/// <summary>
        /// 启动 progress dialog.
        /// </summary>
        /// <param name="context">Context.</param>
        /// <param name="msg">Message.</param>
        public static void StartProgressDialog(Activity _activity, string msg, bool canceleable = false)
        {
//			if(progressDialog == null)
            progressDialog = CustomProgressDialog.createDialog(_activity);
            progressDialog.Window.SetGravity(GravityFlags.Center);
            progressDialog.SetMessage(msg);
            progressDialog.Show();
            progressDialog.SetCancelable(canceleable);
        }