Task task =  new Task(() =>
            {
                //開啟加載動畫跨線程更新UI<Mask是指的遮罩層動畫>
                this.Dispatcher.Invoke(() => {
                    Mask.Visibility = Visibility.Visible;
                });
                //此處為查詢方法例如SelectAll()
                
            });
             //線程啟動
             task.Start(); 
           //線程結束
            task.ContinueWith((a) =>
            {
                //關閉加載動畫
                this.Dispatcher.Invoke(() => {//控件數據更新效果寫到處
                    Mask.Visibility = Visibility.Collapsed;
                });
            });