本例效果圖:
代碼文件:unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
CheckBox1: TCheckBox;
procedure FormCreate(Sender: TObject);
procedure FormPaint(Sender: TObject);
procedure CheckBox1Click(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
const
{一般模式}
ColorMatrix1: TColorMatrix = (
(1.0, 0.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0, 0.0),
(0.0, 0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 0.0, 1.0, 0.0),
(0.0, 0.0, 0.0, 0.0, 1.0));
{灰度模式}
ColorMatrix2: TColorMatrix = (
(0.3, 0.3, 0.3, 0.0, 0.0),
(0.59, 0.59, 0.59, 0.0, 0.0),
(0.11, 0.11, 0.11, 0.0, 0.0),
(0.0, 0.0, 0.0, 1.0, 0.0),
(0.0, 0.0, 0.0, 0.0, 1.0));
procedure TForm1.FormCreate(Sender: TObject);
begin
CheckBox1.Caption := '轉為灰度';
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g: TGPGraphics;
img: TGPImage;
ImageAttributes: TGPImageAttributes;
begin
g := TGPGraphics.Create(Canvas.Handle);
img := TGPImage.Create('c:\temp\test.png');
ImageAttributes := TGPImageAttributes.Create;
if CheckBox1.Checked then
ImageAttributes.SetColorMatrix(ColorMatrix2)
else
ImageAttributes.SetColorMatrix(ColorMatrix1);
g.DrawImage(img,
MakeRect(4, 4, img.GetWidth, img.GetHeight),
0,
0,
img.GetWidth,
img.GetHeight,
UnitPixel,
ImageAttributes
);
ImageAttributes.Free;
img.Free;
g.Free;
end;
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
Repaint;
end;
end.
窗體文件:object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 216
ClientWidth = 269
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesktopCenter
OnCreate = FormCreate
OnPaint = FormPaint
PixelsPerInch = 96
TextHeight = 13
object CheckBox1: TCheckBox
Left = 183
Top = 191
Width = 79
Height = 17
Caption = 'CheckBox1'
TabOrder = 0
OnClick = CheckBox1Click
end
end
