,TBitMapInfo((@FDib)^),DIB_RGB_COLORS,SRCCOPY);
       ReleaseDC( ViewForm.ViewPanel.Handle, hdc );


     //do processing
    end;

here is get the Tpanel handle as 87248682 from this

  hdc := GetDC( ViewForm.ViewPanel.Handle );

so when i try to use Tpaintbox in the code like this

       hdc := GetDC( ViewForm.PaintBox1.Canvas.Handle);

The result is 0,

so the camera frames are not displayed..

so i tried this

using the GetDC and GetWindowDC but in both the cases the result of the functions is 0 for the handle,

my code

   var
     hdc  : THandle;
     begin
       hdc := GetDC(Panel1.Handle);
       Label1.Caption:=inttostr(hdc);
       hdc := GetDC(Image1.Canvas.Handle);
       Label2.Caption:=inttostr(hdc);
       hdc := GetDC(PaintBox1.Canvas.Handle);
       Label3.Caption:=inttostr(hdc);
     end;

And for GetWindowDC

    var
     hdc  : THandle;
     begin
     hdc := GetWindowDC(Panel1.Handle);
     Label4.Caption:=inttostr(hdc);
     hdc := GetWindowDC(Image1.Canvas.Handle);
     Label5.Caption:=inttostr(hdc);
     hdc := GetWindowDC(PaintBox1.Canvas.Handle);
     Label6.Caption:=inttostr(hdc);
    end;

So please tell me how to get the Tpaint handle?

Answer 1

Canvas.Handle is the DC handle you’re looking for, so HDC := PaintBox1.Canvas.Handle