C#验证码的创建与使用示例

2019-10-29 21:15:08

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本文实例讲述了C#验证码的创建与使用方法。分享给大家供大家参考，具体如下：

1、C#创建验证码

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>

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

① 验证码的前段显示代码

复制代码代码如下:

	<img src="/ValidateCode.aspx?ValidateCodeType=1&0.011150883024061309" onclick="this.src='/ValidateCode.aspx?ValidateCodeType=1&'+Math.random();" id="imgValidateCode"  <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"    <asp:Button runat="server" id="btnVal" Text="提交" onclick="btnVal_Click" />  </div>  </form></body></html>

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;    }  }}

希望本文所述对大家C#程序设计有所帮助。

注：相关教程知识阅读请移步到c#教程频道。

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