本例效果图:
![](https://www.cnblogs.com/images/cnblogs_com/del/138617/o_86197.gif)
代码文件:
![](https://www.cnblogs.com/images/cnblogs_com/del/138617/o_86197.gif)
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; var pts: array[0..6] of TGPPoint; procedure TForm1.FormCreate(Sender: TObject); begin pts[0].X := 10; pts[0].Y := 50; pts[1].X := 40; pts[1].Y := 90; pts[2].X := 80; pts[2].Y := 10; pts[3].X := 110; pts[3].Y := 50; pts[4].X := 140; pts[4].Y := 10; pts[5].X := 180; pts[5].Y := 90; pts[6].X := 210; pts[6].Y := 50; CheckBox1.Caption := '翻转路径中的点'; CheckBox2.Caption := '清空路径中的点'; end; procedure TForm1.FormPaint(Sender: TObject); var g: TGPGraphics; p: TGPPen; path: TGPGraphicsPath; PathPts: array of TGPPoint; i: Integer; begin g := TGPGraphics.Create(Canvas.Handle); p := TGPPen.Create(aclRed, 2); path := TGPGraphicsPath.Create; path.AddBeziers(PGPPoint(@pts), Length(pts)); if CheckBox1.Checked then path.Reverse; if CheckBox2.Checked then path.Reset; {Reset 时, 会清空 PathPoints 和 PathTypes 数组并将 FillMode 设置为 FillModeAlternate} SetLength(PathPts, path.GetPointCount); path.GetPathPoints(PGPPoint(PathPts), Length(PathPts)); Canvas.Pen.Color := clGray; for i := Low(PathPts) to High(PathPts) do Canvas.TextOut(PathPts[i].X, PathPts[i].Y, IntToStr(i+1)); g.DrawPath(p, path); path.Free; p.Free; g.Free; end; procedure TForm1.CheckBox1Click(Sender: TObject); begin Repaint; end; procedure TForm1.CheckBox2Click(Sender: TObject); begin Repaint; end; end.窗体文件:
object Form1: TForm1 Left = 0 Top = 0 Caption = 'Form1' ClientHeight = 156 ClientWidth = 232 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'Tahoma' Font.Style = [] OldCreateOrder = False Position = poDesktopCenter OnCreate = FormCreate OnPaint = FormPaint PixelsPerInch = 96 TextHeight = 13 object CheckBox1: TCheckBox Left = 12 Top = 126 Width = 113 Height = 17 Caption = 'CheckBox1' TabOrder = 0 OnClick = CheckBox1Click end object CheckBox2: TCheckBox Left = 123 Top = 126 Width = 106 Height = 17 Caption = 'CheckBox2' TabOrder = 1 OnClick = CheckBox2Click end end