C#FileStream实现多线程断点续传-创新互联

一、前言

公司主营业务：成都网站设计、做网站、移动网站开发等业务。帮助企业客户真正实现互联网宣传，提高企业的竞争能力。创新互联是一支青春激扬、勤奋敬业、活力青春激扬、勤奋敬业、活力澎湃、和谐高效的团队。公司秉承以“开放、自由、严谨、自律”为核心的企业文化，感谢他们对我们的高要求，感谢他们从不同领域给我们带来的挑战，让我们激情的团队有机会用头脑与智慧不断的给客户带来惊喜。创新互联推出西林免费做网站回馈大家。

       网上有许多的多线程断点续传操作，但总是写的很云里雾里，或者写的比较坑长。由于这几个月要负责公司的在线升级项目，所以正好顺便写了一下

代码如下：

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;

namespace TestCenter
{
 class Program
 {
  static void Main(string[] args)
  {
   string LocalSavePath = @"E:\Test\TestFile\Local\1.msi"; //本地目标文件路径

   FileInfo SeverFilePath = new FileInfo(@"E:\Test\TestFile\Server\1.msi"); //服务器待文件路径
   long FileLength = SeverFilePath.Length; //待下载文件大小


   Console.WriteLine("Start Configuration");
   int PackCount = 0; //初始化数据包个数

   long PackSize = 1024000; //数据包大小

   if (FileLength % PackSize > 0)
   {
    PackCount = (int)(FileLength / PackSize) + 1;
   }

   else
   {
    PackCount = (int)(FileLength / PackSize);
   }


   Console.WriteLine("Start Recieve");
   var tasks = new Task[PackCount]; //多线程任务

   for (int index = 0; index < PackCount; index++)
   {


    int Threadindex = index; //这步很关键，在Task()里的绝对不能直接使用index
    var task = new Task(() =>
    {
     string tempfilepath = @"E:\Test\TestFile\Temp\" + "QS_" + Threadindex + "_" + PackCount; //临时文件路径

     using (FileStream tempstream = new FileStream(tempfilepath, FileMode.Create, FileAccess.Write, FileShare.Write))
     {
      int length = (int)Math.Min(PackSize, FileLength - Threadindex * PackSize);

      var bytes = GetFile(Threadindex*PackCount, length);

      tempstream.Write(bytes, 0, length);
      tempstream.Flush();
      tempstream.Close();
      tempstream.Dispose();
     }
    });
    tasks[Threadindex] = task;
    task.Start();
   }

   Task.WaitAll(tasks); //等待所有线程完成
   Console.WriteLine("Recieve End");


   //检测有哪些数据包未下载
   Console.WriteLine("Start Compare");
   DirectoryInfo TempDir = new DirectoryInfo(@"E:\Test\TestFile\temp"); //临时文件夹路径
   List Comparefiles = new List();

   for (int i = 0; i < PackCount; i++)
   {
    bool hasfile = false;
    foreach (FileInfo Tempfile in TempDir.GetFiles())
    {
     if (Tempfile.Name.Split('_')[1] == i.ToString())
     {
      hasfile = true;
      break;
     }
    }
    if (hasfile == false)
    {
     Comparefiles.Add(i.ToString());
    }
   }

   //最后补上这些缺失的文件
   if (Comparefiles.Count > 0)
   {
    foreach (string com_index in Comparefiles)
    {
     string tempfilepath = @"E:\Test\TestFile\Temp\" + "QS_" + com_index+ "_" + PackCount;
     using (FileStream Compstream = new FileStream(tempfilepath, FileMode.Create, FileAccess.Write, FileShare.Write))
     {
      int length = (int)Math.Min(PackSize, FileLength - Convert.ToInt32(com_index) * PackSize);
      var bytes = GetFile(Convert.ToInt32(com_index)*PackCount, length);
      Compstream.Write(bytes, 0, length);
      Compstream.Flush();
      Compstream.Close();
      Compstream.Dispose();
     }
    }

   }
   Console.WriteLine("Compare End");


   //准备将临时文件融合并写到1.msi中
   Console.WriteLine("Start Write");
   using (FileStream writestream = new FileStream(LocalSavePath, FileMode.Create, FileAccess.Write, FileShare.Write))
   {
    foreach (FileInfo Tempfile in TempDir.GetFiles())
    {
     using (FileStream readTempStream = new FileStream(Tempfile.FullName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
     {
      long onefileLength = Tempfile.Length;
      byte[] buffer = new byte[Convert.ToInt32(onefileLength)];
      readTempStream.Read(buffer, 0, Convert.ToInt32(onefileLength));
      writestream.Write(buffer, 0, Convert.ToInt32(onefileLength));
     }
    }
    writestream.Flush();
    writestream.Close();
    writestream.Dispose();
   }
   Console.WriteLine("Write End");



   //删除临时文件
   Console.WriteLine("Start Delete Temp Files");
   foreach (FileInfo Tempfile in TempDir.GetFiles())
   {
    Tempfile.Delete();
   }
   Console.WriteLine("Delete Success");
   Console.ReadKey();
  }


  //这个方法可以放到Remoting或者WCF服务中去，然后本地调用该方法即可实现多线程断点续传
  public static byte[] GetFile(int start, int length)
  {
   string SeverFilePath = @"E:\Test\TestFile\Server\1.msi";
   using (FileStream ServerStream = new FileStream(SeverFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 1024*80, true))
   {
    byte[] buffer = new byte[length];
    ServerStream.Position = start;
    //ServerStream.Seek(start, SeekOrigin.Begin);
    ServerStream.Read(buffer, 0, length);
    return buffer;
   }
  }
 }
}

另外有需要云服务器可以了解下创新互联scvps.cn，海内外云服务器15元起步，三天无理由+7*72小时售后在线，公司持有idc许可证，提供“云服务器、裸金属服务器、高防服务器、香港服务器、美国服务器、虚拟主机、免备案服务器”等云主机租用服务以及企业上云的综合解决方案，具有“安全稳定、简单易用、服务可用性高、性价比高”等特点与优势，专为企业上云打造定制，能够满足用户丰富、多元化的应用场景需求。

文章标题：C#FileStream实现多线程断点续传-创新互联
文章来源：http://bzwzjz.com/article/diidph.html