WPF ListView不会更新绑定的字典

public class ObservableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public new TValue this[TKey key]
    {
        get { return base[key]; }
        set
        {
            base[key] = value;
            OnPropertyChanged(nameof(this[key]));
        }
    }
}

public class MyViewModel : INotifyPropertyChanged
{
    private ObservableDictionary<string, string> myDictionary;

    public ObservableDictionary<string, string> MyDictionary
    {
        get { return myDictionary; }
        set
        {
            myDictionary = value;
            OnPropertyChanged(nameof(MyDictionary));
        }
    }

    // 其他代码...

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

<ListView ItemsSource="{Binding MyDictionary}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Key" DisplayMemberBinding="{Binding Key}" />
            <GridViewColumn Header="Value" DisplayMemberBinding="{Binding Value}" />
        </GridView>
    </ListView.View>
</ListView>