Screenshot: capture the current program interface and save it to the BMP image.

Directly run the Code:

 

 unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,Clipbrd;

type
  TForm1 = class(TForm)
    btn1: TButton;
    dlgSave1: TSaveDialog;
procedure btn1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
var
  bmp:TBitmap;
  MyRect:TRect;
  Myrect2:TRect;
  canvas:TCanvas;
  DC:HDC;
  b:TPoint;
  aa:TPoint;
begin
  ShowMessage('---------------');
  bmp := TBitmap.Create;
  bmp.Width := Form1.Width;
  bmp.Height := form1.Height;
  MyRect := Rect(Form1.Left,Form1.Top,bmp.Width+Form1.Left,bmp.height+Form1.Top);
  Myrect2 :=Rect(0,0,bmp.Width,bmp.height);
  DC := GetDC(0);
  Canvas := TCanvas.Create;
  Canvas.Handle := DC;
  bmp.Canvas.CopyRect(MyRect2,Canvas,MyRect);
  Clipboard.Assign(bmp);
if dlgSave1.Execute then
    bmp.SaveToFile(dlgSave1.FileName + '.bmp');
  Canvas.Free;
  ReleaseDC(0,DC);
  bmp.Free;


end;

end.