C＃WPF正在运行的后台工作程序正在退出的应用程序会更新对话框

Question

我的问题与此类似，除了我使用BackgroundWorker而不是WorkflowRuntime之外，我的代码设置几乎相同。 （答案似乎对我不起作用）

过去我使用过Application.Current.Shutdown(); 在MainWindow的关闭事件中，但是我希望通过适当地处理此已成为静态资源的窗口，也许不需要。

问题是，如果我在所有后台任务终止后通过关闭MainWindow退出，则一个空的BackgroundDialog保持打开状态。

public partial class BackgroundDialog : Window
{
    private static BackgroundDialog _Dialog = new BackgroundDialog();
    private static UIElementCollection TasksView { get { return _Dialog.BackgroundList.Children; } }

    public static void Add(BackgroundItem item)
    {
        if (TasksView.Count == 0)
        {
            _Dialog.Show();
        }
        TasksView.Add(item);
    }

    public static void Remove(BackgroundItem item)
    {
        TasksView.Remove(item);
        if (TasksView.Count == 0)
        {
            if (_Release)
            {
                FinishRelease();
            }
            else
            {
                _Dialog.Hide();
            }
        }
    }
    private static bool _Release = false;
    private static void FinishRelease()
    {
        // FinishRelease may be called from a BackgroundWorker thread finishing
        // This results in _Dialog.Close() not behaving as expected
        // For more details: https://stackoverflow.com/questions/5659930/wpf-window-not-closing
        _Dialog.Dispatcher.Invoke(DispatcherPriority.Normal, new Action(() =>
        {
            _Dialog.Close();
            _Dialog = null;
        }));
    }

    public static void Release(EventArgs e)
    {
        _Release = true;
        if (TasksView.Count == 0)
        {
            FinishRelease();
        }
        else foreach (BackgroundItem Task in TasksView)
        {
            Task.Abort();
        }
    }
}

public partial class BackgroundItem : UserControl
{
    public delegate void TaskHandler(BackgroundWorker Worker);

    public interface IBackgroundTask
    {
        bool IsIndeterminate { get; }
        int MaxProgress { get; }
        string Title { get; }
        string Description(int progress);
        TaskHandler Exec { get; }
    }

    private BackgroundWorker Worker;

    public BackgroundItem(IBackgroundTask task)
    {
        InitializeComponent();

        Title.Text = task.Title;
        Description.Text = task.Description(0);

        Progress.Value = 0;
        Progress.Minimum = 0;
        Progress.Maximum = task.MaxProgress;
        Progress.IsIndeterminate = task.IsIndeterminate;

        BackgroundDialog.Add(this);

        Worker = new BackgroundWorker()
        {
            WorkerReportsProgress = true,
            WorkerSupportsCancellation = true,
        };
        Worker.DoWork += (object sender, DoWorkEventArgs e) =>
        {
            task.Exec?.Invoke(Worker);
        };
        Worker.RunWorkerCompleted += (object sender, RunWorkerCompletedEventArgs e) =>
        {
            BackgroundDialog.Remove(this);
        };
        Worker.ProgressChanged += (object sender, ProgressChangedEventArgs e) =>
        {
            Progress.Value = e.ProgressPercentage;
            Description.Text = task.Description(e.ProgressPercentage);
        };
        Worker.RunWorkerAsync();

        Stop.Click += (object sender, RoutedEventArgs e) =>
        {
            Abort();
        };
    }

    public void Abort()
    {
        Worker.CancelAsync();
        Stop.IsEnabled = false;
        StopText.Text = "Stopping";
    }
}

public partial class MainWindow : Window
{
    private class MyTask : BackgroundItem.IBackgroundTask
    {
        public bool IsIndeterminate => true;
        public int MaxProgress => 100;
        public string Title => "I'm Counting";
        public BackgroundItem.TaskHandler Exec => (BackgroundWorker Worker) =>
        {
            for (int i = 0; i < 100; ++i)
            {
                if (Worker.CancellationPending)
                {
                    break;
                }
                Worker.ReportProgress(i);
                Thread.Sleep(500);
            }
        };

        public string Description(int progress)
        {
            return progress.ToString();
        }
    }

    public MainWindow()
    {
        InitializeComponent();

        Loaded += (object sender, RoutedEventArgs e) => {
            new BackgroundItem(new MyTask());
            new BackgroundItem(new MyTask());
            new BackgroundItem(new MyTask());
        };
    }

    protected override void OnClosed(System.EventArgs e)
    {
        base.OnClosed(e);
        BackgroundDialog.Release(e);
    }
}

Answer 1

尝试查看Application.ShutdownMode 。 您需要将ShutdownMode设置为OnMainWindowClose。

Answer 2

我觉得很傻，一定是星期五结束了。

在BackgroundDialog ：

private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
    e.Cancel = true;
}

在找到此解决方案之前，一定是遗物。 但是，需要进行一些取消才能防止用户从任务栏关闭对话框。 所以我用if (!_Release)语句包装了cancel