再學GDI+[27]: TGPPen - 畫筆樣式 - SetDashStyle

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)
　　ComboBox1: TComboBox;
　　procedure FormCreate(Sender: TObject);
　　procedure FormPaint(Sender: TObject);
　　procedure ComboBox1Change(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI, TypInfo;
procedure TForm1.FormCreate(Sender: TObject);
var
　i: Integer;
begin
　for i := 0 to 5 do
　　ComboBox1.Items.Add(GetEnumName(TypeInfo(TDashStyle), i));
　ComboBox1.ItemIndex := 0;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　p: TGPPen;
begin
　g := TGPGraphics.Create(Canvas.Handle);
　g.Clear($FFFFFFFF);
　p := TGPPen.Create(aclLimeGreen, 10);
　p.SetDashStyle(TDashStyle(ComboBox1.ItemIndex));
　g.DrawLine(p, 0, 0, ClientWidth, ClientHeight);
　p.Free;
　g.Free;
end;
procedure TForm1.ComboBox1Change(Sender: TObject);
begin
　Repaint;
end;
end.

窗體文件:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClientHeight = 167
　ClientWidth = 242
　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 ComboBox1: TComboBox
　　Left = 89
　　Top = 8
　　Width = 145
　　Height = 21
　　ItemHeight = 13
　　TabOrder = 0
　　Text = 'ComboBox1'
　　OnChange = ComboBox1Change
　end
end

畫筆樣式枚舉的定義:DashStyle = (
　DashStyleSolid,　　　{指定實線}
　DashStyleDash,　　　 {指定由劃線段組成的直線}
　DashStyleDot,　　　　{指定由點構成的直線}
　DashStyleDashDot,　　{指定由重復的劃線點圖案構成的直線}
　DashStyleDashDotDot, {指定由重復的劃線點點圖案構成的直線}
　DashStyleCustom　　　{指定用戶定義的自定義劃線段樣式}
);
TDashStyle = DashStyle;