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）
获取验证码
② 编写获取验证码代码（ValidateCode.aspx.cs）
////// 验证码类型(0-字母数字混合,1-数字,2-字母) /// private string validateCodeType = "0"; ////// 验证码字符个数 /// private int validateCodeCount = 4; ////// 验证码的字符集，去掉了一些容易混淆的字符 /// 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:
② 创建验证码测试页面（ValidateTest.aspx）
验证码测试
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;
}
}
}
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希望本文所述对大家C#程序设计有所帮助。