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.