c# - CollectionViewSource 使用问题

Question

我正在尝试对 CollectionViewSource 进行基本使用，但我肯定遗漏了一些东西，因为它无法正常工作。这是我的 XAML:

<Window.Resources>
  <CollectionViewSource Source="{Binding loc:MainVM.Instance.MapItems}" x:Key="MapCV">
     <CollectionViewSource.GroupDescriptions>
        <PropertyGroupDescription PropertyName="SourceProject" />
     </CollectionViewSource.GroupDescriptions>
  </CollectionViewSource>
</Window.Resources>

---

<ListBox ItemsSource="{StaticResource MapCV}" HorizontalContentAlignment="Stretch" ScrollViewer.HorizontalScrollBarVisibility="Disabled">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Grid HorizontalAlignment="Stretch">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="2*"/>
                    <ColumnDefinition Width="2*"/>
                    <ColumnDefinition Width="50"/>
                </Grid.ColumnDefinitions>
                <TextBlock Grid.Column="0" Text="{Binding SourceType, Converter={StaticResource WorkItemTypeToStringConverter}}"/>
                <ComboBox Grid.Column="1" SelectedItem="{Binding DestType}" ItemsSource="{Binding WorkItemTypesForCurrentDestProject, Source={x:Static loc:MainMediator.Instance}, diagnostics:PresentationTraceSources.TraceLevel=High}" DisplayMemberPath="Name" />
                <Button Grid.Column="2" Content="{Binding PercentMapped}"/>
            </Grid>
        </DataTemplate>                                        
    </ListBox.ItemTemplate>
</ListBox>

这编译正常，但是当我运行应用程序时我得到这个错误:

Cannot convert the value in attribute 'ItemsSource' to object of type 'System.Collections.IEnumerable'. 'System.Windows.Data.CollectionViewSource' is not a valid value for property 'ItemsSource'.  Error at object 'System.Windows.Controls.ListBox' in markup file 'WIAssistant;component/main.xaml

This is the collection I am attaching to:

// The mappings used to copy the values of the fields of one WorkItem to another.
public ObservableCollection<WorkItemTypeMapping> WorkItemTypeMappings
{
    get { return (ObservableCollection<WorkItemTypeMapping>)
          GetValue(WorkItemTypeMappingsProperty); }
    set { SetValue(WorkItemTypeMappingsProperty, value); }
}
public static readonly DependencyProperty WorkItemTypeMappingsProperty = 
    DependencyProperty.Register("WorkItemTypeMappings", 
    typeof(ObservableCollection<WorkItemTypeMapping>), typeof(MainMediator), 
    new UIPropertyMetadata(null));

我只想对对象 Project SourceProject 进行简单分组。我宁愿不必为此分解 TreeView 。

Answer 1

这应该适合你

<ListBox ItemsSource="{Binding Source={StaticResource MapCV}}" ...