17168ERP/web/App_Script/chksum.ashx

<%@ 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();
        }
    }

    /// <summary>   
    /// 產生圖形驗證碼。   
    /// </summary>   
    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();
        }
    }

    /// <summary>   
    /// 產生圖形驗證碼。   
    /// </summary>   
    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; }
    }

}