C#验证码的使用

来源：互联网发布：2016全国地区数据库编辑：程序博客网时间：2024/05/21 15:42

1、C#创建验证码

1.1 创建获取验证码页面（ValidateCode.aspx）

<html xmlns="http://www.w3.org/1999/xhtml"><head runat="server">    <title>获取验证码</title></head><body>    <form id="form1" runat="server">        <div>获取验证码</div>    </form></body></html>

1.2 编写获取验证码代码（ValidateCode.aspx.cs）

/// <summary>/// 验证码类型(0-字母数字混合,1-数字,2-字母)/// </summary>private string validateCodeType = "0";/// <summary>/// 验证码字符个数/// </summary>private int validateCodeCount = 4;/// <summary>/// 验证码的字符集，去掉了一些容易混淆的字符/// </summary>char[] character = { '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };protected void Page_Load(object sender, EventArgs e){    //取消缓存    Response.BufferOutput = true;    Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));    Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);    Response.AppendHeader("Pragma", "No-Cache");    //获取设置参数    if (!string.IsNullOrEmpty(Request.QueryString["validateCodeType"]))    {        validateCodeType = Request.QueryString["validateCodeType"];    }    if (!string.IsNullOrEmpty(Request.QueryString["validateCodeCount"]))    {        int.TryParse(Request.QueryString["validateCodeCount"], out validateCodeCount);    }    //生成验证码    this.CreateCheckCodeImage(GenerateCheckCode());}private string GenerateCheckCode(){    char code ;    string checkCode = String.Empty;    System.Random random = new Random();    for (int i = 0; i < validateCodeCount; i++)    {        code = character[random.Next(character.Length)];        // 要求全为数字或字母        if (validateCodeType == "1")        {            if ((int)code < 48 || (int)code > 57)            {                i--;                continue;            }        }        else if (validateCodeType == "2")        {            if ((int)code < 65 || (int)code > 90)            {                i--;                continue;            }        }        checkCode += code;    }    Response.Cookies.Add(new System.Web.HttpCookie("CheckCode", checkCode));    this.Session["CheckCode"] = 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*15.0+40)), 23);    System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);    try    {        //生成随机生成器        Random random = new Random();        //清空图片背景色        g.Clear(System.Drawing.Color.White);        //画图片的背景噪音线        for (int i = 0; i < 25; 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 System.Drawing.Pen(System.Drawing.Color.Silver), x1, y1, x2, y2);        }        System.Drawing.Font font = new System.Drawing.Font("Arial", 14, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));        System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new System.Drawing.Rectangle(0, 0, image.Width, image.Height), System.Drawing.Color.Blue, System.Drawing.Color.DarkRed, 1.2f, true);        int cySpace = 16;        for (int i = 0; i < validateCodeCount; i++)        {            g.DrawString(checkCode.Substring(i, 1), font, brush, (i + 1) * cySpace, 1);        }        //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, System.Drawing.Color.FromArgb(random.Next()));        }        //画图片的边框线        g.DrawRectangle(new System.Drawing.Pen(System.Drawing.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();    }}

2、验证码的使用

2.1 验证码的前段显示代码

<img src="/ValidateCode.aspx?ValidateCodeType=1&0.011150883024061309" onclick="this.src='/ValidateCode.aspx?ValidateCodeType=1&'+Math.random();" id="imgValidateCode" alt="点击刷新验证码" title="点击刷新验证码" style="cursor: pointer;">

2.2 创建验证码测试页面（ValidateTest.aspx）

<html xmlns="http://www.w3.org/1999/xhtml"><head runat="server">    <title>验证码测试</title></head><body>    <form id="form1" runat="server">    <div>        <input runat="server" id="txtValidate" />        <img src="/ValidateCode.aspx?ValidateCodeType=1&0.011150883024061309" onclick="this.src='/ValidateCode.aspx?ValidateCodeType=1&'+Math.random();" id="imgValidateCode" alt="点击刷新验证码" title="点击刷新验证码" style="cursor: pointer;">        <asp:Button runat="server" id="btnVal" Text="提交" onclick="btnVal_Click"  />    </div>    </form></body></html>

2.3 编写验证码测试的提交代码（ValidateTest.aspx.cs）

protected void btnVal_Click(object sender, EventArgs e){    bool result = false;   //验证结果    string userCode = this.txtValidate.Value; //获取用户输入的验证码    if (String.IsNullOrEmpty(userCode))    {         //请输入验证码        return;    }    string validCode = this.Session["CheckCode"] as String;  //获取系统生成的验证码    if (!string.IsNullOrEmpty(validCode))    {        if (userCode.ToLower() == validCode.ToLower())        {            //验证成功            result = true;        }        else        {            //验证失败            result = false;        }    }}