zoukankan      html  css  js  c++  java
  • Ajax校验验证码(可以设置为数字、字母、中文汉字等,背景图有干扰线)

    一般处理程序,获得验证码

        /// <summary>
        /// VCode 的摘要说明
        /// </summary>
        public class VCode : IHttpHandler,System.Web.SessionState.IRequiresSessionState
        {
            public void ProcessRequest(HttpContext context)
            {
                //System.Threading.Thread.Sleep(5000);
                context.Response.ContentType = "image/jpeg";
                string code = GetRndNumStr();
                //string code = GetRndNum();
                //string code = GetRndStr();
                //string code = GetRndCh();
                context.Session["VCode"] = code;
                using (Bitmap img = CreateImages(code, "ch"))
                {
                    img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                }
            }
            // 数字+字母随机
            private string GetRndNumStr()
            {
                string Vchar = "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,0,1,2,3,4,5,6,7,8,9";
                string[] VcArray = Vchar.Split(',');
                string checkCode = string.Empty;
                Random rand = new Random();
                for (int i = 0; i < 4; i++)
                {
                    int t = rand.Next(VcArray.Length);
                    checkCode += VcArray[t];
                }
                return checkCode;
            }
            // 数字随机数
            private string GetRndNum()
            {
                string code = string.Empty;
                Random random = new Random();
                for (int i = 0; i < 4; i++)
                {
                    code += random.Next(9);
                }
                return code;
            }
            // 英文随机
            private string GetRndStr()
            {
                string Vchar = "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
                string[] VcArray = Vchar.Split(',');
                string checkCode = string.Empty;
                Random rand = new Random();
                for (int i = 0; i < 4; i++)
                {
                    int t = rand.Next(VcArray.Length);
                    checkCode += VcArray[t];
                }
                return checkCode;
            }
            // 中文随机
            private string GetRndCh()
            {
                System.Text.Encoding gb = System.Text.Encoding.Default;//获取GB2312编码页(表)
                object[] bytes = CreateRegionCode(4);//生4个随机中文汉字编码
                string[] str = new string[4];
                System.Text.StringBuilder sb = new System.Text.StringBuilder();
                for (int i = 0; i < 4; i++)
                {
                    //根据汉字编码的字节数组解码出中文汉字
                    str[i] = gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[])));
                    sb.Append(str[i].ToString());
                }
                return sb.ToString();
            }
            // 产生随机中文字符
            private static object[] CreateRegionCode(int strlength)
            {
                //定义一个字符串数组储存汉字编码的组成元素
                string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
                Random rnd = new Random();
                object[] bytes = new object[strlength];
    
                for (int i = 0; i < strlength; i++)
                {
                    //区位码第1位
                    int r1 = rnd.Next(11, 14);
                    string str_r1 = rBase[r1].Trim();
                    //区位码第2位
                    rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i);
                    int r2;
                    if (r1 == 13)
                    {
                        r2 = rnd.Next(0, 7);
                    }
                    else
                    {
                        r2 = rnd.Next(0, 16);
                    }
                    string str_r2 = rBase[r2].Trim();
    
                    //区位码第3位
                    rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机种子
                    int r3 = rnd.Next(10, 16);
                    string str_r3 = rBase[r3].Trim();
    
                    //区位码第4位
                    rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i);
                    int r4;
                    if (r3 == 10)
                    {
                        r4 = rnd.Next(1, 16);
                    }
                    else if (r3 == 15)
                    {
                        r4 = rnd.Next(0, 15);
                    }
                    else
                    {
                        r4 = rnd.Next(0, 16);
                    }
                    string str_r4 = rBase[r4].Trim();
                    //定义两个字节变量存储产生的随机汉字区位码
                    byte byte1 = Convert.ToByte(str_r1 + str_r2, 16);
                    byte byte2 = Convert.ToByte(str_r3 + str_r4, 16);
    
                    //将两个字节变量存储在字节数组中
                    byte[] str_r = new byte[] { byte1, byte2 };
    
