再學GDI+[82]: TGPImage(2) - GetThumbnailImage - 略縮圖

本例效果圖:

代碼文件: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');
　{如果圖像沒有攜帶略縮圖, 將縮放生成; 略縮圖一般不應超過 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.

窗體文件: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