• 图片验证码


      1     /// <summary>
      2     /// ValidaterCodeHandler 的摘要说明(此项是建立一般处理数据)
      3     /// </summary>
      4     public class ValidaterCodeHandler : IHttpHandler,IRequiresSessionState
      5     {
      6         public void ProcessRequest(HttpContext context)
      7         {
      8             string chechCode = GenCode1(5);
      9             // 创建用来绘制验证码的位图
     10             System.Drawing.Bitmap image = new System.Drawing.Bitmap(100,23);
     11             //从位图中获取对应的绘图类对象
     12             Graphics g = Graphics.FromImage(image);
     13             // 将产生的验证码先存到Session中,方便与用户填写的验证码进行比较
     14             context.Session["code"] = chechCode;
     15             try
     16             {
     17                 // 生成随机生成器
     18                 Random random = new Random();
     19                 // 清空图片背景色
     20                 g.Clear(Color.White);
     21                 // 画图片的背景噪音线
     22                 for (int i = 0; i < 25; i++)
     23                 {
     24                     int x1 = random.Next(image.Width);
     25                     int x2 = random.Next(image.Width);
     26                     int y2 = random.Next(image.Height);
     27                     int y1 = random.Next(image.Height);
     28                     g.DrawLine(new Pen(Color.Silver),x1,y1,x2,y2);
     29                 }
     30 
     31                 Font font = new Font("Arial",12,System.Drawing.FontStyle.Bold);
     32                 LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0,0,image.Width,image.Height),Color.Blue,Color.DarkRed,1.2F,true);
     33                 g.DrawString(chechCode,font,brush,2,2);
     34                 // 画图片的前景噪音点
     35                 g.DrawRectangle(new Pen(Color.Silver),0,0,image.Width - 1,image.Height - 1);
     36                 MemoryStream ms = new MemoryStream();
     37                 image.Save(ms,ImageFormat.Gif);
     38                 context.Response.ClearContent();
     39                 context.Response.ContentType = "image/Gif";
     40                 context.Response.BinaryWrite(ms.ToArray());
     41             }
     42             finally
     43             {
     44                 g.Dispose();
     45                 image.Dispose();
     46             }
     47         }
     48 
     49         public bool IsReusable
     50         {
     51             get
     52             {
     53                 return false;
     54             }
     55         }
     56 
     57         /// <summary>
     58         /// 产生随机数、字母字符串
     59         /// </summary>
     60         /// <param name="num">随机出几个字符</param>
     61         /// <returns>随机出的字符</returns>
     62         private string GenCode1(int num)
     63         {
     64             string str = "0123456789qwertyuioplkjhgfdsazxcvbnm";
     65             string code = "";
     66             Random rd = new Random();
     67             for (int i = 0; i < num; i++)
     68             {
     69                 code += str.Substring(rd.Next(0,str.Length),1);
     70             }
     71             return code;
     72         }
     73 
     74         /// <summary>
     75         /// 产生汉字
     76         /// </summary>
     77         /// <param name="num">随机出几个字符</param>
     78         /// <returns>随机出的字符串</returns>
     79         private string GenCode2(int num)
     80         {
     81             string str = "啥打法是否客户看大能打开富室发高精度将对方开始";
     82             string code = "";
     83             Random rd = new Random();
     84             for (int i = 0; i < num; i++)
     85             {
     86                 code += str.Substring(rd.Next(0,str.Length),1);
     87             }
     88 
     89             return code;
     90         }
     91     }
     92 
     93 
     94 
     95 
     96    // 页面代码
     97     <head runat="server">
     98     <title></title>
     99     <script type = "text/javascript">
    100         function fresh() {
    101             document.getElementById("code").src = "ValidaterCodeHandler.ashx?time = " + new Date(); 
    102         }
    103     </script>
    104 </head>
    105 <body>
    106     <form id="form1" runat="server">
    107     <div>
    108         登录页面
    109         <br />
    110         <br />
    111         用户名:<asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
    112         <br />
    113         <br />
    114         密&nbsp; 码:<asp:TextBox ID="txtPwd" runat="server" TextMode="Password"></asp:TextBox>
    115         <br />
    116         <br />
    117         验证码:<asp:TextBox ID="txtValidaterCode" runat="server"></asp:TextBox>
    118         <img id = "code" src = "ValidaterCodeHandler.ashx" onclick = "fresh()" />
    119         <a href = "javascript:fresh()">看不清?换一个</a>
    120         <br />
    121         <br />
    122         <asp:Button ID="btnLogin" runat="server" Text="登录" onclick="btnLogin_Click" />
    123 
    124     </div>
    125     </form>
    126 </body>



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  • 原文地址:https://www.cnblogs.com/xjx8205/p/4681654.html
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