asp.net登录验证码实现方法

2024-07-10 13:31:18

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前端添加的标签和方法：
验证码：

复制代码代码如下:

	<input id="txtVerifyCode" type="text" maxlength="5" style="line-height: 30px;  height: 30px; width: 80px;border:solid 1px #d4d4d4;" class="input"/> <img src=""      $("#imgValidateCode").click(function () {        DoFresh();      });      DoFresh();    })function DoFresh() {      var img = $("#imgValidateCode");      img.attr("src", "VerifyCode.aspx?random=" + Math.random());    } //添加的方法，src是生成图片的aspx的地址 

然后在项目中在新建一个VerifyCode.aspx，下面是aspx的代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="VerifyCode.aspx.cs" Inherits="Form.VerifyCode" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server">   <title></title> </head> <body>   <form id="form1" runat="server">   <div>     </div>   </form> </body> </html>

接着是aspx.cs的代码：

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Drawing; namespace Form{  public partial class VerifyCode : System.Web.UI.Page  {    public static string HZ;    /// <summary>    /// 验证码的最大长度    /// </summary>    public int MaxLength    {      get { return 10; }    }    /// <summary>    /// 验证码的最小长度    /// </summary>    public int MinLength    {      get { return 1; }    }     protected void Page_Load(object sender, EventArgs e)    {      string[] str = CreateValidateNumber(4);      string strcode = string.Empty;      for (int i = 0; i < str.Length; i++)      {      strcode += str[i];      }    CreateCheckCodeImage(str);      HZ = strcode;      Response.Write(HZ);     //验证码存入session      Session["ValidateCode"] = HZ;    }    /// <summary>    /// 生成验证码    /// </summary>    /// <param name="length">指定验证码的长度</param>    /// <returns>验证码</returns>    public string[] CreateValidateNumber(int length)    {      string Vchar = "1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,p" +      ",q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,P,Q" +      ",R,S,T,U,V,W,X,Y,Z";      string[] VcArray = Vchar.Split(new Char[] { ',' });//拆分成数组       string[] num = new string[length];      int temp = -1;//记录上次随机数值，尽量避避免生产几个一样的随机数     Random rand = new Random();      //采用一个简单的算法以保证生成随机数的不同      for (int i = 1; i < length + 1; i++)      {        if (temp != -1)        {          rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));        }        int t = rand.Next(VcArray.Length-1);        if (temp != -1 && temp == t)        {          return CreateValidateNumber(length);         }        temp = t;        num[i - 1] = VcArray[t];        //num.SetValue(VcArray[t]);        //VNum += VcArray[t];      }      return num;    }   private void CreateCheckCodeImage(string[] checkCode)    {      if (checkCode == null || checkCode.Length <= 0)        return;      System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 32.5)), 60);      System.Drawing.Graphics g = Graphics.FromImage(image);     try      {       //生成随机生成器        Random random = new Random();       //清空图片背景色        g.Clear(Color.White);       //定义颜色        Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };        //画图片的背景噪音线        for (int i = 0; i < 25; i++)        {          int cindex = random.Next(7);          int findex = random.Next(5);          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 Pen(c[cindex]), x1, y1, x2, y2);        }        //定义字体        string[] f = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };       for (int k = 0; k <= checkCode.Length - 1; k++)        {          int cindex = random.Next(7);          int findex = random.Next(5);          Font drawFont = new Font(f[findex], 26, (System.Drawing.FontStyle.Bold));          SolidBrush drawBrush = new SolidBrush(c[cindex]);          float x = 5.0F;          float y = 0.0F;          float width = 42.0F;          float height = 48.0F;          int sjx = random.Next(10);          int sjy = random.Next(image.Height - (int)height);          RectangleF drawRect = new RectangleF(x + sjx + (k * 25), y + sjy, width, height);          StringFormat drawFormat = new StringFormat();          drawFormat.Alignment = StringAlignment.Center;        g.DrawString(checkCode[k], drawFont, drawBrush, drawRect, drawFormat);        }        //画图片的前景噪音点        for (int i = 0; i < 500; i++)        {          int x = random.Next(image.Width);          int y = random.Next(image.Height);           image.SetPixel(x, y, Color.FromArgb(random.Next()));        }        int cindex1 = random.Next(7);        //画图片的边框线        g.DrawRectangle(new Pen(c[cindex1]), 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();      }    }  }}

于是！就可以生成验证码了，然后自己再把编写验证版的判断逻辑写好就可以啦！

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