C＃Backgroundworker没有报告进度

Question

离开这个...... https://www.codeproject.com/Articles/841751/MultiThreading-Using-a-Background-Worker-Csharp，我试图让我的程序在后台单独的BackGroundWorker上做一些工作。该操作非常有效，但myWorker_ProgressChanged在lbl_status_totalFilesNotCurrent.Content foreach循环myWorker_DoWork内调用时未更新标签sendingWorker.ReportProgress(cnt);的例外我无法弄清楚为什么这部分根据codeproject示例不起作用。

跟进问题...后台工作者是这类任务的首选方法，还是我应该使用任务？ https://docs.microsoft.com/en-us/dotnet/standard/parallel-programming/task-based-asynchronous-programming。我开始意识到后台工作者已被弃用。

private BackgroundWorker myWorker = new BackgroundWorker();

    public MainWindow()
    {
        InitializeComponent();
        currentUser.name = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
        lbl_IndProj.MouseEnter += new MouseEventHandler(changeFontColor);
        lbl_IndProj.MouseLeave += new MouseEventHandler(resetFontColor);

        myWorker.DoWork += new DoWorkEventHandler(myWorker_DoWork);
        myWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(myWorker_RunWorkerCompleted);
        myWorker.ProgressChanged += new ProgressChangedEventHandler(myWorker_ProgressChanged);
        myWorker.WorkerReportsProgress = true;
        myWorker.WorkerSupportsCancellation = true;
    }

    private void MenuItem_Click(object sender, RoutedEventArgs e)
    {
        if (!myWorker.IsBusy)
        {
            myWorker.RunWorkerAsync(currentIndex);
        }
    }

    protected void myWorker_DoWork(object sender, DoWorkEventArgs e)
    {
        BackgroundWorker sendingWorker = (BackgroundWorker)sender;
        Index ci = (Index)e.Argument;
        int cnt = 0;
        foreach (KeyValuePair<int, Project> project in currentIndex.projects)
        {
            foreach (KeyValuePair<int, IndexedDirectory> directory in project.Value.IndexedDirectories)
            {
                foreach (KeyValuePair<int, IndexedFile> indexedfile in directory.Value.IndexedFiles)
                {
                    try
                    {
                        List<IndexedFile> ood = currentIndex.getOutOfDateIndexedFiles();
                        if (ood.Contains(indexedfile.Value))
                        {
                            cnt++;
                            indexedfile.Value.extractInfo();
                            lbl_status.Content = indexedfile.Value.LongName;
                            sendingWorker.ReportProgress(cnt);
                        }
                    }
                    catch { }
                }
            }
        }
    }

    protected void myWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        lbl_status_totalFiles.Content = currentIndex.getAllIndexedFiles().Count().ToString();
        lbl_status_totalFilesNotCurrent.Content = currentIndex.getOutOfDateIndexedFiles().Count().ToString();
    }

        protected void myWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        int cnt = e.ProgressPercentage;
        int report = currentIndex.getOutOfDateIndexedFiles().Count() - cnt;
        lbl_status_totalFilesNotCurrent.Content = report.ToString();
    }