简单的验证码CS代码

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.SessionState;

namespace ZitCms1127Exams.images
{
///

/// Handler1 的摘要说明
///

public class Handler1 : IHttpHandler,IRequiresSessionState
{
private Random random = new Random();

private int length=6;

private char[] chars =
{
'0', '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', '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'
};

private string makeChars()
{
var arr = new char[length];
for (int i = 0; i < length; i++)
{
arr[i] = chars[random.Next(chars.Length)];
}

return new string(arr);
}

public void ProcessRequest(HttpContext context)
{

var capcha = makeChars();
context.Session["capcha"] = capcha;

var bytes = createImage(capcha);

context.Response.ContentType = "image/jpeg";
context.Response.BinaryWrite(bytes);

//var fileNameWithoutExt = random.Next(1, 5);
//var fileName = fileNameWithoutExt + ".jpg";
//context.Response.WriteFile(fileName);
//context.Response.BinaryWrite();
}

private byte[] createImage(string capcha)
{
var img = new Bitmap(20 * length, 30);
var gh = Graphics.FromImage(img);
gh.FillRectangle(Brushes.BlanchedAlmond, 0, 0, 20*length, 30);
gh.DrawString(capcha, new Font("新宋体", 20, GraphicsUnit.Pixel), Brushes.BlueViolet, 3, 3);
gh.DrawLine(Pens.Teal, 0, 30, 20*length, 0);

var ms = new MemoryStream();
img.Save(ms, ImageFormat.Jpeg);

var bytes = ms.ToArray();

ms.Close();
ms.Dispose();

gh.Dispose();
img.Dispose();

return bytes;
}

public bool IsReusable
{
get
{
return false;
}
}

}
}