using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;

namespace NetWorkHardNew.GlobalAshx
{
	/// <summary>
	/// DownFile 的摘要说明
	/// </summary>
	public class DownFile : IHttpHandler
	{

		public void ProcessRequest(HttpContext context)
		{
			HttpFileCollection files = context.Request.Files;
			string FilePath = context.Server.UrlDecode(context.Request.QueryString["FilePath"]);
			string FileName = context.Server.UrlDecode(context.Request.QueryString["FileName"]);
			if (FilePath == "") return;
			FilePath = AppDomain.CurrentDomain.BaseDirectory + FilePath;
            string ext = Path.GetExtension(FilePath);
            if (ext == ".aspx" || ext == ".config" || ext == ".dll" || FilePath == "/Setup.ini" || FilePath == "Setup.ini")
            {
                context.Response.End();
                return;
            }
			context.Response.Clear();
			context.Response.ClearHeaders();
			context.Response.Buffer = true;
			context.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.GetEncoding("utf-8")));
			context.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312"); //设置输出流为简体中文
			context.Response.ContentType = "application/octet-stream";
			if (Path.GetExtension(FileName) == ".doc") context.Response.ContentType = "application/ms-word";
			if (Path.GetExtension(FileName) == ".xls") context.Response.ContentType = "application/ms-excel";
            if (Path.GetExtension(FileName) == ".pdf") context.Response.ContentType = "application/pdf";
			if (System.IO.File.Exists(FilePath) == true)
			{
				FileInfo fi = new FileInfo(FilePath);
				FileStream fs = null;
				byte[] buffer = new Byte[10000];
				int length;
				long dataToRead;
				try
				{
					fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
					context.Response.AppendHeader("Content-Length", fs.Length.ToString());
					dataToRead = fs.Length;
					while (dataToRead > 0)
					{
						if (context.Response.IsClientConnected)
						{
							length = fs.Read(buffer, 0, 10000);
							context.Response.OutputStream.Write(buffer, 0, length);
							context.Response.Flush();
							buffer = new Byte[10000];
							dataToRead = dataToRead - length;
						}
						else
						{
							dataToRead = -1;
						}
					}

				}
				catch { }
				finally
				{
					if (fs != null)
					{
						fs.Close();
					}
					context.Response.End();
				}

			}


		}


		public bool IsReusable
		{
			get
			{
				return false;
			}
		}
	}
}