本例效果图:
![](https://www.cnblogs.com/images/cnblogs_com/del/138617/o_86134.gif)
代码文件:
![](https://www.cnblogs.com/images/cnblogs_com/del/138617/o_86134.gif)
代码文件:
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) ListBox1: TListBox; procedure FormCreate(Sender: TObject); procedure FormPaint(Sender: TObject); procedure ListBox1Click(Sender: TObject); end; var Form1: TForm1; implementation {$R *.dfm} uses GDIPOBJ, GDIPAPI, TypInfo; procedure TForm1.FormCreate(Sender: TObject); var i: Integer; begin for i := 0 to 3 do ListBox1.Items.Add(GetEnumName(TypeInfo(TLineJoin),i)); ListBox1.ItemIndex := 0; end; procedure TForm1.FormPaint(Sender: TObject); const PtArr: array[0..2] of TGPPoint = ((X:50;Y:150), (X:240;Y:30), (X:240;Y:150)); var g: TGPGraphics; p: TGPPen; begin g := TGPGraphics.Create(Canvas.Handle); p := TGPPen.Create(aclBlueViolet, 28); p.SetLineJoin(TLineJoin(ListBox1.ItemIndex)); g.DrawPolygon(p, PGPPoint(@PtArr), Length(PtArr)); p.Free; g.Free; end; procedure TForm1.ListBox1Click(Sender: TObject); begin Repaint; end; end.窗体文件:
object Form1: TForm1 Left = 0 Top = 0 Caption = 'Form1' ClientHeight = 177 ClientWidth = 382 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 ListBox1: TListBox Left = 277 Top = 0 Width = 105 Height = 177 Align = alRight ItemHeight = 13 TabOrder = 0 OnClick = ListBox1Click ExplicitHeight = 173 end end端点连接方式枚举:
LineJoin = ( LineJoinMiter, LineJoinBevel, LineJoinRound, LineJoinMiterClipped ); TLineJoin = LineJoin;