Question

所以我有一个可观察的集合绑定到ItemsControl。

当我向集合中添加项目时，我从Visual集合中获得了超出范围的索引的异常。

<ItemsControl x:Name="ReportPages" ItemsSource="{Binding History}" DockPanel.Dock="Top">
    <ItemsControl.Template>
        <ControlTemplate TargetType="ItemsControl">
            <ItemsPresenter HorizontalAlignment="Center"/>
        </ControlTemplate>
    </ItemsControl.Template>
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <StackPanel />
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <ItemsControl ItemsSource="{Binding ChildWindows}">
                <ItemsControl.Template>
                    <ControlTemplate TargetType="ItemsControl">
                        <Grid Margin="0,10,0,10" >
                            <ItemsPresenter />
                            <Border x:Name="ResizeFrame" BorderThickness="4" BorderBrush="LightBlue"  Visibility="{Binding Active, Converter={StaticResource BooleanToVisibilityConverter}}"/>
                        </Grid>
                    </ControlTemplate>
                </ItemsControl.Template>
                <ItemsControl.ItemsPanel>
                    <ItemsPanelTemplate>
                        <Canvas x:Name="LayoutCanvas" Background="white" ClipToBounds="true"
                    MouseDown="History_MouseLeftButtonDown" PreviewMouseDown="ClosePanels"
                    Width="{Binding PageSizeProp.PageWidth}" Height="{Binding PageSizeProp.PageHeight}"/>
                    </ItemsPanelTemplate>
                </ItemsControl.ItemsPanel>
            </ItemsControl>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

内部ChildWindows是我要添加项目的集合。需要注意的是，ChildWindows是一个ReadOnlyObservableCollection，我通过一个可以访问它所基于的Collection的方法添加。

我完全不知道为什么会发生这种情况（而且只有一些时间）。

编辑：这是实际的堆栈跟踪

at System.Windows.Media.VisualCollection.Insert(Int32 index, Visual visual)
   at System.Windows.Controls.Panel.addChildren(GeneratorPosition pos, Int32 itemCount)
   at System.Windows.Controls.Panel.OnItemsChangedInternal(Object sender, ItemsChangedEventArgs args)
   at System.Windows.Controls.Panel.OnItemsChanged(Object sender, ItemsChangedEventArgs args)
   at System.Windows.Controls.ItemContainerGenerator.OnItemAdded(Object item, Int32 index)
   at System.Windows.Controls.ItemContainerGenerator.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at System.Windows.Controls.ItemContainerGenerator.System.Windows.IWeakEventListener.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
   at System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
   at System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
   at System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Windows.Data.CollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at System.Windows.Controls.ItemCollection.System.Windows.IWeakEventListener.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
   at System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
   at System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
   at System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at System.Windows.Data.CollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at System.Windows.Data.ListCollectionView.ProcessCollectionChangedWithAdjustedIndex(NotifyCollectionChangedEventArgs args, Int32 adjustedOldIndex, Int32 adjustedNewIndex)
   at System.Windows.Data.ListCollectionView.ProcessCollectionChanged(NotifyCollectionChangedEventArgs args)
   at System.Windows.Data.CollectionView.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.HandleCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
   at System.Collections.ObjectModel.Collection`1.Add(T item)
   at CalManv4UI.DataHistoryReportPageBase.AddNewChart(ChildWindowSaved cws, Boolean activate) in C:\Users\Joel Barsotti\Documents\Visual Studio 2010\Projects\CalMAN V4\CalMANv4-WPF\CalManv4UI\Workflow\DataHistoryReportPageBase.cs:line 72

Answer 1

我有同样的问题和我对它的理解
（对{链接} https://stackoverflow.com/users/249723/vivien-ruiz的信用）
如果你修改一个参与ItemSource绑定的ObservableCollection，你就会“绑定”出现问题。我发现在索引0处插入“解决”了我的问题，但它仍然可能崩溃。
不应该修改它，因为它不是一个线程安全的类。
更好的解决方案是对列表的副本进行操作，并在操作完成后将副本分配给有界集合。
例如：ObservableCollection<ListViewItem> newList = new ObservableCollection<ListViewItem>(mCurrentList); ... ListViewItem item = new ListViewItem(); item.Content = image; newList.Add(item); ... mPictures = newList;

Answer 2

我有类似的问题，花了我几个月的时间找出原因，但发现它^^ 检查this site，特别是如果您从另一个线程修改列表。你似乎有一个竞争条件，可能这是同一个！

抛出范围异常的VisualCollection，绑定到Observable集合

2 个答案: