再学GDI+[48]: 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;
type
　TForm1 = class(TForm)
　　CheckBox1: TCheckBox;
　　CheckBox2: TCheckBox;
　　procedure FormCreate(Sender: TObject);
　　procedure FormPaint(Sender: TObject);
　　procedure CheckBox1Click(Sender: TObject);
　　procedure CheckBox2Click(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormCreate(Sender: TObject);
begin
　CheckBox1.Caption := 'CloseFigure';
　CheckBox2.Caption := 'CloseAllFigures';
end;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　path: TGPGraphicsPath;
　p: TGPPen;
　b: TGPBrush;
　pts1,pts2,pts3: array[0..2] of TGPPoint;
　i: Integer;
begin
　pts1[0] := MakePoint(0, 30);
　pts1[1] := MakePoint(30, 0);
　pts1[2] := MakePoint(60, 30);
　for i := 0 to Length(pts1) do
　begin
　　pts2[i].X := pts1[i].X + 80;
　　pts2[i].Y := pts1[i].Y + 20;
　　pts3[i].X := pts2[i].X + 80;
　　pts3[i].Y := pts2[i].Y + 20;
　end;
　g := TGPGraphics.Create(Canvas.Handle);
　path := TGPGraphicsPath.Create;
　path.StartFigure;
　path.AddLines(PGPPoint(@pts1), Length(pts1));
　path.StartFigure;
　path.AddLines(PGPPoint(@pts2), Length(pts2));
　path.StartFigure;
　path.AddLines(PGPPoint(@pts3), Length(pts3));
　if CheckBox1.Checked then path.CloseFigure;
　if CheckBox2.Checked then path.CloseAllFigures;
　p := TGPPen.Create(aclRed, 2);
　b := TGPSolidBrush.Create(aclYellow);
　g.DrawPath(p, path);
　b.Free;
　p.Free;
　path.Free;
　g.Free;
end;
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
　Repaint;
end;
procedure TForm1.CheckBox2Click(Sender: TObject);
begin
　Repaint;
end;
end.