ashx与验证码

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Drawing.Drawing2D;

using System.IO;

/// <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)

{

if (length < 1)

{

length = 1;

}

if (length > 10)

{

length = 10;

}

string[] sourceCode = new string[] { "1", "2", "3", "4", "5", "6", "7", "8", "9", "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" };

Random r = new Random(unchecked((int)DateTime.Now.Ticks));

string codes = "";

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

{

int l = r.Next(0, 35);

codes += sourceCode[l];

}

return codes;

}

/// <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 * 15.0), 24);

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();

}

}

/// <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 * 13.0);

}

/// <summary>

/// 得到验证码的高度

/// </summary>

/// <returns></returns>

public static double GetImageHeight()

{

return 22.5;

}

}

====================ashx================

public class ashxGetCode : IHttpHandler

{

public void ProcessRequest(HttpContext context)

{

context.Response.ContentType = "text/plain";

ValidateCode vc = new ValidateCode();

string code =  vc.CreateValidateCode(4);

byte[] result =  vc.CreateValidateGraphic(code);

context.Response.BinaryWrite(result);

}

public bool IsReusable

{

get

{

return false;

}

}

}

=============mvc========

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");   
}