用web request 下载档案
public void DownloadPanelPrice(string url, string fileName){try{//如果要透proxy且需要密需下列三行代System.Net.WebProxy proxy = new System.Net.WebProxy("proxyIP:port");proxy.Credentials = new System.Net.NetworkCredential("", "密", "域");WebRequest.DefaultWebProxy = proxy;//url="http://localhost/Data/abc.xls";WebRequest myWebRequest = WebRequest.Create(url);WebResponse myWebResponse = myWebRequest.GetResponse();Stream receiveStream = myWebResponse.GetResponseStream();//如果下的案名固定先除，再入，否情而定File.Delete(fileName);FileStream fs = new FileStream(fileName, FileMode.CreateNew);try{while (true){//一byte, 一byteint i = receiveStream.ReadByte();if (i == -1){break;}fs.WriteByte(Convert.ToByte(i));}}finally{fs.Close();myWebResponse.Close();}}catch (Exception ex){throw ex;}finally{WebRequest.DefaultWebProxy = null;}}