再學 GDI+[31]: TGPPen - 設置端點連接方式 - SetLineJoin

本例效果圖:

　　代碼文件: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.窗體文件: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端點連接方式枚舉:LineJoin = (
　LineJoinMiter,
　LineJoinBevel,
　LineJoinRound,
　LineJoinMiterClipped
);
TLineJoin = LineJoin;