C#实现简单验证码

一、先看一下实现的效果：

二、具体实现

1、封装的helper类，拿来用就行

public class VerificationCodeHelper
    {
        private static Color BackColor = Color.White;
        private static int Width = 62;
        private static int Height = 21;
        private Random _random;
        // private string _code;



        private int _brushNameIndex;

        public byte[] GetVCode(string codeStr)
        {
            _random = new Random();
            using (Bitmap img = new Bitmap(Width, Height))
            {
                // _code = GetRandomCode();
                // System.Web.HttpContext.Current.Session["vcode"] = _code;
                using (Graphics g = Graphics.FromImage(img))
                {
                    g.Clear(Color.White);//绘画背景颜色

                    Paint_Text(g, codeStr);// 绘画文字
                    // g.DrawString(strCode, new Font("微软雅黑", 15), Brushes.Blue, new PointF(5, 2));// 绘画文字
                    Paint_TextStain(img);// 绘画噪音点
                    g.DrawRectangle(Pens.DarkGray, 0, 0, Width - 1, Height - 1);//绘画边框
                    using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
                    {
                        //将图片 保存到内存流中
                        img.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                        //将内存流 里的 数据  转成 byte 数组 返回
                        return ms.ToArray();
                    }
                }
            }

        }

        /// <summary>
        /// 绘画文字
        /// </summary>
        /// <param name="g"></param>
        private void Paint_Text(Graphics g, string code)
        {
            g.DrawString(code, GetFont(), GetBrush(), 3, 1);
        }

        /// <summary>
        /// 绘画文字噪音点
        /// </summary>
        /// <param name="g"></param>
        private void Paint_TextStain(Bitmap b)
        {
            string[] BrushName = new string[] {    "OliveDrab",
                                                  "ForestGreen",
                                                  "DarkCyan",
                                                  "LightSlateGray",
                                                  "RoyalBlue",
                                                  "SlateBlue",
                                                  "DarkViolet",
                                                  "MediumVioletRed",
                                                  "IndianRed",
                                                  "Firebrick",
                                                  "Chocolate",
                                                  "Peru",
                                                  " enrod"
                                             };

            for (int n = 0; n < 30; n++)
            {
                int x = _random.Next(Width);
                int y = _random.Next(Height);
                b.SetPixel(x, y, Color.FromName(BrushName[_brushNameIndex]));

            }

        }
        /// <summary>
        /// 随机取一个字体
        /// </summary>
        /// <returns></returns>
        private Font GetFont()
        {
            string[] FontItems = new string[]{   "Arial", 
                                                  "Helvetica", 
                                                  "Geneva", 
                                                  "sans-serif", 
                                                  "Verdana"
                                              };

            int fontIndex = _random.Next(0, FontItems.Length);
            FontStyle fontStyle = GetFontStyle(_random.Next(0, 2));
            return new Font(FontItems[fontIndex], 12, fontStyle);
        }
        /**/
        /**/
        /**/
        /// <summary>
        /// 随机取一个笔刷
        /// </summary>
        /// <returns></returns>
        private Brush GetBrush()
        {
            Brush[] BrushItems = new Brush[]{     Brushes.OliveDrab,
                                                  Brushes.ForestGreen,
                                                  Brushes.DarkCyan,
                                                  Brushes.LightSlateGray,
                                                  Brushes.RoyalBlue,
                                                  Brushes.SlateBlue,
                                                  Brushes.DarkViolet,
                                                  Brushes.MediumVioletRed,
                                                  Brushes.IndianRed,
                                                  Brushes.Firebrick,
                                                  Brushes.Chocolate,
                                                  Brushes.Peru,
                                                  Brushes.Goldenrod
                                            };

            int brushIndex = _random.Next(0, BrushItems.Length);
            _brushNameIndex = brushIndex;
            return BrushItems[brushIndex];
        }
        /// <summary>
        /// 绘画背景颜色
        /// </summary>
        /// <param name="g"></param>
        private void Paint_Background(Graphics g)
        {
            g.Clear(BackColor);
        }
        /**/
        /**/
        /**/
        /// <summary>
        /// 取一个字体的样式
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        private FontStyle GetFontStyle(int index)
        {
            switch (index)
            {
                case 0:
                    return FontStyle.Bold;
                case 1:
                    return FontStyle.Italic;
                default:
                    return FontStyle.Regular;
            }
        }

        /// <summary>
        /// 取得一个 4 位的随机码
        /// </summary>
        /// <returns></returns>
        public string GetRandomCode()
        {
            return Guid.NewGuid().ToString().Substring(0, 5);
        }
    }

