再学 GDI+[81]: TGPImage(1) - 显示图像

已知 GDI+ 可以支持的图像格式: BMP、JPEG、GIF、TIFF、PNG、ICO、WMF、EMF

---

TGPGraphics.DrawImage 函数有太多重载了, 一起列在这吧:

---

function DrawImage(image: TGPImage; const point: TGPPointF): TStatus; overload;



function DrawImage(image: TGPImage; x, y: Single): TStatus; overload;



function DrawImage(image: TGPImage; const rect: TGPRectF): TStatus; overload;



function DrawImage(image: TGPImage; x, y, width, height: Single): TStatus; overload;



function DrawImage(image: TGPImage; const point: TGPPoint): TStatus; overload;



function DrawImage(image: TGPImage; x, y: Integer): TStatus; overload;



function DrawImage(image: TGPImage; const rect: TGPRect): TStatus; overload;



function DrawImage(image: TGPImage; x, y, width, height: Integer): TStatus; overload;



function DrawImage(image: TGPImage; destPoints: PGPPointF; count: Integer): TStatus; overload;



function DrawImage(image: TGPImage; destPoints: PGPPoint; count: Integer): TStatus; overload;



function DrawImage(

  image: TGPImage;

  x, y, srcx, srcy, srcwidth, srcheight: Single;

  srcUnit: TUnit

): TStatus; overload;



function DrawImage(image: TGPImage; 

  const destRect: TGPRectF;

  srcx, srcy, srcwidth, srcheight: Single;

  srcUnit: TUnit;

  imageAttributes: TGPImageAttributes = nil;

  callback: DrawImageAbort = nil;

  callbackData: Pointer = nil

): TStatus; overload;



function DrawImage(

  image: TGPImage;

  destPoints: PGPPointF;

  count: Integer;

  srcx, srcy, srcwidth, srcheight: Single;

  srcUnit: TUnit;

  imageAttributes: TGPImageAttributes = nil;

  callback: DrawImageAbort = nil;

  callbackData: Pointer = nil

): TStatus; overload;



function DrawImage(image: TGPImage; 

  x, y, srcx, srcy, srcwidth, srcheight: Integer;

  srcUnit: TUnit

): TStatus; overload;



function DrawImage(

  image: TGPImage;

  const destRect: TGPRect;

  srcx, srcy, srcwidth, srcheight: Integer;

  srcUnit: TUnit;

  imageAttributes: TGPImageAttributes = nil;

  callback: DrawImageAbort = nil;

  callbackData: Pointer = nil

): TStatus; overload;



function DrawImage(

  image: TGPImage;

  destPoints: PGPPoint;

  count, srcx, srcy, srcwidth, srcheight: Integer;

  srcUnit: TUnit;

  imageAttributes: TGPImageAttributes = nil;

  callback: DrawImageAbort = nil;

  callbackData: Pointer = nil

): TStatus; overload;


 
   

本例效果图:

---

代码文件:

---

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: TGPImage;

begin

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



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



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



  img.Free;

  g.Free;

end;



end.


 
   

窗体文件:

---

object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 290

  ClientWidth = 355

  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