public DataTable ReturnDataTable(string cmdText)
        {
            frmWait frmW = new frmWait();
            frmW.Show();
            try
            {
                wcfHost = new ServiceReference1.Service1Client();

                DataTable dt = wcfHost.ReturnDataTable(cmdText);

                return dt;
                frmW.Close();
            }
            catch
            {
                frmW.Close();
                MessageBox.Show("请检查与服务器的连接是否正常！", "获取数据失败", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return null;
            }
            finally
            {
                DisposeWcfHost(wcfHost);
                
            }
        }