<%@ WebHandler Language="C#" Class="chksum" %>
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Web;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Web.SessionState;
public class chksum : IHttpHandler, IRequiresSessionState
{
public void ProcessRequest(HttpContext context)
{
string sCode = string.Empty;
//清除該頁輸出緩存，設置該頁無緩存
context.Response.Buffer = true;
context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
context.Response.Expires = 0;
context.Response.CacheControl = "no-cache";
context.Response.AppendHeader("Pragma", "No-Cache");
//將驗證碼圖片寫入記憶體流，並將其以 "image/Png" 格式輸出
MemoryStream oStream = new MemoryStream();
try
{
//Randomize()
//Dim clen As New Random
CreateValidateCodeImage(ref oStream, ref sCode, 4, 120, 36, 20);
//Response.Cookies("chknum").Value = sCode
//Response.Cookies("chknum").Expires = DateAdd("D", 1, Today)
context.Session["chknum"] = sCode;
context.Response.ClearContent();
context.Response.ContentType = "image/Png";
context.Response.BinaryWrite(oStream.ToArray());
}
finally
{
//釋放資源
oStream.Dispose();
}
}
///
/// 產生圖形驗證碼。
///
public Bitmap CreateValidateCodeImage(ref string Code, int CodeLength, int Width, int Height, int FontSize)
{
string sCode = string.Empty;
//顏色列表，用於驗證碼、噪線、噪點
Color[] oColors = {
System.Drawing.Color.Black,
System.Drawing.Color.DimGray,
System.Drawing.Color.Red,
System.Drawing.Color.IndianRed,
System.Drawing.Color.OliveDrab,
System.Drawing.Color.OrangeRed,
System.Drawing.Color.DarkOrange,
System.Drawing.Color.DarkOliveGreen,
System.Drawing.Color.Brown,
System.Drawing.Color.BlueViolet,
System.Drawing.Color.DarkBlue
};
//字體列表，用於驗證碼
string[] oFontNames = {
"Times New Roman",
"MS Mincho",
"Book Antiqua",
"Gungsuh",
"PMingLiU",
"Impact"
};
//驗證碼的字元集，去掉了一些容易混淆的字元
char[] oCharacter = {
'2',
'3',
'4',
'5',
'6',
'8',
'9',
'A',
'B',
'C',
'D',
'E',
'F',
'G',
'H',
'J',
'K',
'L',
'M',
'N',
'P',
'R',
'S',
'T',
'W',
'X',
'Y'
};
Random oRnd = new Random(Guid.NewGuid().GetHashCode());
Bitmap oBmp = null;
Graphics oGraphics = null;
int N1 = 0;
System.Drawing.Point oPoint1 = default(System.Drawing.Point);
System.Drawing.Point oPoint2 = default(System.Drawing.Point);
string sFontName = null;
Font oFont = null;
Color oColor = default(Color);
//生成驗證碼字串
for (N1 = 0; N1 < CodeLength ; N1++)
{
sCode += oCharacter[oRnd.Next(oCharacter.Length)];
}
double scale = 1.5;
oBmp = new Bitmap((int)(Width*scale), (int)(Height*scale));
oGraphics = Graphics.FromImage(oBmp);
oGraphics.Clear(System.Drawing.Color.White);
try
{
FontStyle[] fs = { FontStyle.Italic , FontStyle.Bold, FontStyle.Regular};
for (N1 = 0; N1 <= sCode.Length - 1; N1++)
{
//畫驗證碼字串
sFontName = oFontNames[oRnd.Next(oFontNames.Length)];
oFont = new Font(sFontName, FontSize, fs[oRnd.Next(fs.Length)]);
oColor = oColors[oRnd.Next(oColors.Length)];
oGraphics.DrawString(sCode[N1].ToString(), oFont, new SolidBrush(oColor), Convert.ToSingle(N1) * FontSize + 16, Convert.ToSingle(4));
}
for (N1 = 0; N1 <= 5; N1++)
{
//畫噪線
oPoint1.X = oRnd.Next(Width);
oPoint1.Y = oRnd.Next(Height);
oPoint2.X = oRnd.Next(Width);
oPoint2.Y = oRnd.Next(Height);
oColor = oColors[oRnd.Next(oColors.Length)];
oGraphics.DrawLine(new Pen(oColor), oPoint1, oPoint2);
}
for (int i = 0; i <= 600; i++)
{
//畫噪點
int x = oRnd.Next(oBmp.Width);
int y = oRnd.Next(oBmp.Height);
Color clr = oColors[oRnd.Next(oColors.Length)];
oBmp.SetPixel(x, y, clr);
}
Code = sCode;
return oBmp;
}
finally
{
oGraphics.Dispose();
}
}
///
/// 產生圖形驗證碼。
///
public void CreateValidateCodeImage(ref MemoryStream MemoryStream, ref string Code, int CodeLength, int Width, int Height, int FontSize)
{
Bitmap oBmp = null;
oBmp = CreateValidateCodeImage(ref Code, CodeLength, Width, Height, FontSize);
try
{
oBmp.Save(MemoryStream, ImageFormat.Png);
}
finally
{
oBmp.Dispose();
}
}
public bool IsReusable
{
get { return false; }
}
}