生成验证码代码!

代码如下:

protected void Page_Load(object sender, System.EventArgs e)   {                Response.Expires = -1;        Response.AddHeader("Pragma", "no-cache");        Response.AddHeader("cache-ctrol", "no-cache");        GetCode();    }    private void GetCode()    {        string VNum = "";        VNum = MakeValidateCode();         CookieManage.SetCookie("CheckCode", VNum);        CreateImage(VNum);    }    //生成随机的验证码    string MakeValidateCode()    {          char[] s = new char[]{'2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','j','k','l','m','n','p','q','r','s','t','u','v','w','x','y','z'};          string num = "";         Random r = new Random();        for (int i = 0; i < 4; i++)        {            num += s[r.Next(0, s.Length)].ToString().ToUpper();        }        return num;    }    //生成代码图片    private void CreateImage(string VNum)    {        Random rr = new Random();        validateimage = new Bitmap(100, 30, PixelFormat.Format32bppArgb);        Rectangle rect = new Rectangle(0, 0, 100, 30);        g = Graphics.FromImage(validateimage);        g.FillRectangle(new SolidBrush(Color.FromArgb(255, 255, 255)), rect);        g.FillRectangle(new SolidBrush(Color.FromArgb(255, 255, 255)), rect);        g.DrawString(VNum, new Font("Verdana", 18, FontStyle.Italic), new LinearGradientBrush(rect, Color.FromArgb(rr.Next(100, 255), rr.Next(100, 255), rr.Next(100, 255)), Color.FromArgb(rr.Next(40, 200), rr.Next(40, 200), rr.Next(40, 200)), LinearGradientMode.BackwardDiagonal), new PointF(10, 0));        g.DrawLine(new Pen(new LinearGradientBrush(rect, Color.FromArgb(rr.Next(150, 255), rr.Next(100, 255), rr.Next(200, 255)), Color.FromArgb(rr.Next(255), rr.Next(255), rr.Next(255)), LinearGradientMode.Horizontal), 1), 0, rect.Height / 2, rect.Width, rr.Next(rect.Height / 2, rect.Height));        g.DrawLine(new Pen(new LinearGradientBrush(rect, Color.FromArgb(rr.Next(255), rr.Next(255), rr.Next(255)), Color.FromArgb(rr.Next(255), rr.Next(255), rr.Next(255)), LinearGradientMode.Horizontal), 1), 0, rect.Height / 3, rect.Width, rr.Next(0, rect.Height / 2));        g.Save();        MemoryStream ms = new MemoryStream();        validateimage.Save(ms, System.Drawing.Imaging.ImageFormat.Png);        Response.ClearContent();        Response.ContentType = "image/bitmap";        Response.BinaryWrite(ms.ToArray());        Response.End();    }

//在其他Html页的中实现    function refreshImg()    {        var imgCode = document.getElementById("<%=imgCode.ClientID %>");        var siteDoain="<%=ClassBase.siteDomain %>"        imgCode.src = siteDoain+"/Admin/Manage/Common/Code.aspx?do="+Math.random();    } <--!<div style="padding-top:3px;">    验证码：<asp:TextBox ID="checkCode" runat="server" Width="81px" style="border:solid 1px #E5E5E5;"></asp:TextBox>&nbsp;    <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="checkCode"        ErrorMessage="*"></asp:RequiredFieldValidator><img src="~/验证码单独页面所在文件夹/Code.aspx(验证吗页面)" id="imgCode" alt="点击刷新验证码" style="border: 1px solid #E0E0E0;height: 25px; padding: 2px; cursor: pointer;" align="absmiddle" onclick="javascript:refreshImg();" runat="server" /> </div>!-->