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

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).

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本例效果图:

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代码文件:

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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:

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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