未调用 BackgroundWorker DoWork 函数

Question

我在我的 C# WinForms 应用程序中创建了一个加载表单，该表单会在长时间的进程中显示。我在我的加载表单中添加了一个进度条，我想更新它以向用户提供一些加载反馈。

在我的加载表单代码中，我创建了一个新的 BackgroundWorker 并添加了 DoWork 和 ProgressChanged 事件处理程序。问题是 backgroundWorker_ProgressChanged 没有被调用。我在函数中插入了断点，但它们没有被捕获。

我哪里错了？任何帮助表示赞赏。谢谢

frmLoading:

public frmLoading()
        {
            InitializeComponent();

            //check if bg worker is null
            if (backgroundWorker == null)
            {
                backgroundWorker = new BackgroundWorker();

                backgroundWorker.DoWork += backgroundWorker_DoWork;
                backgroundWorker.ProgressChanged += backgroundWorker_ProgressChanged;

                
            }

            backgroundWorker.WorkerReportsProgress = true;

            //start
            backgroundWorker.RunWorkerAsync();
        }

backgroundWorker_DoWork:

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            for (int i = 1; i <= 100; i++)
            {
                Thread.Sleep(100);
                backgroundWorker.ReportProgress(i);
            }
        }

backgroundWorker_ProgressChanged:

private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            //update value of progress bar
            progressBar1.Value = e.ProgressPercentage;
            //set the text of the progress bar
            this.Text = e.ProgressPercentage.ToString();
        }

Answer 1

以下是使用 Progress<int> 和 Task.Run 执行此操作的方法：

public frmLoading()
{
    InitializeComponent();

    IProgress<int> progress = new Progress<int>(p =>
    {
        //update value of progress bar
        progressBar1.Value = p;
        //set the text of the progress bar
        this.Text = p.ToString();
    });

    Task.Run(async () =>
    {
        for (int i = 1; i <= 100; i++)
        {
            await Task.Delay(TimeSpan.FromSeconds(0.1));
            progress.Report(i);
        }
    });
}

个人比较喜欢微软的Reactive Framework:

public frmLoading()
{
    InitializeComponent();

    Observable
        .Interval(TimeSpan.FromSeconds(0.1))
        .Take(100)
        .ObserveOn(this)
        .Select(p => p + 1)
        .Subscribe(p =>
        {
            //update value of progress bar
            progressBar1.Value = p;
            //set the text of the progress bar
            this.Text = p.ToString();
        });
}

未调用 BackgroundWorker DoWork 函数

BackgroundWorker DoWork function is not being called

c#

multithreading

backgroundworker

winforms

background-thread