使用WebClient下载文件到本地目录

利用WebClient实现下载文件

调用

 string url = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1494677827304&di=8e8aaf1a717ae37b73b772ee4728c7ea&imgtype=0&src=http%3A%2F%2Fscimg.jb51.net%2Fallimg%2F141123%2F10-1411231F92W16.jpg";
            string fileName = FileHandler.DownloadFile(url);
            if (!String.IsNullOrEmpty(fileName))
            {
                Console.WriteLine("文件下载成功，文件名称：" + fileName);
            }
            else
            {
                Console.WriteLine("文件下载失败");
            }
            Console.ReadLine();

 /// <summary>
    /// 文件处理类
    /// </summary>
    public static class FileHandler
    {
        /// <summary>
        /// 文件下载目录
        /// </summary>
        private static string _directory = Path.Combine("C:\","Down\");//下载的文件存放于c盘Down文件夹下面

        /// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="url">下载地址</param>
        /// <returns>文件名称</returns>
        public static string DownloadFile(string url)
        {
            try
            {
                string fileName = CreateFileName(url);
                if (!Directory.Exists(_directory))
                {
                    Directory.CreateDirectory(_directory);
                }
                bool flag = url.StartsWith("http://") || url.StartsWith("https://");
                if (flag)
                {
                    WebClient client = new WebClient();
                    client.DownloadFile(url, _directory + fileName);
                }                             
                return fileName;
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>
        /// 创建文件名称
        /// </summary>
        public static string CreateFileName(string url)
        {
            string fileName = "";
            string fileExt = url.Substring(url.LastIndexOf(".")).Trim().ToLower();
            Random rnd = new Random();
            fileName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + rnd.Next(10, 99).ToString() + fileExt;
            return fileName;
        }
    }
    }