asp.net 图片验证码的HtmlHelper

<img id="validateCode" mailto:src='@Url.Action(%22GetValidateCode%22)'/>

<script language="javascript" type="text/javascript">

$(document).ready(function () {

$("#validateCode").bind("click", function () {

var url = $(this).attr("src");

url += "?" + Math.random();

$(this).attr("src", url);

});

});

</script>

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System;

using System.Collections.Generic;

using System.Diagnostics.CodeAnalysis;

using System.Globalization;

using System.Linq.Expressions;

using System.Security.Policy;

using System.Text;

using System.Web;

using System.Web.Mvc;

using System.Web.Mvc.Resources;

using System.Web.Routing;

namespace MvcApplication1

{

public static class ValidateCodeHelper

{

private const string IdPrefix = "validateCode";

private const int Length = 4;

public static MvcHtmlString ValidateCode(this HtmlHelper helper)

{

return ValidateCode(helper, IdPrefix);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper,string id)

{

return ValidateCode(helper, id, Length);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper, string id, int length)

{

return ValidateCode(helper, id, length, null);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper, string id, object htmlAttributes)

{

return ValidateCode(helper, id, Length, htmlAttributes);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper, int length, object htmlAttributes)

{

return ValidateCode(helper, IdPrefix, length, htmlAttributes);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper, object htmlAttributes)

{

return ValidateCode(helper, 4, htmlAttributes);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper, int length)

{

return ValidateCode(helper,length, null);

}

public static MvcHtmlString ValidateCode(this HtmlHelper helper,string id,int length,object htmlAttributes)

{

string finalId = id + "_imgValidateCode";

var tagBuild = new TagBuilder("img");

tagBuild.GenerateId(finalId);

var defaultController = ((Route)RouteTable.Routes["Default"]).Defaults["controller"] + "/";

var controller = HttpContext.Current.Request.Url.Segments.Length == 1

? defaultController

: HttpContext.Current.Request.Url.Segments[1];

tagBuild.MergeAttribute("src", string.Format("/{0}GetValidateCode?length={1}",controller,length));

tagBuild.MergeAttribute("alt", "看不清？点我试试看！");

tagBuild.MergeAttribute("style","cursor:pointer;");

tagBuild.MergeAttributes(AnonymousObjectToHtmlAttributes(htmlAttributes));

var sb = new StringBuilder();

sb.Append("<script language=\"javascript\" type=\"text/javascript\">");

sb.Append("$(document).ready(function () {");

sb.AppendFormat("$(\"#{0}\").bind(\"click\", function () {{", finalId);

//sb.Append("$(this).attr(\"style\", \"cursor:pointer;\");");

sb.Append("var url = $(this).attr(\"src\");");

sb.Append("url += \"&\" + Math.random();");

sb.Append("$(this).attr(\"src\", url);");

sb.Append("});");

sb.Append("});");

sb.Append("</script>");

return MvcHtmlString.Create(tagBuild+sb.ToString());

}

public static RouteValueDictionary AnonymousObjectToHtmlAttributes(object htmlAttributes)

{

var result = new RouteValueDictionary();

if (htmlAttributes != null)

{

foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(htmlAttributes))

{

result.Add(property.Name.Replace('_', '-'), property.GetValue(htmlAttributes));

}

}

return result;

}

}

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.IO;

using System.Drawing.Imaging;

namespace MvcApplication1

{

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)

{

var randMembers = new int[length];

var validateNums = new int[length];

var validateNumberStr = "";

//生成起始序列值

var seekSeek = unchecked((int)DateTime.Now.Ticks);

var seekRand = new Random(seekSeek);

var beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);

var seeks = new int[length];

for (var i = 0; i < length; i++)

{

beginSeek += 10000;

seeks[i] = beginSeek;

}

//生成随机数字

for (var i = 0; i < length; i++)

{

var rand = new Random(seeks[i]);

var pownum = 1 * (int)Math.Pow(10, length);

randMembers[i] = rand.Next(pownum, Int32.MaxValue);

}

//抽取随机数字

for (var i = 0; i < length; i++)

{

var numStr = randMembers[i].ToString();

var numLength = numStr.Length;

var rand = new Random();

var numPosition = rand.Next(0, numLength - 1);

validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));

}

//生成验证码

for (var i = 0; i < length; i++)

{

validateNumberStr += validateNums[i].ToString();

}

return validateNumberStr;

}

/// <summary>

/// 创建验证码的图片

/// </summary>

/// <param name="validateCode">验证码</param>

public byte[] CreateValidateGraphic(string validateCode)

{

var image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);

var g = Graphics.FromImage(image);

try

{

//生成随机生成器

var 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++)

{

var x1 = random.Next(image.Width);

var x2 = random.Next(image.Width);

var y1 = random.Next(image.Height);

var 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));

string[] fontName = { "华文新魏", "宋体", "圆体", "黑体", "隶书" };

var font = new Font(fontName[new Random().Next(0, validateCode.Length)], 12, (FontStyle.Bold | FontStyle.Italic));

var 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 (var i = 0; i < 100; i++)

{

var x = random.Next(image.Width);

var 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

var stream = new MemoryStream();

image.Save(stream, ImageFormat.Jpeg);

//输出图片流

return 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 23;

}

}

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace MvcApplication1

{

public class BaseController:Controller

{

public ActionResult GetValidateCode(int length)

{

var vCode = new ValidateCode();

var code = vCode.CreateValidateCode(length);

Session["ValidateCode"] = code;

var bytes = vCode.CreateValidateGraphic(code);

return File(bytes, @"image/gif");

}

protected string GetValidateCode()

{

return Session["ValidateCode"].ToString();

}

}

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

using System.Web.Security;

namespace MvcApplication1.Controllers

{

public class HomeController :BaseController

{

public ActionResult Index()

{

ViewBag.Message = "Welcome to ASP.NET MVC!";

return View();

}

public ActionResult About()

{

var code = GetValidateCode();

return View();

}

}

}

@using MvcApplication1

@{

ViewBag.Title = "About Us";

}

<h2>About</h2>

<p>

Put content here.

</p>

@Html.ValidateCode()