最忌你在一个文档管理系统，包裹文件上传下载等。
http://blog.csdn.net/pmy_c_l/article/details/73743843
官方链接:https://msdn.microsoft.com/zh-cn/library/system.io.filestream.read.aspx
???????/// <summary> ???????/// 读取本地文件上传到服务器 ???????/// </summary> ???????/// <param name="localfilepath">本地文件路径</param> ???????/// <param name="serverpath">服务器存储路径</param> ???????public void ReadFile(string localfilepath, string serverpath) ???????{ ???????????//string filepath = "C:\xxx";//文件上传本地地址; ???????????//string serverpath = HttpContext.Current.Server.MapPath("../File/" + fileName); //保存在服务器上的路径 ???????????????????????try ???????????{ ???????????????FileInfo fs = new FileInfo(localfilepath); ???????????????string fileName = fs.Name; ?//获取文件名 ???????????????using (FileStream fsRead = new FileStream(localfilepath, FileMode.Open)) ???????????????{ ???????????????????using (FileStream fsWrite = new FileStream(serverpath, FileMode.OpenOrCreate)) ???????????????????{//自定义数组的长度 ???????????????????????byte[] bytes = new byte[fsRead.Length]; ???????????????????????//当没有读取到文件的末尾的时候就需要循环读取 ???????????????????????while (fsRead.Position < fsRead.Length) ???????????????????????{//读取的时候position属性会自动变化，记住当前读取到的位置，以字节为单位 ???????????????????????????//count可以获取当前具体读取到的字节数 ???????????????????????????int count = fsRead.Read(bytes, 0, bytes.Length); ???????????????????????????if (count == 0) { break; } ???????????????????????????????????????????????????} ???????????????????????//写入 ???????????????????????fsWrite.Write(bytes, 0, fsRead.Length); //只需要写入读取到的字节数就可以了 ???????????????????} ???????????????} ????????????} ???????????catch (Exception e) ???????????{ ???????????????throw e; ???????????} ???????}.net 文件上传到服务器【转】
原文地址：http://www.cnblogs.com/yuan-jiang/p/7516260.html