使用异步/等待，但UI仍然使用Caliburn.Micro BindableCollection AddRange挂起

Question

I have facing a problem where my UI is unresponsive for a one sec or so and I guess its my Async/Await skills that are not upgraded to latest version.

Its a WPF app using the Caliburn Micro Framework. What I have found sofar is that my UI is responsive while it is seaching packages (Nuget.Core) and its when the Task have returned with a list of elements and its doign AddRange on the bindable collection. (Its on a feed with max 5 elements, so I dont see why it should take more then a few ms to put that few elements into the collection.

    protected override async void OnActivate()
    {
        base.OnActivate();
        this.PropertyChanged += PluginManagerViewModel_PropertyChanged;            

        IsBusy = true;
        var list = await SearchPackages();
        this.Packages.AddRange(list);
        IsBusy = false;

    }
    async void  PluginManagerViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        switch (e.PropertyName)
        {
            case "SelectedVersion":
            case "SelectedSortBy":
               var list= await SearchPackages();
               this.Packages.AddRange(list);
                break;
            default:
                break;
        }

    }
    public BindableCollection<IPackage> Packages { get; set; }
    private Task<IEnumerable<IPackage>> SearchPackages()
    {
        return Task.Run(() =>
                SelectedSortBy.OrderBy(
                (_manager.SourceRepository
                .Search("", SelectedVersion != "Stable")))
                .AsEnumerable()
                .Where(PackageExtensions.IsListed));
    }

Here is the listview:

<ListView ScrollViewer.PanningMode="VerticalFirst"
                   ScrollViewer.VerticalScrollBarVisibility="Visible"
                   ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                   ScrollViewer.PanningRatio="0.5"
                   x:Name="Packages">
                   <ListView.ItemTemplate>
                    <DataTemplate>
                            <Grid cal:Bind.Model="{Binding}">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition/>
                                <ColumnDefinition Width="4*"/>
                            </Grid.ColumnDefinitions>
                            <TextBlock x:Name="Description" Grid.Column="1" Margin="10,27.96,136,0" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Height="62.04"/>
                            <TextBlock x:Name="Title" TextWrapping="Wrap"  VerticalAlignment="Top"  FontWeight="Bold" Grid.Column="1" Margin="10,10,136,0"/>
                            <Button Content="Install" HorizontalAlignment="Right" VerticalAlignment="Top" Width="121" Grid.Column="1" Margin="0,10,10,0"/>
                            <TextBlock Grid.Column="1" x:Name="Version" HorizontalAlignment="Right"  Margin="0,32.96,10,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120" TextAlignment="Right" FontWeight="Bold"/>
                        </Grid>
                    </DataTemplate>
                   </ListView.ItemTemplate>
            </ListView>

Answer 1

Not a perfect solution but atleast my UI is responsive again.

    private async Task UpdatePackagesCollection()
    {

        IsBusy = true;
        var list = await SearchPackages().ConfigureAwait(false);    
        this.Packages.Clear();
        IsBusy = false;
        foreach (var p in list)
        {
            await App.Current.Dispatcher.InvokeAsync(() =>
            {
                Packages.Add(p);

            }, DispatcherPriority.ContextIdle);
        }  
    }