Delphi realizes the method of screen-cutting _delphi

This paper illustrates the method of Delphi to save the screen. Share to everyone for your reference. The specific analysis is as follows:

This instance implements the interception screen and saves the functionality as a JPEG file format.

Procedure Tform1.screencap (Leftpos,toppos,rightpos,bottompos:integer);
var
 rectwidth,rectheight:integer;
 Sourcedc,destdc,bhandle:integer;
 Bitmap:tbitmap;
 Myjpeg:tjpegimage;
 Stream:tmemorystream;
Begin
 myjpeg:= tjpegimage.create;
 Rectwidth:=rightpos-leftpos;
 Rectheight:=bottompos-toppos;
 Sourcedc:=createdc (' DISPLAY ', ', ', ', ', Nil ');
 Destdc:=createcompatibledc (SOURCEDC);
 Bhandle:=createcompatiblebitmap (Sourcedc,
 rectwidth,rectheight);
 SelectObject (destdc,bhandle);
 BitBlt (Destdc,0,0,rectwidth,rectheight,sourcedc,
 leftpos,toppos,srccopy);
 Bitmap:=tbitmap.create;
 Bitmap.handle:=bhandle;
 Stream: = tmemorystream.create;
 Bitmap.savetostream (Stream);
 Stream.free;
 Try
  myjpeg.assign (Bitmap);
  myjpeg.compressionquality:=70;
  myjpeg.compress;
  Myjpeg.savetofile (' c:myjpegimage.jpg ');
 Finally
  Myjpeg.free;
  Bitmap.free;
  DeleteDC (DESTDC);
  ReleaseDC (BHANDLE,SOURCEDC);
 End;
End

I hope this article will help you with the Delphi program design.