再學GDI+[26]: TGPPen - 畫筆對齊 - SetAlignment

本例效果圖:

代碼文件:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, StdCtrls, ExtCtrls;
type
　TForm1 = class(TForm)
　　RadioGroup1: TRadioGroup;
　　procedure FormPaint(Sender: TObject);
　　procedure FormCreate(Sender: TObject);
　　procedure RadioGroup1Click(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormCreate(Sender: TObject);
begin
　with RadioGroup1 do
　begin
　　Align := alBottom;
　　Items.Add('PenAlignmentCenter');
　　Items.Add('PenAlignmentInset');
　　Columns := 2;
　　ItemIndex := 0;
　end;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　p: TGPPen;
　rect: TRect;
begin
　g := TGPGraphics.Create(Canvas.Handle);
　g.Clear($FFFFFFFF);
　p := TGPPen.Create($FFEE82EE, 20);
　rect := ClientRect;
　InflateRect(rect, -50, -50);
　OffsetRect(rect, 0, -20);
　p.SetAlignment(TPenAlignment(RadioGroup1.ItemIndex));
　g.DrawRectangle(p, MakeRect(rect));
　p.SetColor($FF000000);
　p.SetWidth(1.5);
　g.DrawRectangle(p, MakeRect(rect));
　p.Free;
　g.Free;
end;
procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
　Repaint;
end;
end.

窗體文件:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClientHeight = 198
　ClientWidth = 277
　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 RadioGroup1: TRadioGroup
　　Left = 8
　　Top = 152
　　Width = 185
　　Height = 38
　　Caption = 'RadioGroup1'
　　TabOrder = 0
　　OnClick = RadioGroup1Click
　end
end

畫筆對齊方式:

Delphi 微軟 說明 PenAlignmentCenter Center 指定 Pen 對象以理論的線條為中心。 PenAlignmentInset Inset 指定 Pen 被定位於理論的線條內。 無定義 Left 指定將 Pen 定位於理論的線條的左側。 無定義 Outset 指定將 Pen 定位於理論的線條外。 無定義 Right 指定將 Pen 定位於理論的線條的右側。