NetworkCredential credential = new NetworkCredential(this.proxyUser, this.proxyPassword, this.proxyDomain);
    WebProxy proxy = new WebProxy();    proxy.Address = new Uri(this.proxyServer);
    proxy.Credentials = credential;    uploadObj.Proxy = proxy;注:uploadObj Web服务对象;this.ProxyUser代理用户名称;this.proxyPassword代理用户密码;this.proxyDomain代理域名;this.proxyServer代理服务器地址;这个this.proxyServer应该是IP地址还是带有 http://IP 的字符串呢;this.proxyDomain应该写什么,是局域网的域名还是 当前客户机的计算机名称??