Delphi图象截取编程示例(4)

(六)TMainForm的 (抓图)Action 事件
1)全屏抓图
[Capture Desktop]  Action 事件
procedure TMainForm.cptDesktopExecute(Sender: TObject);
begin
  inc(CaptureNum,1);
  Application.Minimize ;  //窗体最小化
  Delay(500);             //最小化后延时，为了全屏抓图不把自身抓进图中
  FileName:='Capture'+IntToStr(CaptureNum)+'.bmp';
  FileName:=DefaultDirectory+FileName;
  CreateMDIChild(FileName,true);
  StatusBar.SimpleText := FileName;
  with ActiveMDIChild as TMDIChild do begin
    Image1.Picture.Bitmap := CaptureScreen;         //抓图
    HorzScrollBar.Range := Image1.Picture.Width;
    VertScrollBar.Range := Image1.Picture.Height;
  end;
  Child.Image1.Hint := 'Height:'+intToStr(child.Image1.Picture.Height)+'pixels'
                     + ' Width:'+intToStr(child.Image1.Picture.Width)+'pixels';
  application.Restore ;
end;

2)区域抓图
   抓取区域图片，即要用到一个新的Form1，参见《Delphi图象截取编程示例(6)》  .
   在Main单元implementation的uses中添加Capture1。
   在Main单元添加私有过程CaptureArea :
procedure TMainForm.CaptureArea;
begin
  with TForm1.Create(Application) do
  try
    if ShowModal=mrOK then
    with fRect do begin
      if (Right>Left)and(Bottom>Top) then begin
        Delay(400);
        ABitmap:=TBitmap.Create;
        ABitmap.Assign(CaptureScreenRect(fRect));
        Child.Image1.Picture.Bitmap:=ABitmap;
        Child.ClientWidth := Child.Image1.Picture.Width ;
        Child.ClientHeight:= Child.Image1.Picture.Height;
        Child.HorzScrollBar.Range:=Child.Image1.Picture.Width ;
        Child.VertScrollBar.Range:=Child.Image1.Picture.Height;
        ABitmap.Free ;
      end else begin
        MessageDlg('选择图片区域错误，请重新选择！',mtInformation,[mbOK],0);
        Child.Close ;
        Form1.Free ;
        exit;
      end;
    end;
  finally
    Free;
  end;
end;

[Capture Area]区域抓图的Action 事件
procedure TMainForm.cptAreaExecute(Sender: TObject);
begin
  Inc(CaptureNum,1);
  Application.Minimize ;
  Delay(500);
  FileName:='Capture'+IntToStr(CaptureNum)+'.bmp';
  FileName:=DefaultDirectory+FileName;
  { Create MDI Child Window }
  CreateMDIChild(FileName,true);
  StatusBar.SimpleText := FileName;

  { Capture Area of screen }
  CaptureArea;
  Child.Image1.Hint := 'Height:'+intToStr(child.Image1.Picture.Height)+'pixels'
                     + ' Width:'+intToStr(child.Image1.Picture.Width)+'pixels';
  application.Restore ;
end;

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