• ASP.net 验证码(C#) MVC


    http://blog.163.com/xu_shuhao/blog/static/5257748720101022697309/

    网站添加验证码,主要为防止机器人程序批量注册,或对特定的注册用户用特定程序暴力破解方式,以进行不断的登录、灌水等危害网站的操作。验证码被广泛应用在注册、登录、留言等提交信息到服务器端处理的页面中。
         在ASP.NET网站中应用验证码是很容易的,网上有很多的解决方案。最近在做一个OA项目,因系统采用的ASP.NET MVC框架,同样在登录页中需用到验证码,故需将原来在ASP.NET网站中使用的验证码移植到ASP.NET MVC中。
         原ASP.NET网站用来生成验证码的类文件ValidateCode.cs:

    ASP.net 验证码(C) MVC - Yiraner - 依然、依然
    using System;
    using System.Drawing;
    using System.Drawing.Imaging;
    using System.Web.UI;
    using System.Drawing.Drawing2D;
    using System.IO;
    namespace SeniOA.MVC
    {
    /// <summary>
    /// 生成验证码的类
    /// </summary>
    public class ValidateCode
        {
    public ValidateCode()
            {
            }
    /// <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; }
            }
    /// <summary>
    /// 生成验证码
    /// </summary>
    /// <param name="length">指定验证码的长度</param>
    /// <returns></returns>
    public string CreateValidateCode(int length)
            {
    int[] randMembers = new int[length];
    int[] validateNums = new int[length];
    string validateNumberStr = "";
    //生成起始序列值
    int seekSeek = unchecked((int)DateTime.Now.Ticks);
                Random seekRand = new Random(seekSeek);
    int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
    int[] seeks = new int[length];
    for (int i = 0; i < length; i++)
                {
                    beginSeek += 10000;
                    seeks[i] = beginSeek;
                }
    //生成随机数字
    for (int i = 0; i < length; i++)
                {
                    Random rand = new Random(seeks[i]);
    int pownum = 1 * (int)Math.Pow(10, length);
                    randMembers[i] = rand.Next(pownum, Int32.MaxValue);
                }
    //抽取随机数字
    for (int i = 0; i < length; i++)
                {
    string numStr = randMembers[i].ToString();
    int numLength = numStr.Length;
                    Random rand = new Random();
    int numPosition = rand.Next(0, numLength - 1);
                    validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
                }
    //生成验证码
    for (int i = 0; i < length; i++)
                {
                    validateNumberStr += validateNums[i].ToString();
                }
    return validateNumberStr;
            }
    /// <summary>
    /// 创建验证码的图片
    /// </summary>
    /// <param name="containsPage">要输出到的page对象</param>
    /// <param name="validateNum">验证码</param>
    public void CreateValidateGraphic(string validateCode)
            {
                Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
                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);
    //画图片的干扰线
    for (int i = 0; i < 25; i++)
                    {
    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(Color.Silver), x1, y1, x2, y2);
                    }
                    Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
                    LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
                     Color.Blue, Color.DarkRed, 1.2f, true);
                    g.DrawString(validateCode, font, brush, 3, 2);
    //画图片的前景干扰点
    for (int i = 0; i < 100; i++)
                    {
    int x = random.Next(image.Width);
    int y = random.Next(image.Height);
                        image.SetPixel(x, y, Color.FromArgb(random.Next()));
                    }
    //画图片的边框线
                    g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    //保存图片数据
                    MemoryStream stream = new MemoryStream();
                    image.Save(stream, ImageFormat.Jpeg);
    //输出图片流
                    containsPage.Response.Clear();
                    containsPage.Response.ContentType = "image/jpeg";
                    containsPage.Response.BinaryWrite(stream.ToArray());
                }
    finally
                {
                    g.Dispose();
                    image.Dispose();
                }
            }
    /// <summary>
    /// 得到验证码图片的长度
    /// </summary>
    /// <param name="validateNumLength">验证码的长度</param>
    /// <returns></returns>
    public static int GetImageWidth(int validateNumLength)
            {
    return (int)(validateNumLength * 12.0);
            }
    /// <summary>
    /// 得到验证码的高度
    /// </summary>
    /// <returns></returns>
    public static double GetImageHeight()
            {
    return 22.5;
            }
        }
    }

        为适合ASP.NET MVC框架,修改其输出图片流的方法CreateValidateGraphic为:

    ASP.net 验证码(C) MVC - Yiraner - 依然、依然
    /// <summary>
    /// 创建验证码的图片
    /// </summary>
    /// <param name="containsPage">要输出到的page对象</param>
    /// <param name="validateNum">验证码</param>
    public byte[] CreateValidateGraphic(string validateCode)
    {
        Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
        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);
    //画图片的干扰线
    for (int i = 0; i < 25; i++)
            {
    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(Color.Silver), x1, y1, x2, y2);
            }
            Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
            LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
             Color.Blue, Color.DarkRed, 1.2f, true);
            g.DrawString(validateCode, font, brush, 3, 2);
    //画图片的前景干扰点
    for (int i = 0; i < 100; i++)
            {
    int x = random.Next(image.Width);
    int y = random.Next(image.Height);
                image.SetPixel(x, y, Color.FromArgb(random.Next()));
            }
    //画图片的边框线
            g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    //保存图片数据
            MemoryStream stream = new MemoryStream();
            image.Save(stream, ImageFormat.Jpeg);
    //输出图片流
    return stream.ToArray();
        }
    finally
        {
            g.Dispose();
            image.Dispose();
        }
    }

        在Controller.cs中,添加Action,用来设置将生成的验证码存入Session,并输出验证码图片:

    ASP.net 验证码(C) MVC - Yiraner - 依然、依然
    public ActionResult GetValidateCode()
    {
        ValidateCode vCode = new ValidateCode();
    string code = vCode.CreateValidateCode(5);
        Session["ValidateCode"] = code;
    byte[] bytes = vCode.CreateValidateGraphic(code);
    return File(bytes, @"image/jpeg");
    }

        调用方式为:在需要使用验证码的页面中,加入<img>标签:
    <img id="valiCode" style="cursor: pointer;" src="../Account/GetValidateCode" alt="验证码" />
        效果如下图:

        到于Account/Login这个Action中的处理,只需加入对Session中验证码的判断:

    ASP.net 验证码(C) MVC - Yiraner - 依然、依然
    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Login(string userName, string password, bool rememberMe, string returnUrl,string code)
    {
    if (Session["ValidateCode"].ToString() != code)
        {
            ModelState.AddModelError("code", "validate code is error");
    return View();
        }
    //此处验证用户名、密码
    if (!ValidateLogOn(userName, password))
        {
    return View();
        }
    //验证成功
        FormsAuthentication.SetAuthCookie(userName, rememberMe);
    if (!String.IsNullOrEmpty(returnUrl))
        {
    return Redirect(returnUrl);
        }
    else
        {
    return RedirectToAction("Index", "Home");
        }
    }

        为实现登录页中,点击图片切换验证码,可以登录页中加入此JS代码实现刷新验证码:

    ASP.net 验证码(C) MVC - Yiraner - 依然、依然
    <script type="text/javascript" src="http://www.cnblogs.com/Scripts/jquery-1.3.2-vsdoc.js"></script>
    <script type="text/javascript">
        $(function() {
        $("#valiCode").bind("click", function() {
    this.src = "../Account/GetValidateCode?time=" + (new Date()).getTime();
            });
    //alert("good");
        });
    </script>

        至此,ASP.NET MVC中已成功实现验证码功能。

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  • 原文地址:https://www.cnblogs.com/zxtceq/p/5166397.html
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