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