动态调用WebService-获取天气

string url = "http://www.webxml.com.cn/WebServices/WeatherWebService.asmx";
???????????string[] args = new string[1];
???????????args[0] = "上海";
???????????object ob = WSHelper.InvokeWebService(url, "getWeatherbyCityName", args);
???????????string[] str = (string[])ob;
???????????StringBuilder sb = new StringBuilder();
???????????if (ob == null)
???????????{
???????????????sb.AppendLine("暂无信息");
???????????}
???????????else
???????????{
???????????????foreach (var item in str)
???????????????{
???????????????????sb.AppendLine(item);
???????????????}
???????????}
???????????return sb.ToString();