使用多个线程显示加载消息的WPF

我以前也发布过类似的问题，但现在我正在根据我决定采用的特定方法来调整这个问题。

简单地说，我想做的是在用户点击一个页面后显示一条加载消息，当下一个页面完全加载（将27000家公司加载到DataGrid中），然后显示下一个网页时，该消息就会消失。订单是这样的；

1. 用户点击第一页上的按钮
2. "Please Wait…"（请稍候…）显示在同一页上，而下一页显示正在加载
3. 下一页已完全加载
4. 隐藏"请稍候……"
5. 显示下一页

建议我使用async和wait。然而，这冻结了我的UI，无法工作（Additional information: The calling thread cannot access this object because a different thread owns it.）。然后我开始考虑使用多个线程，这有望解决我的问题。这就是我迄今为止所尝试的；

用户已单击按钮进入下一页

public CompanyManagement()
    {
        InitializeComponent();
        Thread thread = Thread.CurrentThread;
        this.DataContext = new
        {
            ThreadId = thread.ManagedThreadId
        };
    }

调用页面的Loaded事件

    private void PageLoaded(object sender, RoutedEventArgs e)
    {          
        Thread thread = new Thread(() =>
        {
            var wait = new PleaseWait("My title", "My Message", () => FillDataGrid());
            wait.ShowDialog();
            System.Windows.Threading.Dispatcher.Run();
        });
        thread.SetApartmentState(ApartmentState.STA);
        thread.Start();
    }

FillDataGrid（）是一个花费所有时间（通过OleDB检索公司）的方法，看起来是这样的

private void FillDataGrid()
    {
        var _cDS = new CompanyDataService();
        var Companies = new ObservableCollection<CompanyModel>();
        Companies = _cDS.HandleCompanySelect();
        CompanyICollectionView = CollectionViewSource.GetDefaultView(Companies);
        //CompanyICollectionView.SortDescriptions.Add(new SortDescription("CompanyName", ListSortDirection.Ascending));
        DataContext = this;
        cancelButton.Visibility = Visibility.Hidden;
        if (compNameRad.IsChecked == false && 
            compTownRad.IsChecked == false && 
            compPcodeRad.IsChecked == false)
        {
            searchBox.IsEnabled = false;
        }
        dataGrid.SelectedIndex = 0;
        SetDefaultFilter();
    }

这几乎是因为加载了下一个页面，显示了"Please Wait…."，但我随后得到了错误：调用线程无法访问此对象，因为另一个线程拥有它。我是否错误地使用了线程功能？

编辑：我也应该显示PleaseWait！

    public partial class PleaseWait : Window
    {
        readonly Action _action;
        public PleaseWait(string title, string message, Action action)
        {
            _action = action;
            InitializeComponent();
            this.Title = title;
            this.label.Content = message;
        }
        private async void loaded(object sender, RoutedEventArgs e)
        {
            await Task.Run(() => _action());
            this.Close();
        }
    }

编辑：用于StepUp；

    private void PageLoaded(object sender, RoutedEventArgs e)
    {
        Application.Current.Dispatcher.Invoke(DispatcherPriority.Background, new Action(() =>
        {
            var wait = new PleaseWait("My title", "My Message", () => FillDataGrid());
            wait.ShowDialog();
            Dispatcher.Run();
        }));
    }

    private void FillDataGrid()
    {
        var _cDS = new CompanyDataService();
        var Companies = new ObservableCollection<CompanyModel>();
        Companies = _cDS.HandleCompanySelect();
        CompanyICollectionView = CollectionViewSource.GetDefaultView(Companies);
        //CompanyICollectionView.SortDescriptions.Add(new SortDescription("CompanyName", ListSortDirection.Ascending));
        DataContext = this;
        Application.Current.Dispatcher.Invoke(DispatcherPriority.Background, new Action(() =>
        {
            cancelButton.Visibility = Visibility.Hidden;
            if (compNameRad.IsChecked == false &&  compTownRad.IsChecked == false &&
                compPcodeRad.IsChecked == false)
            {
                searchBox.IsEnabled = false;
            }
            dataGrid.SelectedIndex = 0;
        }));
        SetDefaultFilter();
    }

private void PageLoaded(object sender, RoutedEventArgs e)
{
    Application.Current.Dispatcher.Invoke(DispatcherPriority.Background, new Action(() =>
    {
        var wait = new PleaseWait("My title", "My Message", () => FillDataGrid());
        wait.ShowDialog();
        Dispatcher.Run();
    }));
}