c# - Creators Update 后在 OnCollectionChanged 上获取线程访问异常

Question

在我的程序中，我有一个抽象类 ObservableKeyedCollection<TKey, TItem>继承自 KeyedCollection<TKey, TItem>并且还实现了 INotifyCollectionChanged .

此抽象类的实现绑定(bind)到 ListBox .在这个ListBox ，我双击编辑项目，并在接受后，从这个 ObservableKeyedCollection<TKey, TItem> 中删除编辑项目的旧实例实现，并添加修改后的新实​​例。

在 Windows 10 Creators Update(1703，内部版本号 15063.250)之前一切正常。自更新以来，ObservableKeyedCollection<TKey, TItem>开始 throw InvalidOperationException带有以下消息:

The calling thread cannot access this object because a different thread owns it.

我没有在代码的这个区域使用任何异步操作。

整个堆栈跟踪会太长，但这里是顶部以 OnCollectionChanged 开头的部分:

at System.Windows.Threading.Dispatcher.VerifyAccess() at System.Windows.Threading.DispatcherObject.VerifyAccess() at System.Windows.DependencyObject.GetValue(DependencyProperty dp) at System.Windows.Controls.Primitives.Selector.GetIsSelected(DependencyObject element) at System.Windows.Controls.Primitives.Selector.ItemSetIsSelected(ItemInfo info, Boolean value) at System.Windows.Controls.Primitives.Selector.SelectionChanger.CreateDeltaSelectionChange(List'1 unselectedItems, List'1 selectedItems) at System.Windows.Controls.Primitives.Selector.SelectionChanger.End() at System.Windows.Controls.Primitives.Selector.RemoveFromSelection(NotifyCollectionChangedEventArgs e) at System.Windows.Controls.Primitives.Selector.OnItemsChanged(NotifyCollectionChangedEventArgs e) at System.Windows.Controls.ItemsControl.OnItemCollectionChanged2(Object sender, NotifyCollectionChangedEventArgs e) at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e) at System.Windows.Data.CollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args) at System.Windows.Controls.ItemCollection.OnViewCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) at System.Windows.WeakEventManager.ListenerList'1.DeliverEvent(Object sender, EventArgs e, Type managerType) 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 TetheredSun.ObservableKeyedCollection'2.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at e:\Phil\Programozás\Modulok\TetheredSun.1.0\TetheredSun\ObservableKeyedCollection.cs, line number: 68 at TetheredSun.ObservableKeyedCollection`2.RemoveItem(Int32 index) at [...]

编辑 1:

这是在创意者更新(重写 KeyedCollection<TKey, TItem>.RemoveItem(int index)
)之前可以正常工作的违规代码部分:

protected override void RemoveItem(int index)
{
    TItem item = this[index];
    base.RemoveItem(index);
    if (deferNotifyCollectionChanged) return;
    if (item is IList) {
        // Listeners do not support multiple item changes, and our item happens to be an IList, so we must raise NotifyCollectionChangedAction.Reset.
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    } else {
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item));
    }
    OnPropertyChanged(new PropertyChangedEventArgs("Count"));
}

问题似乎只有在我调用 OnCollectionChanged 时才会出现与 NotifyCollectionChangedAction.Remove行动。将其替换为 NotifyCollectionChangedAction.Reset似乎避免了异常:

protected override void RemoveItem(int index)
{
    TItem item = this[index];
    base.RemoveItem(index);
    if (deferNotifyCollectionChanged) return;
    // No exception thrown so far if I stick to NotifyCollectionChangedAction.Reset:
    OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    OnPropertyChanged(new PropertyChangedEventArgs("Count"));
}

我尝试用 Dispatcher 解决问题如此处所示:https://stackoverflow.com/a/22026686/2659699但是虽然我的调度员不为空，但它是 CheckAccess()计算结果为真，我在 NotifyCollectionChangedEventHandler.Invoke() 上不断收到相同的异常.

非常感谢您的想法和帮助。

Answer 1

我遇到了类似的问题，并且在 Win 10 创作者更新后也是如此。

这个使用 BindingOperations.EnableCollectionSynchronization 的包装类对我有用:

public class SynchronizedObservableCollection<T> : ObservableCollection<T>
{
    private readonly object _lockObject = new object();

    public SynchronizedObservableCollection()
    {
        Init();
    }

    public SynchronizedObservableCollection(List<T> list) : base(list)
    {
        Init();
    }

    public SynchronizedObservableCollection(IEnumerable<T> collection) : base(collection)
    {
        Init();
    }

    private void Init()
    {
        BindingOperations.EnableCollectionSynchronization(this, _lockObject);
    }
}