各位朋友们，请问怎么实现验证码验证呀？
有什么办法能实现验证码验证呢？  
  验证码是一个image控件加载一个checkcode.aspx文件。
  请问怎么实现验证呢？ 都有什么方法呢? 最近折磨我几天了。

------解决方案--------------------
using System;
using System.Collections.Generic;
//using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;

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


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

System.Random random = new Random();

for (int i = 0; i < 5; i++)
{
number = random.Next();

//if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
//else
// code = (char)('A' + (char)(number % 26));

checkCode += code.ToString();
}

//cookie判断
//Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
Session["vcode"] = checkCode;
return checkCode;
}


private void CreateCheckCodeImage(string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;

System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
Graphics g = Graphics.FromImage(image);

try
{
//生成随机生成器
Random random = new Random();

//清空图片背景色
g.Clear(Color.White);

//画图片的背景噪音线
for (int i = 0; i < 10; i++)
{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);

g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
}

Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(checkCode, font, brush, 2, 2);

//画图片的前景噪音点
for (int i = 0; i < 100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);

image.SetPixel(x, y, Color.FromArgb(random.Next()));
}

//画图片的边框线
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}


引用
<img src="ValidateCode.aspx" onclick="this.src=this.src+'?Math.random()';"/>
 
这是页面代码 我正在用的。
------解决方案--------------------
你把那个aspx文件就当成一个图片 路径赋值给 image 的scr属性 让它显示出验证码就行了啊 就这么简单，，，这个aspx文件有个session值啊 后台吧用户输入的跟这个session一比较 不就实