C#生成中文汉字验证码源码

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

public partial class Admin_ValidCode : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.CreateCheckCodeImage(GenerateCheckCode());

}
private string GenerateCheckCode()
{
int number;
//char code;
string checkCode = String.Empty;

System.Random random = new Random();