CODEWITHSUNDEEP
delphiscreenshotdesktoppascallazarus
andyADD
andyADD

Reputation: 610

Resize image in lazarus or delphi?

I am currently making a desktop screenshot in pascal using lazarus, I have the screenshot working but it only shows the top left of the desktop. I have it set to display smaller image of the desktop on a TImage. I tried using MyBitmap.width := Round(370) and MyBitmap.Height := Round(240);

But those did not work.

unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ExtCtrls,
  StdCtrls, LCLIntf, LCLType;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Image1: TImage;
    procedure Button1Click(Sender: TObject);

  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }



procedure TForm1.Button1Click(Sender: TObject);

  var
    MyBitmap : Tbitmap;
    ScreenDC: HDC;


begin


  try
  MyBitmap := TBitmap.Create;
  ScreenDC := GetDC(0);
  MyBitmap.LoadFromDevice(ScreenDC);
  MyBitmap.Width := Round(370);
  Mybitmap.Height := Round(240);
  ReleaseDC(0, ScreenDC);
  Image1.Picture.Bitmap.Assign(MyBitmap);
  finally
    MyBitmap.free;
  end;





end;

end.

Upvotes: 1

Views: 6602

Answers (1)

bummi
bummi

Reputation: 27377

Replace LoadFromDevice with

MyBitmap.SetSize(370, 240); 
StretchBlt(MyBitmap.Canvas.Handle, //destination HDC
  0, 0, 370, 240, // destination size
  ScreenDC, //source HDC
  0, 0, Screen.Width, Screen.Height, // source size
  SrcCopy 
  );

Setting a smaller size on an existing Bitmap will just crop it.
Your intention is to scale the bitmap.

The StretchBlt function copies a bitmap from a source rectangle into a destination rectangle, stretching or compressing the bitmap to fit the dimensions of the destination rectangle, if necessary. The system stretches or compresses the bitmap according to the stretching mode currently set in the destination device context.

Upvotes: 4

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