再学GDI+[64]: 路径画刷（4） - 还是 SetCenterColor、SetSurroundColors

再学GDI+[64]: 路径画刷（4） - 还是 SetCenterColor、SetSurroundColors2012-05-14 cnblogs 万一在本例中没有指定 CenterColor, 将默认白色;

SurroundColors 原来是对应路径中的点（但按下面的做法在椭圆里不灵）.

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
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormPaint（Sender: TObject）;
const
 ColorArr: array[0..3] of TGPColor = （$FFFF0000, $FF00FF00, $FF0000FF, $FFFFFF00）;
var
 rt: TRect;
 pts: array of TGPPoint;
 g: TGPGraphics;
 path1, path2: TGPGraphicsPath;
 pb1,pb2: TGPPathGradientBrush;
 num: Integer;
begin
 rt := Bounds（10, 10, 150, 150）;
 g := TGPGraphics.Create（Canvas.Handle）;
 {矩形路径}
 path1 := TGPGraphicsPath.Create;
 path1.AddRectangle（MakeRect（rt））;
 pb1 := TGPPathGradientBrush.Create（path1）;
 num := 4;
 pb1.SetSurroundColors（PARGB（@ColorArr）, num）;
 g.FillPath（pb1, path1）;
 {三角形路径}
 OffsetRect（rt, 160, 0）;
 SetLength（pts, 3）;
 pts[0] := MakePoint（rt.Left + （rt.Right-rt.Left） div 2, rt.Top）;
 pts[1] := MakePoint（rt.Left, rt.Bottom）;
 pts[2] := TGPPoint（rt.BottomRight）;
 path2 := TGPGraphicsPath.Create;
 path2.AddPolygon（PGPPoint（pts）, Length（pts））;
 pb2 := TGPPathGradientBrush.Create（path2）;
 num := 3;
 pb2.SetSurroundColors（PARGB（@ColorArr）, num）;
 g.FillPath（pb2, path2）;
 pb1.Free;
 pb2.Free;
 path1.Free;
 path2.Free;
 g.Free;
end;
end.

窗体文件:

object Form1: TForm1
 Left = 0
 Top = 0
 Caption = "Form1"
 ClientHeight = 172
 ClientWidth = 327
 Color = clBtnFace
 Font.Charset = DEFAULT_CHARSET
 Font.Color = clWindowText
 Font.Height = -11
 Font.Name = "Tahoma"
 Font.Style = []
 OldCreateOrder = False
 Position = poDesktopCenter
 OnPaint = FormPaint
 PixelsPerInch = 96
 TextHeight = 13
end