WPF ReactiveUI 绑定 Listbox.ItemsSource 到 ReadOnlyObservableCollection 不起作用

Question

在我的 WPF+ReactiveUI+DynamicData 项目中，我无法将 ListBox.ItemsSource 绑定到 ReadOnlyObservableCollection 工作。我成功地通过后端服务将数据填充到我的 ViewModel

public class RecordingsListViewModel: ReactiveObject
    {
        private readonly ReadOnlyObservableCollection<RecordingViewModel> _recordings;
        public ReadOnlyObservableCollection<RecordingViewModel> Recordings => _recordings;

        public RecordingsListViewModel(IRecordingsService recordindsService)
        {
            recordindsService.RecordingsList.Connect()
                .Transform(rec => new RecordingViewModel(rec as IRecordingModel))
                .Bind(out _recordings)
                .Subscribe();
        }
    }

我的看法：

<reactiveui:ReactiveUserControl x:Class="MyProject.Views.RecordingsListView"
                                x:TypeArguments="vm:RecordingsListViewModel"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:vm="clr-namespace:MyProject.ViewModels"
             xmlns:reactiveui="http://reactiveui.net"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">

    <ListBox x:Name ="RecordingsListBox" HorizontalContentAlignment="Stretch"/>

</reactiveui:ReactiveUserControl>

在我后面的代码中，我尝试绑定但它不起作用

    {
        public static readonly DependencyProperty ViewModelProperty = DependencyProperty
        .Register(nameof(ViewModel), typeof(RecordingsListViewModel), typeof(RecordingsListView));

        public RecordingsListViewModel ViewModel
        {
            get => (RecordingsListViewModel)GetValue(ViewModelProperty);
            set => SetValue(ViewModelProperty, value);
        }

        object IViewFor.ViewModel
        {
            get => ViewModel;
            set => ViewModel = (RecordingsListViewModel)value;
        }

        public RecordingsListView()
        {
            ViewModel = Locator.Current.GetService<RecordingsListViewModel>();
            InitializeComponent();

            this.WhenActivated(d =>
            {
                this.OneWayBind(ViewModel,
                   vm => ViewModel.Recordings,
                   view => view.RecordingsListBox.ItemsSource).DisposeWith(d);
            });
        }
    }

输出有错误，但不会导致应用程序崩溃

PropertyBinderImplementation: view.RecordingsListBox.ItemsSource Binding received an Exception! - System.NotSupportedException: Unsupported expression of type 'Constant'. Did you miss the member access prefix in the expression?
   at ReactiveUI.ExpressionMixins.GetExpressionChain(Expression expression) in /_/src/ReactiveUI/Mixins/ExpressionMixins.cs:line 78
   at ReactiveUI.ReactiveNotifyPropertyChangedMixin.SubscribeToExpressionChain[TSender,TValue](TSender source, Expression expression, Boolean beforeChange, Boolean skipInitial, Boolean suppressWarnings) in /_/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs:line 140
   at ReactiveUI.WhenAnyMixin.WhenAnyDynamic[TSender,TRet](TSender sender, Expression property1, Func`2 selector) in /_/src/ReactiveUI/VariadicTemplates.cs:line 99
   at ReactiveUI.Reflection.<>c__DisplayClass15_0`2.<ViewModelWhenAnyValue>b__2(Object x) in /_/src/ReactiveUI/Expression/Reflection.cs:line 407
   at System.Reactive.Linq.ObservableImpl.Select`2.Selector._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/Select.cs:line 39

我在谷歌上搜索这个错误和相关示例将近 16 个小时，尝试了很多代码调整但没有任何运气。非常感谢任何想法

Answer 1

非常感谢 Glenn Watson 和
Đøharrrck 评论。我终于修好了。问题是在绑定中错误地访问了 viewModel。是：

this.OneWayBind(ViewModel,
                   vm => ViewModel.Recordings,
                   view => view.RecordingsListBox.ItemsSource).DisposeWith(d);

应该是：

this.OneWayBind(ViewModel,
                   vm => vm.Recordings,
                   view => view.RecordingsListBox.ItemsSource).DisposeWith(d);

WPF ReactiveUI 绑定 Listbox.ItemsSource 到 ReadOnlyObservableCollection 不起作用

WPF ReactiveUI binding Listbox.ItemsSource to ReadOnlyObservableCollection not working

c#

wpf

reactiveui

dynamic-data