再学 GDI+[82]: TGPImage(2) - GetThumbnailImage - 略缩图

本例效果图:

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代码文件:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs;



type

  TForm1 = class(TForm)

    procedure FormPaint(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



uses GDIPOBJ, GDIPAPI;



procedure TForm1.FormPaint(Sender: TObject);

var

  g: TGPGraphics;

  img,imgSmall: TGPImage;

begin

  g := TGPGraphics.Create(Self.Canvas.Handle);



  img := TGPImage.Create('C:\temp\test.png');



  {如果图像没有携带略缩图, 将缩放生成; 略缩图一般不应超过 120*120}

  imgSmall := img.GetThumbnailImage(32, 32, nil, nil);



  g.DrawImage(img, 0, 0, img.GetWidth, img.GetHeight);

  g.DrawImage(imgSmall, img.GetWidth + 4, 0, imgSmall.GetWidth, imgSmall.GetHeight);



  imgSmall.Free;

  img.Free;

  g.Free;

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 151

  ClientWidth = 230

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

end