.net - 如何在PresentationFramework中调试NullReferenceException？-6ren

.net - 如何在PresentationFramework中调试NullReferenceException？

转载作者：行者123 更新时间：2023-12-02 17:39:02

我的 .NET 4 应用程序使用 WPF TreeView，我已对其进行了增强，以启用键盘导航和延迟加载等功能。我的问题是，很少会抛出下面所示的异常。在几个月的开发过程中，这种情况只发生在我身上一次，而且我收到了一些客户的错误报告，他们也偶尔收到这种情况。这种情况非常罕见，以至于我无法更改某些内容，使用该应用程序一段时间并知道问题是否消失。

但我的主要问题是:堆栈跟踪仅显示 Microsoft 代码，其中没有我的任何内容。这是 .NET/WPF 中的错误吗？有没有机会找到根本原因？

Type: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: PresentationFramework
Stack trace:    at System.Windows.Controls.ItemContainerGenerator.ContainerFromIndex(Int32 index)
  at System.Windows.Controls.TreeViewItem.FindNextFocusableItem(Boolean walkIntoSubtree)
  at System.Windows.Controls.TreeViewItem.InternalPredictFocus(FocusNavigationDirection direction)
  at System.Windows.Controls.VirtualizingStackPanel.FocusChanged(KeyboardFocusChangedEventArgs e)
  at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
  at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
  at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
  at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
  at System.Windows.Input.InputManager.ProcessStagingArea()
  at System.Windows.Input.KeyboardDevice.ChangeFocus(DependencyObject focus, Int32 timestamp)
  at System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
  at System.Windows.Input.KeyboardDevice.Focus(IInputElement element)
  at System.Windows.UIElement.Focus()
  at System.Windows.Controls.TreeViewItem.OnItemsChanged(NotifyCollectionChangedEventArgs e)
  at System.Windows.Controls.ItemsControl.OnItemCollectionChanged(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.SetCollectionView(CollectionView view)
  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.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
  at System.Windows.Data.BindingExpression.Activate(Object item)
  at System.Windows.Data.BindingExpression.OnDataContextChanged(DependencyObject contextElement)
  at System.Windows.Data.BindingExpression.HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
  at System.Windows.Data.BindingExpressionBase.OnPropertyInvalidation(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, Boolean coerceWithCurrentValue, OperationType operationType)
  at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
  at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
  at System.Windows.Controls.ItemContainerGenerator.System.Windows.Controls.Primitives.IItemContainerGenerator.RemoveAll()
  at System.Windows.Controls.VirtualizingStackPanel.ClearAllContainers(ItemsControl itemsControl)
  at System.Windows.Controls.ItemsControl.MS.Internal.Controls.IGeneratorHost.ClearContainerForItem(DependencyObject container, Object item)
  at System.Windows.Controls.ItemContainerGenerator.UnlinkContainerFromItem(DependencyObject container, Object item)
  at System.Windows.Controls.ItemContainerGenerator.Remove(GeneratorPosition position, Int32 count, Boolean isRecycling)
  at System.Windows.Controls.VirtualizingStackPanel.CleanupRange(IList children, IItemContainerGenerator generator, Int32 startIndex, Int32 count)
  at System.Windows.Controls.VirtualizingStackPanel.CleanupContainers(Int32 firstViewport, ItemsControl itemsControl)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.TreeViewItem.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.TreeViewItem.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.TreeViewItem.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.TreeViewItem.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.TreeViewItem.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ScrollContentPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.ScrollViewer.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Border.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Control.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
  at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
  at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Border.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.Controls.Control.MeasureOverride(Size constraint)
  at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
  at System.Windows.UIElement.Measure(Size availableSize)
  at System.Windows.ContextLayoutManager.UpdateLayout()
  at System.Windows.Interop.HwndSource.Process_WM_SIZE(UIElement rootUIElement, IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam)
  at System.Windows.Interop.HwndSource.LayoutFilterMessage(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, Int32 numArgs)
  at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
Target: System.Windows.DependencyObject ContainerFromIndex(Int32)
Inner exception message:

注意:我的机器上也有这个，它运行完全修补的 Windows 7 x64。

最佳答案

我个人从未发现过 WPF 中的错误。然而，单步执行 WPF 代码经常使我能够将问题的根源追溯到我自己。

以下是一些有关如何启用调试框架源的 MSDN 文章:

所有版本的链接:https://msdn.microsoft.com/en-us/library/cc667410.aspx

关于.net - 如何在PresentationFramework中调试NullReferenceException？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8979060/

