Delphi 2009之TStringBuilder类[5]: Chars[]属性与CopyTo方法

Delphi 2009之TStringBuilder类[5]: Chars[]属性与CopyTo方法2012-02-15 cnblogs 万一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.