什么不能在此时修改此节点的逻辑子节点，因为树步行正在进行中？
我在后台工作线程的已完成方法中设置对象的DataContext。 出于某种原因，我收到一个错误说：
此时无法修改此节点的逻辑子节点，因为正在进行树步行指向Chart1.DataContext = allDates行。
树木行走的意义何在？ 我已经尝试使用Dispatcher操作执行此设置，并且出现相同的错误…任何想法？ 谷歌在此错误消息上没有任何结果。
代码导致这是微软Charting工具包的内部……我想知道我是否在他们的控制中发现了一个错误…
没有Dispatcher：
void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { ArticlesPerTimePeriodResult result = (ArticlesPerTimePeriodResult)e.Result; lvArticles.ItemsSource = result.DatesOfArticles; Chart1.DataContext = result.AllDates; } 使用Dispatcher：
void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { ArticlesPerTimePeriodResult result = (ArticlesPerTimePeriodResult)e.Result; lvArticles.ItemsSource = result.DatesOfArticles; Dispatcher.BeginInvoke((Action<List<KeyValuePair>>)(delegate(List<KeyValuePair> allDates) { Chart1.DataContext = allDates; }), result.AllDates); //Chart1.DataContext = result.AllDates; }
错误：
System.Reflection.TargetInvocationException was unhandled Message="Exception has been thrown by the target of an invocation." Source="mscorlib" StackTrace: at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.TranslateAndDispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Application.RunInternal(Window window) at NewsCluesWpf.App.Main() in C:\SoftwareInstall\VSProjects\NewsClues\NewsCluesWpf\obj\Debug\App.g.cs:line 0 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone() at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.InvalidOperationException Message="Cannot modify the logical children for this node at this time because a tree walk is in progress." Source="PresentationFramework" StackTrace: at System.Windows.FrameworkElement.AddLogicalChild(Object child) at System.Windows.Controls.UIElementCollection.InsertInternal(Int32 index, UIElement element) at System.Windows.Controls.DataVisualization.ObservableCollectionListAdapter`1.c__DisplayClass1.b__0(T item, Int32 index) at System.Windows.Controls.DataVisualization.EnumerableFunctions.ForEachWithIndex[T](IEnumerable`1 that, Action`2 action) at System.Windows.Controls.DataVisualization.ObservableCollectionListAdapter`1.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index) at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item) at System.Windows.Controls.DataVisualization.ReadOnlyObservableCollection`1.InsertItem(Int32 index, T item) at System.Collections.ObjectModel.Collection`1.Insert(Int32 index, T item) at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.c__DisplayClass14.c__DisplayClass16.b__f(ReadOnlyObservableCollection`1 that) at System.Windows.Controls.DataVisualization.ReadOnlyObservableCollection`1.Mutate(Action`1 action) at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.c__DisplayClass14.b__e(T item, Int32 index) at System.Windows.Controls.DataVisualization.EnumerableFunctions.ForEachWithIndex[T](IEnumerable`1 that, Action`2 action) at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.ChildCollectionCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index) at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item) at System.Collections.ObjectModel.Collection`1.Add(T item) at System.Windows.Controls.DataVisualization.Charting.Chart.AddAxisToChartArea(Axis axis) at System.Windows.Controls.DataVisualization.Charting.Chart.ActualAxesCollectionChanged(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.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index) at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item) at System.Windows.Controls.DataVisualization.UniqueObservableCollection`1.InsertItem(Int32 index, T item) at System.Collections.ObjectModel.Collection`1.Add(T item) at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.GetAxes(DataPoint firstDataPoint, Func`2 independentAxisPredicate, Func`1 independentAxisFactory, Func`2 dependentAxisPredicate, Func`1 dependentAxisFactory) at System.Windows.Controls.DataVisualization.Charting.AreaSeries.GetAxes(DataPoint firstDataPoint) at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.GetAxes() at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints) at System.Windows.Controls.DataVisualization.Charting.DataPointSingleSeriesWithAxes.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints) at System.Windows.Controls.DataVisualization.Charting.LineAreaBaseSeries`1.