2、HTML页面部分：

 <div class="row cl">
                    <div class="formControls col-xs-8 col-xs-offset-3">
                        <input class="input-text size-L" type="text" placeholder="验证码" onblur="if(this.value==''){this.value='验证码:'}" onclick="if(this.value=='验证码:'){this.value='';}" value="验证码:" style="width:150px;">
                        <img id="checkloing" src="/Login/VCode" width="70" height="40" class="loginFormCheckCodeImg" onclick="reloadcode('/Login/VCode')" title="看不清，换一张" />
                    </div>
                </div>

//刷新验证码 js脚本代码
        function reloadcode(srcStr) {
            document.getElementById("checkloing").src = srcStr + "?rand=" + Math.random();
        }
        var checkInfo = "";
        //检查数据
        function Check() {
            checkInfo = "";
            //检查不能为空的数据
            $("input[Require='True']").each(function (i) {
                var tmpName = $(this).attr("name");
                var strVal = $(this).val();
                strVal = strVal.replace(/\s/g, "")
                if (!strVal)
                    checkInfo += $(this).attr("placeholder") + "不能为空。<br/>";
            });
            if (checkInfo) return false;
            return true;
        }
        $(function () {
            $("#btnLogin").click(function () {
                var ii = layer.load();
                if (!Check()) {
                    layer.close(ii);
                    layer.msg('' + checkInfo, function () { });
                    return;
                }
                $("#loadingDiv").show();
                $.ajax({
                    url: "/Home/Index",
                    type: "post",
                    data: "userName=" + $("#tbUserName").val() + "&pwd=" + $("#tbPWD").val() + "&code=" + $("#checkInput").val(),
                    success: function (data) {
                        debugger;
                        if (data.Result == "0") {
                            layer.close(ii);
                            layer.msg('' + data.MSG);
                            return;
                        } else if (data.Result == "1") {
                            layer.close(ii);
                            window.location.href = "/Home/Index";
                        }
                    },
                    error: function (data) {
                        layer.close(ii);
                        layer.msg('' + data.MSG);
                    }
                });
            });
        });

MVC控制器提供验证码的方法：

[AllowAnonymous]//跳过登陆验证
        public ActionResult VCode()
        {
            VerificationCodeHelper vcode = new VerificationCodeHelper();
            string codeStr = vcode.GetRandomCode();
            if (!string.IsNullOrEmpty(codeStr))
            {
                byte[] arrImg = vcode.GetVCode(codeStr);
                Session["code"] = codeStr;
                return File(arrImg, "image/gif");
            }
            else
            {
                return RedirectToAction("/Login/VCode?rand=" + Guid.NewGuid().ToString().Substring(1, 10), "image/jpeg");
            }
        }

验证页面数据的方法：

[HttpPost]
        public ActionResult Index(string userName, string pwd)
        {
            try
            {
                string vccode = Request.Form["code"];
                if (string.IsNullOrEmpty(vccode))
                    return Json(new { Result = "0", MSG = "请填写验证码" });
                else
                {
                    if (Session["code"] == null)
                        return Json(new { Result = "0", MSG = "验证码已过期，请点击刷新验证码" });
                    string str = Session["code"].ToString();
                    str = str.ToLower();
                    vccode = vccode.ToLower();
                    if (str != vccode)
                        return Json(new { Result = "0", MSG = "验证码填写错误！" });
                    else
                    {
                        Session["code"] = null;
                    }
                    if (string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(pwd))
                    {
                        return Json(new { Result = "0", MSG = "用户或密码没有填写" });
                    }
                    //查询此用户
                    #region 查询此用户
                    List<Models.MySqlUser> adminml = new List<Models.MySqlUser>();
                    Models.MySqlUser admin = new Models.MySqlUser();
                    adminml = IBCodeBll.GetModelList(userName.Trim());

                    if (adminml.Count > 0)
                    {
                        if (!adminml[0].password.ToLower().Equals(Maticsoft.Common.DEncrypt.DESEncrypt.Encrypt2(pwd.Trim()).ToLower()))
                        {
                            return Json(new { Result = "0", MSG = "密码错误！" });
                        }
                    }
                    else
                    {
                        return Json(new { Result = "0", MSG = "用户不在在！" });
                    }
                    #endregion
                    Session["UserName"] = userName.Trim().ToString();
                    return Json(new { Result = "1", MSG = "登录成功！" });
                }
            }
            catch (Exception ex)
            {

                return Json(new { Result = "0", MSG = ex.Message });
            }
        }

参考资料：https://www.cnblogs.com/zhangxiaoyong/p/6210953.html