                    //将产生的一个汉字的字节数组放入object数组中
                    bytes.SetValue(str_r, i);
                }
                return bytes;
            }
            // 画图片的背景图+干扰线 
            private Bitmap CreateImages(string checkCode, string type)
            {
                int step = 0;
                if (type == "ch")
                {
                    step = 5;//中文字符,边界值做大
                }
                int iwidth = (int)(checkCode.Length * (13 + step));
                System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 22);
                Graphics g = Graphics.FromImage(image);
                g.Clear(Color.White);//清除背景色
                Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };//定义随机颜色
                string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
                Random rand = new Random();
    
                for (int i = 0; i < 50; i++)
                {
                    int x1 = rand.Next(image.Width);
                    int x2 = rand.Next(image.Width);
                    int y1 = rand.Next(image.Height);
                    int y2 = rand.Next(image.Height);
                    g.DrawLine(new Pen(Color.LightGray, 1), x1, y1, x2, y2);//根据坐标画线
                }
    
                for (int i = 0; i < checkCode.Length; i++)
                {
                    int cindex = rand.Next(7);
                    int findex = rand.Next(5);
    
                    Font f = new System.Drawing.Font(font[findex], 10, System.Drawing.FontStyle.Bold);
                    Brush b = new System.Drawing.SolidBrush(c[cindex]);
                    int ii = 4;
                    if ((i + 1) % 2 == 0)
                    {
                        ii = 2;
                    }
                    g.DrawString(checkCode.Substring(i, 1), f, b, 3 + (i * (12 + step)), ii);
    
                }
                g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                return image;
            }
    
            public bool IsReusable
            {
                get
                {
                    return false;
                }
            }
        }
    HTML代码
        验证码:
        <input id="txtVcode" type="text" />
        <img alt="" id="imgCode" src="/js/vcode/VCode.ashx" />
        <a id="aCode" href="javascript:void(0)">看不清,换一张</a>
        <div id="txtVcodeTip"></div>
    Javascript变换验证码代码
    function getVCode() {
        $("#imgCode").attr("src", "/js/vcode/VCode.ashx?r=" + new Date());
    }
    $(function () {
        //验证码
        var imgCode = $("#imgCode");
        imgCode.attr("alt", "点击获取验证码");
        imgCode.attr("title", "点击更换验证码");
        imgCode.css("cursor", "pointer");
        imgCode.click(function () {//点击验证码本身切换验证码
            getVCode();
        });
        //点击文字超链接更换验证码
        var aCode = $("#aCode");
        aCode.click(function () {
            getVCode();
        });
        //验证码提示消息
        var vcodeMsg = $("#txtVcodeTip");
        vcodeMsg.css("color", "Red");
        var vcode = $("#txtVcode");
        vcode.blur(function () {
            if ($.trim(vcode.val()) == '') {
                vcodeMsg.text("验证码不能为空");
                return false;
            } else {
                $.post("/js/vcode/CheckVCode.ashx", { "vcode": $.trim(vcode.val()) }, function (data) {
                    vcodeMsg.text(data);
                });
            }
        }).focus(function () {
            vcodeMsg.text("");
        });
    });

    CheckVCode.ashx代码

        public class CheckVCode : IHttpHandler, System.Web.SessionState.IRequiresSessionState
        {
    
            public void ProcessRequest(HttpContext context)
            {
                context.Response.ContentType = "text/plain";
                string vcode = context.Request["vcode"];
                context.Response.Write(CheckCode(vcode));
            }
    
            public static string CheckCode(string vcode)
            {
                if (HttpContext.Current.Session["VCode"] != null)
                {
                    string sysCode = HttpContext.Current.Session["VCode"].ToString();
                    //使用  Compare  方法,这个方法可以做大小写忽略的比较,并且不会创建新字符串
                    if (String.Compare(vcode, sysCode, true) == 0)
                    {
                        return "ok";
                    }
                    else
                    {
                        return "验证码输入错误,重新输入";
                    }
                }
                else
                {
                    return "验证码过期,请更换验证码";
                }
            }
    
            public bool IsReusable
            {
                get
                {
                    return false;
                }
            }
        }


    版权声明:本文为博主原创文章,未经博主允许不得转载。

  • 相关阅读:
    spring 之 AOP
    spring 之 动态代理
    为 NSDate 添加扩展类 判断时间
    iOS 日期相关总结
    iOS 请求出现 "Request failed: bad request (400)"
    NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9802) 解决办法
    poj-3302
    辽宁省赛——杨鲁斯卡尔专场-J
    辽宁省赛——杨鲁斯卡尔专场 -F
    zzuli训练赛_05_13-D
  • 原文地址:https://www.cnblogs.com/ful1021/p/4804477.html
Copyright © 2011-2022 走看看