再学GDI+[53]: 路径

本例效果图:

代码文件:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, StdCtrls, ExtCtrls;
type
　TForm1 = class(TForm)
　　RadioGroup1: TRadioGroup;
　　procedure FormCreate(Sender: TObject);
　　procedure FormPaint(Sender: TObject);
　　procedure RadioGroup1Click(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI, TypInfo;
procedure TForm1.FormCreate(Sender: TObject);
var
　i: Integer;
begin
　RadioGroup1.Columns := 2;
　RadioGroup1.Caption := '路径填充模式';
　for i := 0 to 1 do
　　RadioGroup1.Items.Add(GetEnumName(TypeInfo(TFillMode), i));
　RadioGroup1.ItemIndex := 0;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　b: TGPBrush;
　p: TGPPen;
　path: TGPGraphicsPath;
　rect: TRect;
begin
　g := TGPGraphics.Create(Canvas.Handle);
　b := TGPHatchBrush.Create(HatchStyleCross, aclSilver, aclKhaki);
　p := TGPPen.Create(aclRed, 1.75);
　path := TGPGraphicsPath.Create;
　rect := Bounds(10, 20, 150, 100);
　path.AddEllipse(MakeRect(rect));
　OffsetRect(rect, 60, 0);
　path.AddEllipse(MakeRect(rect));
　if RadioGroup1.ItemIndex = 1 then path.SetFillMode(FillModeWinding);
　g.FillPath(b, path);
　g.DrawPath(p, path);
　p.Free;
　b.Free;
　path.Free;
　g.Free;
end;
procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
　Repaint;
end;
end.