我最近遇到了一个非常糟糕的WPF错误。我认为它与Microsoft Connect上的this bug相同。
我们的应用程序使用Visual Studio 2010定位.NET 4.0 Client Profile。
基本上，当ViewModel触发对任何导致项目在ItemsControl中移动的属性或集合的更改时，可能会抛出下面的异常。它并不总是发生，似乎是基于不同时间的不同触发器发生的。在启动应用程序后不久，它似乎更有可能。如果您可以使用它几分钟而不会遇到异常，那么您可能永远不会在该应用程序实例中点击。
与Connect错误报告一样，我正在使用{DynamicResource key}从SolidColorBrush加载ResourceDictionary es。一些字典是手动加载的（用于支持）。我尝试手动冻结这些词典中的所有内容，但似乎没有帮助。
最近，当我向主窗口添加了几个UserControl时，异常变得更加频繁，其中ItemsControls绑定到ObservableCollection s。以前，我只会看到50次中的1次异常，但现在我看到它有5次使用该程序。
有没有人有任何解决方法的想法？ Connect错误表明这可能会在下一个.NET版本中修复（无论何时），但是这个错误使我们的应用程序现在基本上无法使用。
System.InvalidOperationException: Specified value of type 'System.Windows.Media.SolidColorBrush' must have IsFrozen set to false to modify.
at System.Windows.Freezable.WritePreamble()
at System.Windows.Freezable.remove_Changed(EventHandler value)
at System.Windows.ResourceReferenceExpression.ResourceReferenceExpressionWeakContainer.RemoveChangedHandler()
at System.Windows.ResourceReferenceExpression.ResourceReferenceExpressionWeakContainer.InvalidateTargetSubProperty(Object sender, EventArgs args)
at System.Windows.Freezable.FireChanged()
at System.Windows.Freezable.Freeze(Boolean isChecking)
at System.Windows.Freezable.Freeze()
at System.Windows.Freezable.System.Windows.ISealable.Seal()
at System.Windows.StyleHelper.SealIfSealable(Object value)
at System.Windows.StyleHelper.GetChildValueHelper(UncommonField`1 dataField, ItemStructList`1& valueLookupList, DependencyProperty dp, DependencyObject container, FrameworkObject child, Int32 childIndex, Boolean styleLookup, EffectiveValueEntry& entry, ValueLookupType& sourceType, FrameworkElementFactory templateRoot)
at System.Windows.StyleHelper.GetChildValue(UncommonField`1 dataField, DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, EffectiveValueEntry& entry, ValueLookupType& sourceType, FrameworkElementFactory templateRoot)
at System.Windows.StyleHelper.GetValueFromTemplatedParent(DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, FrameworkElementFactory templateRoot, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.GetValueFromTemplatedParent(DependencyProperty dp, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.GetRawValue(DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.EvaluateBaseValueCore(DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry& newEntry)
at System.Windows.DependencyObject.EvaluateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry newEntry, OperationType operationType)
at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp)
at System.Windows.StyleHelper.InvalidateResourceDependentsForChild(DependencyObject container, DependencyObject child, Int32 childIndex, ResourcesChangeInfo info, FrameworkTemplate parentTemplate)
at System.Windows.TreeWalkHelper.InvalidateStyleAndReferences(DependencyObject d, ResourcesChangeInfo info, Boolean containsTypeOfKey)
at System.Windows.TreeWalkHelper.OnResourcesChanged(DependencyObject d, ResourcesChangeInfo info, Boolean raiseResourceChangedEvent)
at System.Windows.FrameworkElement.OnAncestorChangedInternal(TreeChangeInfo parentTreeState)
at System.Windows.TreeWalkHelper.OnAncestorChanged(DependencyObject d, TreeChangeInfo info)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
