c# 和 delphi 的 base64 编码一致问题 webservice

1 delphi部分：

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,EncdDecd;

type
TForm1 = class(TForm)
Edit1: TEdit;
Edit2: TEdit;
Button1: TButton;
Button2: TButton;
Edit3: TEdit;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var s:AnsiString;
begin
s:=edit1.text;
edit2.Text:= EncodeString((s));

// 超越软件 http://www.cyhlw.com
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
edit3.Text:=DecodeString(edit2.text)
end;

end.

2c# 部分：

using System;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Text;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

//Response.ContentEncoding = System.Text.Encoding.GetEncoding( "GB2312" );

}
protected void Button1_Click(object sender, EventArgs e)
{

string str="";

localhost.IIHelloservice oserver = new localhost.IIHelloservice();
str=oserver.sayHello("超越软件 http://www.cyhlw.com");
//localhost.WebService1 oService = new localhost.WebService1();
//Label1.Text = oService.About();
this.TextBox1.Text = str;

byte[] bytes = System.Convert.FromBase64String(str);
str = "";
str = Encoding.Default.GetString(bytes);
TextBox2.Text = str;
//TextBox1.Text=Encoder.get
//byte[] bytes
//this.TextBox1.Text = System.Convert.FromBase64String(str);

}
}