Delphi 2009之TStringBuilder類[5]: Chars[]屬性與CopyTo方法

unit Unit1;

interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, StdCtrls;
type
　TForm1 = class(TForm)
　　Button1: TButton;
　　Button2: TButton;
　　procedure Button1Click(Sender: TObject);
　　procedure Button2Click(Sender: TObject);
　end;

var

　Form1: TForm1;
implementation
{$R *.dfm}

//TStringBuilder.CopyTo

procedure TForm1.Button1Click(Sender: TObject);
var
　sb: TStringBuilder;
　arr: TCharArray;
　i: Integer;
begin
　sb := TStringBuilder.Create;
　sb.Append('123456789');
　SetLength(arr, 9);
　for i := Low(arr) to High(arr) do arr[i] := '*';
　sb.CopyTo(3, arr, 1, 5);
　ShowMessage(PChar(arr));　 {*45678***}
　sb.Free;
end;

//TStringBuilder.Chars

procedure TForm1.Button2Click(Sender: TObject);
var
　sb: TStringBuilder;
begin
　sb := TStringBuilder.Create('Delphi 2009');
　ShowMessage(sb.Chars[0]);　　　　　　 {D}
　ShowMessage(sb.Chars[sb.Length - 1]); {9}
　sb.Free;
end;
end.