使用WebClient 进行下载

 WebClient webClick = new WebClient();
            webClick.DownloadFile("https://bcs.duapp.com/myresumedemo/%E7%96%AF%E7%8B%82%E7%9A%84%E7%A8%8B%E5%BA%8F%E5%91%98.rar", "疯狂的程序员.rar");