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://HdhCmsTestw3.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" csharp" id="highlighter_239683">
<html xmlns= "http://HdhCmsTestw3.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>
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。
dy("nrwz");