[转载]一个C#文件传输模块,支持断点续传

转自：http://www.cnblogs.com/takamachi660/archive/2009/08/06/1540022.html

最近做一个程序需要传送文件,在网上找了好久也没找到好用的方案,于是自己写了一个,与大家分享,希望大家帮忙改进,拍砖欢迎～
文件采取分块发送,每块单独校验,能够保证文件的完整性.同时还提供磁盘缓存功能.
经过实际测试,通过局域网(有线和WiFi)传送一个5G左右的文件取得成功.
最大缺点是CPU占用率过高,测试中发送端(939AMD3000+)达到40%,接收端(双核T9600、939AMD3200+)分别为15%和35%左右.
性能确实还有待改进....
贴出部分代码,其他的放附件里:

VS2008完整项目文件,包括类库和一个简单的Demo:
/Files/takamachi660/SendFileTest_v0.6.rar

=========================

using System;
using log4net;
using System.Collections;
using System.Text;
using System.IO;
using System.Net;
using log4net.Config;
using Chxp.Business;
namespace Chxp.Service
{
   public class FileLib
    {
        #region 属性
        private string fileName = "";
        public string FileName
        {
            get { return fileName; }
            set { fileName = value; }
        }
      
        #endregion  
      
       private static readonly ILog LOG = LogManager.GetLogger(typeof(FileLib));

        #region 文件上传
       
       /// <summary>
       /// 上传文件（自动分割）
       /// </summary>
       /// <param name="filePath">待上传的文件全路径名称(@"E:/FTP/ftproot/20070228DQCK.zip")</param>
       /// <param name="hostURL">服务器的地址</param>
       /// <param name="byteCount">分割的字节大小</param>        
       /// <param name="userID">主机用户ID</param>
       /// <param name="cruuent">当前字节指针</param>
       /// <returns>成功返回"";失败则返回错误信息</returns>
        public string UpLoadFile(string filePath, string hostURL, int byteCount,string userID,long cruuent)
        {
            string tmpURL = hostURL;
            byteCount = byteCount * 1024;
            //http://localhost:8080/fism/app?service=fileupload&beanId=com.cfcc.fism.service.upload.CollFileSaveServiceImpl&action=upload&filename=AI1215900000020051130411.zip&userid=test&npos=333
            //action=length

            System.Net.WebClient WebClientObj = new System.Net.WebClient();
            FileStream fStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            BinaryReader bReader = new BinaryReader(fStream);
            long length = fStream.Length;           
            string sMsg = "版式上传成功";
            string fileName = filePath.Substring(filePath.LastIndexOf('//') + 1);           
            try
            {

                #region 续传处理
                byte[] data;
                if (cruuent > 0)
                {
                    fStream.Seek(cruuent, SeekOrigin.Current);
                }
                #endregion 

                #region 分割文件上传
                for (; cruuent <= length; cruuent = cruuent + byteCount)
                { 
                    if (cruuent + byteCount > length)
                    {
                        data = new byte[Convert.ToInt64((length - cruuent))];
                        bReader.Read(data, 0, Convert.ToInt32((length - cruuent)));
                    }
                    else
                    {
                        data = new byte[byteCount];
                        bReader.Read(data, 0, byteCount);
                    } 
                    try
                    { 
                        LOG.Debug(data); 
                        //***
                        hostURL = tmpURL + "&action=upload" + "&filename=" + fileName + "&userid=" + userID + "&npos=" + cruuent.ToString();
                        byte[] byRemoteInfo = WebClientObj.UploadData(hostURL, "POST", data);
                        string sRemoteInfo = System.Text.Encoding.Default.GetString(byRemoteInfo);

                      //  获取返回信息
                        if (sRemoteInfo.Trim() != "")
                        {
                            sMsg =  sRemoteInfo;
                            break; 
                        }
                    }
                    catch (Exception ex)
                    {
                        sMsg =  ex.ToString();
                        break;
                    }
                #endregion

                }
            }
            catch (Exception ex)
            {
                sMsg = sMsg + ex.ToString(); 
            }
            try
            { 
                bReader.Close();
                fStream.Close();
            }
            catch (Exception exMsg)
            {
                sMsg =  exMsg.ToString();
            } 
            GC.Collect();
            return sMsg;
        } 
        #endregion

        #region 获取文件大小
       /// <summary>
       /// 获取远程服务器文件字节大小
       /// </summary>
       /// <param name="filePath">待上传的文件全路径名称</param>
       /// <param name="hostURL">服务器的地址</param>
       /// <param name="userID">主机用户ID</param>
       /// <returns>远程文件大小</returns>
        public long GetRemoteFileLength(string filePath, string hostURL, string userID)
       {
           long length = 0; 
           System.Net.WebClient WebClientObj = new System.Net.WebClient();  
           string fileName = filePath.Substring(filePath.LastIndexOf('//') + 1); 
           hostURL = hostURL +"&action=length" + "&filename=" + fileName + "&userid=" + userID + "&npos=0" ;
           
           byte[] data = new byte[0];
           byte[] byRemoteInfo = WebClientObj.UploadData(hostURL , "POST", data);
           string sRemoteInfo = System.Text.Encoding.Default.GetString(byRemoteInfo);//主系统没有作异常处理
           try
           {
               length = Convert.ToInt64(sRemoteInfo);
           }
           catch (Exception exx)
           {
               LOG.Error("FileLib类GetRemoteFileLength()中length = Convert.ToInt64(sRemoteInfo)语句异常：" + exx.Message);//我们强制处理异常
               length = 0;
           }
           GC.Collect(); 
           return length; 
       }

       /// <summary>
       /// 获得本地文件字节大小
       /// </summary>
       /// <param name="filePath">本地文件全路径</param>
       /// <returns>本地文件字节大小</returns>
       public long GetLocalFileLength(string filePath)
       {
           long length = 0;
           try
           {
               string fileName = filePath.Substring(filePath.LastIndexOf('//') + 1);
               FileStream s = new FileStream(filePath, FileMode.Open);
               length = s.Length;
               s.Close();
           }
           catch(Exception ex)
           {
               LOG.Error("FileLib类中获取本地文件大小异常："+ex.Message);
           }
           return length; 
       }
        #endregion

       #region 文件下载
       public bool DownLoadFile(string localPath, string hostURL, int byteCount, string userID, long cruuent)
       {
           bool result = true; 
           string tmpURL = hostURL;
          
           byteCount = byteCount * 1024;
           hostURL = tmpURL + "&npos=" + cruuent.ToString();
           
           System.IO.FileStream fs;  
           fs = new FileStream(localPath, FileMode.OpenOrCreate);
           if (cruuent > 0)
           {
               //偏移指针
               fs.Seek(cruuent, System.IO.SeekOrigin.Current); 
           } 

           System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(hostURL);
           if (cruuent > 0)
           {
               request.AddRange(Convert.ToInt32(cruuent));    //设置Range值
           }

           try
           {
               //向服务器请求，获得服务器回应数据流
               System.IO.Stream ns = request.GetResponse().GetResponseStream();

               byte[] nbytes = new byte[byteCount];
               int nReadSize = 0;
               nReadSize = ns.Read(nbytes, 0, byteCount);
              
               while (nReadSize > 0)
               {
                   fs.Write(nbytes, 0, nReadSize);
                   nReadSize = ns.Read(nbytes, 0, byteCount); 
               }
               fs.Close();
               ns.Close();
           }
           catch(Exception ex)
           {
               LOG.Error("下载" + localPath + "的时候失败！" + "原因是:" + ex.Message);
               fs.Close();
               result = false;
           }  
           return result; 
       }
       #endregion 
   }
}