ASP.NET 實現驗證碼以及重新整理驗證碼的小例子

實現代碼

/// <summary>    /// 產生驗證碼圖片，儲存session名稱VerificationCode    /// </summary>    public static void CreateVerificationCode()    {        int number;        string checkCode = string.Empty;        //隨機數種子        Random randoms = new Random();        for (int i = 0; i < 4; i++) //校正碼長度為4        {            //隨機的整數            number = randoms.Next();            //字元從0-9,A-Z中隨機產生,對應的ASCII碼分別為            //48-57,65-90            number = number % 36;            if (number < 10)            {                number += 48;            }            else            {                number += 55;            }            checkCode += ((char)number).ToString();        }        //在session中儲存校正碼        System.Web.HttpContext.Current.Session["VerificationCode"] = checkCode;        //若校正碼為空白，則直接返回        if (checkCode == null || checkCode.Trim() == String.Empty)        {            return;        }        //根據校正碼的長度確定輸出圖片的長度        System.Drawing.Bitmap image = new System.Drawing.Bitmap(55, 20);//(int)Math.Ceiling(Convert.ToDouble(checkCode.Length * 15))        //建立Graphics對象        Graphics g = Graphics.FromImage(image);        try        {            //產生隨機數種子            Random random = new Random();            //清空圖片背景色            g.Clear(Color.White);            //畫圖片的背景雜音線 10條            //---------------------------------------------------            for (int i = 0; i < 10; i++)            {                //噪音線起點座標(x1,y1),終點座標(x2,y2)                int x1 = random.Next(image.Width);                int x2 = random.Next(image.Width);                int y1 = random.Next(image.Height);                int y2 = random.Next(image.Height);                //用銀色畫出噪音線                g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);            }            //---------------------------------------------------            //Brush b = Brushes.Silver;            //g.FillRectangle(b, 0, 0, image.Width, image.Height);            //---------------------以上兩種任選其一------------------------------            //輸出圖片中校正碼的字型: 12號Arial,粗斜體            Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));            //線性漸層畫刷            LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.Purple, 1.2f, true);            g.DrawString(checkCode, font, brush, 2, 2);            //畫圖片的前景噪音點 50個            for (int i = 0; i < 50; i++)            {                int x = random.Next(image.Width);                int y = random.Next(image.Height);                image.SetPixel(x, y, Color.FromArgb(random.Next()));            }            //畫圖片的邊框線            g.DrawRectangle(new Pen(Color.Peru), 0, 0, image.Width - 1, image.Height - 1);            //建立記憶體流用於輸出圖片            using (MemoryStream ms = new MemoryStream())            {                //圖片格式指定為png                image.Save(ms, ImageFormat.Jpeg);                //清除緩衝區流中的所有輸出                System.Web.HttpContext.Current.Response.ClearContent();                //輸出資料流的HTTP MIME類型設定為"image/Png"                System.Web.HttpContext.Current.Response.ContentType = "image/Jpeg";                //輸出圖片的二進位流                System.Web.HttpContext.Current.Response.BinaryWrite(ms.ToArray());            }        }        finally        {            //釋放Bitmap對象和Graphics對象            g.Dispose();            image.Dispose();        }    }

建立一個aspx頁面

 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="AuthCode.aspx.cs" Inherits="AuthCode" %> <%Help.CreateVerificationCode(); %>

添加HTML代碼,引用

 <div class="positionR">     <label>驗證碼：</label>     <span class="style1"> *</span>     <input type="text" class="yanZm" runat="Server" reg="^.+$" id="txtAuthCode" tip="請輸入驗證碼!" />     <img class="yanZm_img" src="AuthCode.aspx" alt="" id="imgAuthCode" /> </div>

如何?重新整理?

     <script type="text/javascript">         $("#imgAuthCode").click(function () {             $(this).attr("src", "AuthCode.aspx?code=" + (new Date()).getTime());         });     </script>