本例效果图:
![](https://www.cnblogs.com/images/cnblogs_com/del/138617/o_86204.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; procedure TForm1.FormCreate(Sender: TObject); begin CheckBox1.Caption := '执行 Widen'; CheckBox2.Caption := '显示路径中所有的点'; end; procedure TForm1.FormPaint(Sender: TObject); var g: TGPGraphics; p: TGPPen; b1,b2: TGPBrush; path: TGPGraphicsPath; pts: array of TGPPoint; i: Integer; begin g := TGPGraphics.Create(Canvas.Handle); p := TGPPen.Create(aclSlateGray, 20); p.SetEndCap(LineCapArrowAnchor); b1 := TGPSolidBrush.Create(aclRed); b2 := TGPHatchBrush.Create(HatchStyleDiagonalCross, aclSilver, aclSlateGray); path := TGPGraphicsPath.Create; path.AddLine(40, 50, ClientWidth-40, 50); if CheckBox1.Checked then begin path.Widen(p); g.FillPath(b2, path); end else g.DrawPath(p, path); if CheckBox2.Checked then begin SetLength(pts, path.GetPointCount); path.GetPathPoints(PGPPoint(pts), Length(pts)); TGPSolidBrush(b1).SetColor(aclRed); for i := 0 to Length(pts) - 1 do g.FillRectangle(b1, pts[i].X-3, pts[i].Y-3, 6, 6); end; path.Free; b1.Free; b2.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 = 136 ClientWidth = 287 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 = 43 Top = 104 Width = 97 Height = 17 Caption = 'CheckBox1' TabOrder = 0 OnClick = CheckBox1Click end object CheckBox2: TCheckBox Left = 138 Top = 104 Width = 125 Height = 17 Caption = 'CheckBox2' TabOrder = 1 OnClick = CheckBox2Click end end