Wpf 为什么不刷新ICollectionView？

我不明白为什么我的ICollectionView没有刷新。谁能解释我做错了什么

我制作了一个viewmodel，如下所示：

class ViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Entity> m_entities = new ObservableCollection<Entity>();
    public ICollectionView EntitiesView { get; private set; }
    public ICollectionView HighCountView { get; private set; }

    public ViewModel()
    {
        m_entities.Add(new Entity() { Id = 1, Name = "Erik", Description = "The first" });
        m_entities.Add(new Entity() { Id = 2, Name = "Olle", Description = "The second" });
        m_entities.Add(new Entity() { Id = 3, Name = "Kim", Description = "The last" });


        EntitiesView = CollectionViewSource.GetDefaultView(m_entities);
        EntitiesView.CurrentChanged += new EventHandler(EntitiesView_CurrentChanged);

        HighCountView = new CollectionView(m_entities);
        using (HighCountView.DeferRefresh())
        {
            HighCountView.Filter = e => ((Entity)e).Count > 3;
        }

    }

    private void EntitiesView_CurrentChanged(object sender, EventArgs e)
    {
        Entity current = EntitiesView.CurrentItem as Entity;
        if(current!=null)
        {
            current.Count++;
            HighCountView.Refresh();            // Do I need this line?
            OnPropertyChanged("HighCountView"); // or this?
        }
    }

public partial class MainWindow : Window
{
    private ViewModel vm = new ViewModel();
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        this.DataContext = vm;
    }
}

    <ListBox Grid.Column="0" x:Name="listView1" DisplayMemberPath="Name" ItemsSource="{Binding EntitiesView}" IsSynchronizedWithCurrentItem="True" />
    <ListView Grid.Column="1" x:Name="listView2" DisplayMemberPath="Name" ItemsSource="{Binding HighCountView}" IsSynchronizedWithCurrentItem="True" />

…我在XAML代码中进行绑定，如下所示：

class ViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Entity> m_entities = new ObservableCollection<Entity>();
    public ICollectionView EntitiesView { get; private set; }
    public ICollectionView HighCountView { get; private set; }

    public ViewModel()
    {
        m_entities.Add(new Entity() { Id = 1, Name = "Erik", Description = "The first" });
        m_entities.Add(new Entity() { Id = 2, Name = "Olle", Description = "The second" });
        m_entities.Add(new Entity() { Id = 3, Name = "Kim", Description = "The last" });


        EntitiesView = CollectionViewSource.GetDefaultView(m_entities);
        EntitiesView.CurrentChanged += new EventHandler(EntitiesView_CurrentChanged);

        HighCountView = new CollectionView(m_entities);
        using (HighCountView.DeferRefresh())
        {
            HighCountView.Filter = e => ((Entity)e).Count > 3;
        }

    }

    private void EntitiesView_CurrentChanged(object sender, EventArgs e)
    {
        Entity current = EntitiesView.CurrentItem as Entity;
        if(current!=null)
        {
            current.Count++;
            HighCountView.Refresh();            // Do I need this line?
            OnPropertyChanged("HighCountView"); // or this?
        }
    }

public partial class MainWindow : Window
{
    private ViewModel vm = new ViewModel();
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        this.DataContext = vm;
    }
}

    <ListBox Grid.Column="0" x:Name="listView1" DisplayMemberPath="Name" ItemsSource="{Binding EntitiesView}" IsSynchronizedWithCurrentItem="True" />
    <ListView Grid.Column="1" x:Name="listView2" DisplayMemberPath="Name" ItemsSource="{Binding HighCountView}" IsSynchronizedWithCurrentItem="True" />

---

最后我发现了问题所在

如果我更改行：

    HighCountView = new CollectionView(m_entities);

对此

    HighCountView = new ListCollectionView(m_entities);

然后，它会以预期的方式工作

我也可以删除这一行

        OnPropertyChanged("HighCountView"); // or this?

---

我希望这能帮助别人

请添加实体类的代码。现在是添加的实体类。您可以尝试以下操作：var savedhighcount=HighCountView；HighCountView=null；OnPropertyChanged（“HighCountView”）；HighCountView=savedhighcount；OnPropertyChanged（“HighCountView”）。。。。。仅在底部的构造函数中执行此操作…而不是在CurrentChanged中。没有任何区别…：（我不知道这是否是问题所在，但一般来说，您不直接实例化CollectionView。相反，您应该创建CollectionViewSource的新实例并获取相应的视图。让引擎决定使用HighCountView=new CollectionViewSource{Source=m_entities}的最佳实现是什么。视图；它有帮助！）