再学GDI+[64]: 路径画刷(4)

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