NullReferenceException: 未将对象引用设置到对象的实例。
StackTrace:
   在 System.Windows.Controls.Primitives.Popup.OnWindowResize(Object sender, AutoResizedEventArgs e)
   在 System.Windows.Interop.HwndSource.Resize(Size newSize)
   在 System.Windows.Interop.HwndSource.OnLayoutUpdated(Object obj, EventArgs args)
   在 System.Windows.ContextLayoutManager.fireLayoutUpdateEvent()
   在 System.Windows.ContextLayoutManager.UpdateLayout()
   在 System.Windows.Controls.ItemsControl.MakeVisible(FrameworkElement container, FocusNavigationDirection direction, Boolean alwaysAtTopOfViewport)
   在 System.Windows.Controls.ItemsControl.MakeVisible(Int32 index, FocusNavigationDirection direction, Boolean alwaysAtTopOfViewport, FrameworkElement& container)
   在 System.Windows.Controls.ItemsControl.NavigateToItem(Object item, Int32 elementIndex, ItemNavigateArgs itemNavigateArgs, Boolean alwaysAtTopOfViewport)
   在 System.Windows.Controls.ItemsControl.NavigateToItem(ItemInfo info, ItemNavigateArgs itemNavigateArgs, Boolean alwaysAtTopOfViewport)
   在 System.Windows.Controls.ComboBox.<>c.<OnIsDropDownOpenChanged>b__20_1(Object arg)
   在 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   在 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

XamlParseException: XAML 节点流: StartMember“System.Windows.Controls.ContentControl.Content”前面缺少 StartObject。
--LineNumber: 0
--LinePosition: 0
--BaseUri: pack://application:,,,/Quicker;component/app.xaml
StackTrace:
   在 System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
   在 System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   在 System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
   在 System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
   在 System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
   在 System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
   在 System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
   在 System.Windows.DeferredResourceReference.GetValue(BaseValueSourceInternal valueSource)
   在 System.Windows.DeferredAppResourceReference.GetValue(BaseValueSourceInternal valueSource)
   在 System.Windows.DependencyObject.GetEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, RequestFlags requests)
   在 System.Windows.DependencyObject.GetValueEntry(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, RequestFlags requests)
   在 System.Windows.DependencyObject.GetValue(DependencyProperty dp)
   在 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)
   在 System.Windows.StyleHelper.GetChildValue(UncommonField`1 dataField, DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, EffectiveValueEntry& entry, ValueLookupType& sourceType, FrameworkElementFactory templateRoot)
   在 System.Windows.StyleHelper.GetValueFromTemplatedParent(DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, FrameworkElementFactory templateRoot, EffectiveValueEntry& entry)
   在 System.Windows.StyleHelper.ApplyTemplatedParentValue(DependencyObject container, FrameworkObject child, Int32 childIndex, FrugalStructList`1& childRecordFromChildIndex, DependencyProperty dp, FrameworkElementFactory templateRoot)
   在 System.Windows.StyleHelper.InvalidatePropertiesOnTemplateNode(DependencyObject container, FrameworkObject child, Int32 childIndex, FrugalStructList`1& childRecordFromChildIndex, Boolean isDetach, FrameworkElementFactory templateRoot)
   在 System.Windows.FrameworkTemplate.InvalidatePropertiesOnTemplate(DependencyObject container, Object currentObject)
   在 System.Windows.FrameworkTemplate.HandleBeforeProperties(Object createdObject, DependencyObject& rootObject, DependencyObject container, FrameworkElement feContainer, INameScope nameScope)
   在 System.Windows.FrameworkTemplate.<>c__DisplayClass45_0.<LoadOptimizedTemplateContent>b__2(Object sender, XamlObjectEventArgs args)
   在 System.Xaml.XamlObjectWriter.OnBeforeProperties(Object value)
   在 System.Xaml.XamlObjectWriter.Logic_CreateAndAssignToParentStart(ObjectWriterContext ctx)
   在 System.Xaml.XamlObjectWriter.WriteStartMember(XamlMember property)
   在 System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlReader templateReader, XamlObjectWriter currentWriter)
   在 System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlObjectWriter objectWriter)
   在 System.Windows.FrameworkTemplate.LoadOptimizedTemplateContent(DependencyObject container, IComponentConnector componentConnector, IStyleConnector styleConnector, List`1 affectedChildren, UncommonField`1 templatedNonFeChildrenField)
   在 System.Windows.FrameworkTemplate.LoadContent(DependencyObject container, List`1 affectedChildren)
   在 System.Windows.StyleHelper.ApplyTemplateContent(UncommonField`1 dataField, DependencyObject container, FrameworkElementFactory templateRoot, Int32 lastChildIndex, HybridDictionary childIndexFromChildID, FrameworkTemplate frameworkTemplate)
   在 System.Windows.FrameworkTemplate.ApplyTemplateContent(UncommonField`1 templateDataField, FrameworkElement container)
   在 System.Windows.FrameworkElement.ApplyTemplate()
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.StackPanel.StackMeasureHelper(IStackMeasure measureElement, IStackMeasureScrollData scrollData, Size constraint)
   在 System.Windows.Controls.StackPanel.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   在 System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   在 System.Windows.Controls.ScrollContentPresenter.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
   在 System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
   在 System.Windows.Controls.Grid.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.ScrollViewer.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   在 System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 HandyControl.Controls.SimplePanel.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Border.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Control.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Border.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Decorator.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Documents.AdornerDecorator.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Decorator.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Controls.Primitives.PopupRoot.MeasureOverride(Size constraint)
   在 System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   在 System.Windows.UIElement.Measure(Size availableSize)
   在 System.Windows.Interop.HwndSource.SetLayoutSize()
   在 System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
   在 System.Windows.Controls.Primitives.Popup.SetRootVisualToPopupRoot()
   在 System.Windows.Controls.Primitives.Popup.CreateWindow(Boolean asyncCall)
   在 System.Windows.Controls.Primitives.Popup.OnIsOpenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   在 System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   在 System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   在 System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   在 System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   在 System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
   在 System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
   在 System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
   在 MS.Internal.Data.PropertyPathWorker.UpdateSourceValueState(Int32 k, ICollectionView collectionView, Object newValue, Boolean isASubPropertyChange)
   在 MS.Internal.Data.PropertyPathWorker.OnDependencyPropertyChanged(DependencyObject d, DependencyProperty dp, Boolean isASubPropertyChange)
   在 System.Windows.Data.BindingExpression.HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   在 System.Windows.Data.BindingExpressionBase.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   在 System.Windows.Data.BindingExpression.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   在 System.Windows.DependentList.InvalidateDependents(DependencyObject source, DependencyPropertyChangedEventArgs sourceArgs)
   在 System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   在 System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   在 System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   在 MS.Internal.Data.PropertyPathWorker.SetValue(Object item, Object value)
   在 System.Windows.Data.BindingExpression.UpdateSource(Object value)

XamlObjectWriterException: XAML 节点流: StartMember“System.Windows.Controls.ContentControl.Content”前面缺少 StartObject。
StackTrace:
   在 System.Xaml.XamlObjectWriter.WriteStartMember(XamlMember property)
   在 System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
   在 System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)