实现断点续传下载
string StrFileName = "c://123.zip"; // 定义文件名称 string StrUrl = "http://pan.baidu.com//123.zip"; // 定义网络服务器地址 //打开上次下载的文件或新建文件 long lStartPos = 0; System.IO.FileStream fs; if (System.IO.File.Exists(StrFileName)) { fs = System.IO.File.OpenWrite(StrFileName); lStartPos = fs.Length; fs.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针 } else { fs = new System.IO.FileStream(StrFileName, System.IO.FileMode.Create); lStartPos = 0; } //打开网络连接 try { System.Net.HttpWebRequest request = (System.Net.HttpWebRequest) System.Net.HttpWebRequest.Create(StrUrl); if (lStartPos > 0) request.AddRange((int)lStartPos); //设置Range值 //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[512]; int nReadSize = 0; nReadSize = ns.Read(nbytes, 0, 512); while (nReadSize > 0) { fs.Write(nbytes, 0, nReadSize); nReadSize = ns.Read(nbytes, 0, 512); } fs.Close(); ns.Close(); Console.WriteLine("下载完成"); } catch (Exception ex) { fs.Close(); Console.WriteLine("下载过程中出现错误:" + ex.ToString()); }