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 = 1;
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(2);
        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) > 0)
        System.Windows.Forms.Application.DoEvents();
}