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints) at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.LoadDataPoints(IEnumerable newItems, IEnumerable oldItems) at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.Refresh() at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.OnItemsSourceChanged(IEnumerable oldValue, IEnumerable newValue) at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.OnItemsSourceChanged(DependencyObject o, 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, OperationType operationType) at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp) at System.Windows.Data.BindingExpression.Invalidate(Boolean isASubPropertyChange) at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange) at System.Windows.Data.BindingExpression.Activate(Object item) at System.Windows.Data.BindingExpression.HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args) at System.Windows.Data.BindingExpression.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args) at System.Windows.DependentList.InvalidateDependents(DependencyObject source, DependencyPropertyChangedEventArgs sourceArgs) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, OperationType operationType) at System.Windows.TreeWalkHelper.OnInheritablePropertyChanged(DependencyObject d, InheritablePropertyChangeInfo info) at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d) at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren) at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren) at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d) at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d) at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren) at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren) at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d) at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d) at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren) at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren) at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d) at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d) at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren) at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren) at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d) 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 System.Windows.TreeWalkHelper.InvalidateOnInheritablePropertyChange(FrameworkElement fe, FrameworkContentElement fce, InheritablePropertyChangeInfo info, Boolean skipStartNode) 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, OperationType operationType) at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, OperationType operationType, Boolean isInternal) at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value) at System.Windows.FrameworkElement.set_DataContext(Object value) at NewsCluesWpf.ArticlesPerDay.b__1(List`1 allDates) in C:\SoftwareInstall\VSProjects\NewsClues\NewsCluesWpf\ArticlesPerDay.xaml.cs:line 72 InnerException:
在玩了更多之后，我认为这是Silverlight图表工具包中的一个错误。
以下代码导致可重现的崩溃。
int runCount = 0; private void bindChart(string searchString) { List> dataEmpty = new List>(); List> dataFilled = new List>(); dataFilled.Add(new KeyValuePair(DateTime.Today, 1)); if (runCount == 0) { Chart1.DataContext= dataEmpty; } else { Chart1.DataContext = dataFilled; } runCount++; }
XAML：
这将在第二次调用bindChart时失败。
解决了！
问题：我想在每次更改某些数据时更新GUI上的图表。
myChart.DataContext = MTFdata;
当我这样做时，我得到错误：此时无法修改此节点的逻辑子节点，因为正在进行树步行
我是如何解决的：
绝对是这样的：
用这个：
使用ItemsSource="{Binding}"和DataContext="{Binding}"
希望这可以帮助！
HEJ，
我刚刚遇到错误，并修复了它。 设置datacontext时也会出现错误。
我发现我在列表中有一个选择改变的订阅，它已经设置了datacontext。 在这个选择中，我改变了另一个具有通知支持的属性，该属性上有一个可视元素绑定。
通过使用调度程序设置属性解决了问题。
因此，请尝试查找有关更改的订阅…
显然，正在进行一些操作，即在使用它时更改集合。 这是一个很大的禁忌。
如果不进一步分析代码，那就是我所能说的。
这是我对它的研究。
当树遍历正在进行时，它是由FrameworkElement和FrameworkContentElement中的Add / RemoveLogicalChild方法抛出的WPFexception。 它的枯燥细节在博客文章中，但最重要的是你不能做更多的测试，然后抓住它发生的地方。 例外情况应该是相对罕见的。
而不是通过可观察集合重置DataContext重用也可以…
int runCount = 0; private void bindChart() { ObservableCollection> data = new ObservableCollection>(); if (runCount == 0) { this.DataContext = dataEmpty; } else { var de = this.DataContext as ObservableCollection>; de.Clear(); for (var i = 0; i < (new Random(DateTime.Now.Second)).Next(100); i++) { de.Add(new KeyValuePair(DateTime.Today.AddDays(i), i)); } } runCount++; }
我刚刚遇到WPF图表工具包的这个问题。 每个人都说不要绑定到DataContext并直接绑定到ItemsSource，但我已经绑定到ItemsSource并仍然得到错误。 在我的例子中，我绑定到ListBox或TreeView的SelectedItem 。 我唯一可以工作的是当SelectedItemChanged（）事件触发时手动绑定到ItemsSource 。
private void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs
当父控件（AvalonDock）触发子用户控件重新加载时，我遇到了这个问题：用户控件将触发其“已加载”事件，我的应用程序将崩溃。
我从用户控件中删除了Loaded事件处理程序，并使用了Initialized事件。 这解决了我的问题，虽然我不完全确定原因。
我也有同样的问题。 我没有使用任何后台线程。 我只有一个滑块和滑块的ValueChanged事件，我正在重新计算并重置DataContext。
例如，A烧毁图表。 随着初始值的变化，图形会自动更新（基本上是线序列的Y轴）。
更改datacontext在Silverlight 3的测试版中工作。在发行版中不起作用。 以上关于设置的注释（Chart1.Series [0]为DataPointSeries）.ItemsSource适合我