Question

此给定页面显示特定州的所有城市。我在ListView中显示ListView。外部ListView显示城市列表。内部ListView显示附加到每个特定城市的所有注释。

一切都正常加载。我可以添加一个注释，它会被添加到数据库中。但是，添加注释后，单击NotesListView中的滚动条会导致异常：

ItemsControl与其商品来源
不一致

我理解这个问题...在我向viewmodel中的city.Notes属性添加注释后，附加到ListView的注释列表变得不同步...但是如何强制这个ListView刷新？

这是我的XAML（为简洁而编辑）：

<ListView x:Name="CityListView" ItemsSource="{Binding CityDetails, Mode=OneWay}">
<!--City Name and other city details. go here-->
   <ListView  x:Name="NotesListView" ItemsSource="{Binding Notes}">
    <TextBlock Text="{Binding Path=Note}" />
</ListView>
<StackPanel>
  <TextBlock Text="Add Note:" />
  <TextBox Text="{Binding Path=DataContext.Note, RelativeSource={RelativeSource AncestorType=UserControl}}" />
  <Button Content="ADD NOTE" Command="{Binding Path=DataContext.AddNoteCommand, RelativeSource={RelativeSource AncestorType=UserControl}}" CommandParameter="{Binding}" />

</StackPanel>
</ListView>

以下是ViewModel中的AddNote（）方法，该方法挂钩到AddNoteCommand：

Protected _stateService As IStateService
Protected _state As State

Protected Sub OnAddNote(city As City)
        Dim note As Note = Nothing

        If Not String.IsNullOrWhiteSpace(Me.Note) Then
            note = New Note() With {
                .Note = Me.Note,
                .NoteDate = DateTime.Now,
            }

            city.Notes.Add(note)

            _stateService.SaveExistingState(_state)
            ' this saves the note, since _state contains:
            ' Property Cities As ICollection(Of City)
            ' and the city object passed into this method belongs to that collection...

            RaisePropertyChanged(Function() city.Notes)
        End If
    End Sub

Answer 1

在C＃中我解决了这个问题：

Dispatcher.CurrentDispatcher.Invoke(
    new Action<Note>(item => city.Notes.Add(item)),
    DispatcherPriority.Background,
    note);

ItemsControl与其项源不一致 - 发生在嵌套的ListView中

1 个答案: