Author: Jonas Bilinkevicius

How can I manually call the "hardcopy" function (PrtScr) or how can I trick it by 
sending the keycode for PrtScr?

Answer:

1   procedure SimulateKeystroke(Key: byte; extra: DWORD);
2   begin
3     keybd_event(Key, extra, 0, 0);
4     keybd_event(Key, extra, KEYEVENTF_KEYUP, 0);
5   end;
6   
7   procedure TForm1.Button2Click(Sender: TObject);
8   begin
9     {Capture the entire screen to the clipboard by simulating pressing the 
10  PrintScreen key}
11    SimulateKeystroke(VK_SNAPSHOT, 0);
12  end;
13  
14  procedure TForm1.Button3Click(Sender: TObject);
15  begin
16    {Capture the active window to the clipboard by simulating pressing the 
17  PrintScreen key}
18    SimulateKeystroke(VK_SNAPSHOT, 1);
19  end;