文章推荐： cuda - 使用多个 CUDA GPU

文章推荐： C# Selenium WebDriver 开关/案例

文章推荐： angularjs - npm lite-server 无法识别 css 中的更改

java - 调试 "Step into"类调用导致 "Class not found"异常 - Eclipse 调试
昨晚我因为这个问题脑子崩溃了。在确保没有来 self 的 eclipse 错误检查的明显错误之后，我开始调试我的程序。顺便说一下，我正在使用 Jre7。无论如何，每次我进入我的类调用(我们称之为“a”
gcc - 是否可以使用 lldb 调试 gcc 编译的程序，或使用 gdb 调试 clang 编译的程序？
(前言:我对 C/C++ 还很陌生，我真的不知道 native 代码中的调试实际上是如何工作的。) 一些消息来源说 gdb 和 lldb 可以调试 any program compiled to ma
debugging - 调试 T4Scaffolding.Core Nuget 包时的 Set-DefaultScaffolder : Cannot get an instance of EnvDTE. DTE - 高级 Powershell 调试
我正在尝试从 Visual Studio 2012 外部调试 T4Scaffolding.Core Nuget 包。我使用的是安装了 Powershell 3.0 的 Powershell ISE，并
调试 assembly
如何调试汇编代码？我在 Linux 上使用 gdb。我知道我可以看寄存器。有哪些调试汇编代码的方法？最佳答案您当然可以使用 breakpoints就像 C 或任何其他编译语言一样。 This ar
Haskell 调试
如何在每次通话时打印列表或 haskell 中的内容，例如: funct a list = funct (a + 1) (a : list) print list her
调试 Makefile
让我用我对 Makefiles 或 make 知之甚少的评论作为这个问题的前缀。有一个非常大的项目，每晚自动构建。它以 Debug 和 Release 模式构建，Debug 用于 Valgrind
计算周薪和加类费的C程序不起作用？调试
我正在创建一个计算每周工资的程序，那么任何加类工资都是该周正常工资的 1.5 倍。我的代码如下: #include int main() { double payrate; double h
JavaScript 调试
我使用的是 Visual Studio 2010 Express Developer 版本。开发网站。我在我的 .aspx 页面中使用 JavaScript。如何在 Javascript 中放置断点
Javascript 调试
我最近开始修补 Project Euler 问题，并尝试用 Javascript 解决它们。这样做我往往会产生许多无限循环，现在我想知道是否有比终止 Firefox 或 Chrome 中的选项卡更好的
Python实时编码/调试
有没有办法在程序执行期间生成一个交互式 python 控制台(最好是 iPython)而不暂停主程序并且能够检查和修改程序变量？类似于浏览器为 JavaScript 提供的功能。我知道 pdb.se
android - 调试 FFmpeg
我正在使用 FFmpeg @ Android 并希望能够进入 FFmpeg 代码(Eclipse + Seqouya)，同时编译 FFmpeg 我使用 --disable-stripping --en
.net - 调试.net进程时如何找到LastError的值？
我从使用互操作调用 win32 api 函数的 .net 进程中得到一个异常。我有一个调试器，我想查看 LastError 的值。是否可以从 Visual Studio 调试器中查看 LastEr
vba - Navigate2 调试
我正在尝试通过 VBA 创建一个宏，以在 IE 的多个选项卡中打开一组指定的链接。目前我正在使用下面的代码，如果我试图打开 3 个或更少的选项卡，它大部分时间都可以工作。任何超过 3 的代码都会在“N
debugging - MonoDevelop 调试？
好的，这似乎是一个愚蠢的问题，因为 MonoDevelop 越来越成熟，所以我确定我只是想念它，但我环顾四周，所有关于这个主题的问题似乎都是关于远程调试或 Mac 上的调试。我使用的是 Ubuntu
调试 littler/Rscripts
如何调试 Rscripts是从命令行运行的？我目前正在使用 getopt传递命令行选项的包，当有错误时，我很难: 看看到底出了什么问题；在 R 中交互式调试(因为脚本需要命令行选项。) 有没有人有
Adobe ExtendScript 调试
支持 PDF 和网络上的信息很少。我碰巧在博客中看到一篇文章，提到 $.write() 或 $.writeln() 将向 javascript 控制台写入一个字符串。相当有用。有谁知道这个 $ 对象是
PyCharm JavaScript 调试
PyCharm 1.5 中是否可以使用 Firefox 和 Chrome 支持的 JavaScript 调试？如果是这样，它能否与 Python/Django 调试器一起有效运行？如果没有，有没有
debugging - 调试 Release模式应用程序的最佳方法
我确定这以前发生在人们身上，某些东西在 Debug模式下工作，你在发布时编译，但有些东西坏了。这发生在我在嵌入式 XP 环境中工作时，我发现最好的方法确实是编写一个日志文件来确定它会出错的地方。您
php - Flow3 调试
我目前正在为即将到来的项目评估 Flow3。 AOP 模式和依赖注入(inject)将非常适合我们的目的。现在我想不通的是如何在 Controller Action 中调试一些结果。 public
Django Gunicorn 调试
最初，我有一个包含测试服务器的 Django 应用程序。要调试此设置，我只需添加 import pdb; pdb.set_trace()代码中的任何位置，并且有一个断点将我扔到终端中的交互式调试器中(

行者123

个人简介

我是一名优秀的程序员,十分优秀！

作者热门文章

滴滴打车优惠券免费领取

全站热门文章

首页

博学

6Ren·AI

商城

.net - 如何在PresentationFramework中调试NullReferenceException？