async void GetStringList(object sender, RoutedEventArgs e)
{
List <string> ls = await AtTest.GetStringList();
StringBuilder sb = new StringBuilder();
sb.AppendFormat("调用成功，共有{0}个字符串：\r\n", ls.Count);
foreach (string item in ls)
{
sb.AppendLine(item);
}
_tbInfo.Text = sb.ToString();
}