GdiPlus[19]: IGPPathGradientBrush 之 SetCenterPoint

测试效果图:

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测试代码:

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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);

    procedure FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



uses GdiPlus, GdiPlusHelpers;



var

  Pt: TGPPointF;



procedure TForm1.FormPaint(Sender: TObject);

var

  Brush: IGPPathGradientBrush;

  Rect: TGPRect;

  Path: IGPGraphicsPath;

begin

  Rect.Initialize(10, 10, 200, 150);

  Path := TGPGraphicsPath.Create;

  Path.AddEllipse(Rect);



  Brush := TGPPathGradientBrush.Create(Path);

  Brush.CenterColor := $FF00FF00;

  Brush.SetSurroundColors([$FF000000]);



  Brush.SetCenterPoint(Pt);



  Canvas.ToGPGraphics.FillEllipse(Brush, Rect);

  Canvas.ToGPGraphics.DrawRectangle(TGPPen.Create($FFFF0000), Pt.X-3, Pt.Y-3, 6, 6);

end;



procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

begin

  Pt.X := X;

  Pt.Y := Y;

  Repaint;

end;



end.