C#WebClient常见用法

System.Net.WebClient.DownloadFile(Uri address, String fileName)

namespace：System.Net

参数：

address：The URI from which to download data.
fileName：The name of the local file that is to receive the data.

eg:

 /// <summary>
 /// 保存文件到本地
 /// </summary>
 /// <param name="filePath">uri</param>
 /// <param name="folderPath">localDir</param>
 /// <param name="localFilePath">folderPath+fileName</param>
 public void SaveDownFile(string filePath, string folderPath, string localFilePath)
 {
     try
     {
         if (!Directory.Exists(folderPath))
         {
             Directory.CreateDirectory(folderPath);
         }
         WebClient DownFile = new WebClient();
         DownFile.DownloadFile(filePath, localFilePath);
         logger.WriteSystemLog(LogLevel.Const, "successfully saveDownFile：" + localFilePath);
     }
     catch (Exception ex)
     {
         logger.WriteExceptionLog(ex, " saveDownFile Exception: httpUrl=" + filePath);
     }
 }

 public static long userId = ;
 public static string userCode;
 public static string token;
 public static string clientIP;
 // 单点登录
 protected void sso()
 {
     clientIP = GetClientIP();// local IP
     userId = GetUserId();
     userCode = GetUserCode();
     token = sendMessage(userId, userCode, clientIP);// 发送验证消息

     if (!string.IsNullOrEmpty(token))
     {
         delayTime();
         simLogin(token);
     }
 }

 // 登录
 private void simLogin(string token)
 {
     var url = string.Format("http://192.168.12.250:8900/Login?userId={0}&clientIP={1}&token={2}", userCode, clientIP, token);
     WebClient wc = new WebClient();
     byte[] ret = wc.DownloadData(url);
 }

 private void delayTime(double secend)
 {
     DateTime tempTime = DateTime.Now;
     while (tempTime.AddSeconds(secend).CompareTo(DateTime.Now) > )
         System.Windows.Forms.Application.DoEvents();
 }