at MS.Internal.PrePostDescendentsWalker`1._VisitNode(DependencyObject d)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1.StartWalk(DependencyObject startNode, Boolean skipStartNode)
at MS.Internal.PrePostDescendentsWalker`1.StartWalk(DependencyObject startNode, Boolean skipStartNode)
at System.Windows.TreeWalkHelper.InvalidateOnTreeChange(FrameworkElement fe, FrameworkContentElement fce, DependencyObject parent, Boolean isAddOperation)
at System.Windows.FrameworkElement.OnVisualParentChanged(DependencyObject oldParent)
at System.Windows.Media.Visual.FireOnVisualParentChanged(DependencyObject oldParent)
at System.Windows.Media.Visual.RemoveVisualChild(Visual child)
at System.Windows.Media.VisualCollection.DisconnectChild(Int32 index)
at System.Windows.Media.VisualCollection.Clear()
at System.Windows.Controls.UIElementCollection.ClearInternal()
at System.Windows.Controls.Panel.ClearChildren()
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.OnRefresh()
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.RefreshOverride()
at System.Windows.Data.CollectionView.Refresh()
at System.Windows.Data.CollectionView.EndDefer()
at System.Windows.Data.CollectionView.DeferHelper.Dispose()
at System.Windows.Controls.ItemCollection.SetCollectionView(CollectionView view)
at System.Windows.Controls.ItemCollection.SetItemsSource(IEnumerable value)
at System.Windows.Controls.ItemsControl.OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp)
at System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
at System.Windows.Data.BindingExpression.ScheduleTransfer(Boolean isASubPropertyChange)
at MS.Internal.Data.ClrBindingWorker.NewValueAvailable(Boolean dependencySourcesChanged, Boolean initialValue, Boolean isASubPropertyChange)
at MS.Internal.Data.PropertyPathWorker.UpdateSourceValueState(Int32 k, ICollectionView collectionView, Object newValue, Boolean isASubPropertyChange)
at MS.Internal.Data.ClrBindingWorker.OnSourcePropertyChanged(Object o, String propName)
at MS.Internal.Data.PropertyPathWorker.System.Windows.IWeakEventListener.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
at System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
at System.ComponentModel.PropertyChangedEventManager.OnPropertyChanged(Object sender, PropertyChangedEventArgs args)
at ***.ViewModelBase.OnPropertyChanged(String name) in c:\***\ViewModelBase.cs:line 17
.....
编辑：
我们还试图简单地抑制在ViewModel基类的PropertyChanged事件中抛出的任何InvalidOperationException。这似乎有点减少了例外的数量，但现在我们只是在ObservableCollection的{{1}}事件中点击它们。
答案 0 :(得分：20)
要解决此.net错误，请将代码中的所有纯色画笔更改为可冻结。例如
<SolidColorBrush x:Key="WindowBackground" Color="Black" />
应更改为：
<SolidColorBrush po:Freeze="True" x:Key="WindowBackground" Color="Black" />.
有关详细说明，请参阅此处：How can WPF objects deriving from Freezable be frozen in XAML?。
答案 1 :(得分：3)
我不相信这有解决办法。在我必须自己处理这个问题时，从我读过的内容来看，WPF会在创建时自动冻结资源。因此，只要您尝试在该资源上使用DynamicResource，您就会获得freezable异常。
以下是Microsoft基金会团队对正在发生的事情的引用：
“WPF将冻结样式或模板中的任何freezables。样式和 模板可用于多个线程，freezables不能用于 他们被冻结了。我们目前正在考虑将此扩展到任何内容 在Application.Resources中，因为它有相同的线程问题...... 冻结的freezable上的DynamicResource不起作用，因为a 冻结的freezable可能有多个父母 - 所以它是模棱两可的 我们会搜索资源。“
答案 2 :(得分：0)
每次涉及使用ItemsControl和派生控件的MVVM的错误行为时，我的第一次尝试是禁用VirtualizingStackPanel。
<ItemsControl VirtualizingStackPanel.IsVirtualizing="False" />
试一试......