如何在CancelAsync后启动BackgroundWorker

我在UserControls中使用backgroundworker，我通过单击按钮加载到面板中。我在一个UC中点击CancelAsync BW，然后我去另一个UC。当我想回到以前的UС(我已经取消了BW)，我总是进入RunWorkerCompleted事件。

我已经尝试在UC构造函数中重新初始化BW:

bgrWorker = new BackgroundWorker
        {
            WorkerSupportsCancellation = true,
            WorkerReportsProgress = true
        };
        bgrWorker.DoWork += DoWork;
        bgrWorker.ProgressChanged += ProgressChanged;
        bgrWorker.RunWorkerCompleted += RunWorkerCompleted;
        btnStop.Click += StopWorker;

但是行不通。

DoWork事件代码:

System.Threading.Tasks.Parallel.For(0, _list.Count, num =>
            {
                if (bgrWorker.CancellationPending)
                {
                    e.Cancel = true;
                }
                else
                {
                    _splittedList.Add(FindMiddle.Find(_list[num], 20));
                    bgrWorker.ReportProgress(0);
                }
            });