刷新 DataGrid 导致 NullReferenceException
Refreshing DataGrid causes NullReferenceException
我有一个数据网格：
<DataGrid Style="{StaticResource MaterialDesignDataGrid}" ItemsSource="{Binding AllSales, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True}" x:Name="salesData"
materialDesign:DataGridAssist.CellPadding="5" Background="White" GridLinesVisibility="All"
VerticalGridLinesBrush="LightGray" HorizontalGridLinesBrush="LightGray" BorderThickness="0.1"
CanUserDeleteRows="False" CanUserReorderColumns="False" CanUserResizeRows="False" CanUserSortColumns="False" Cursor="Arrow"
CanUserResizeColumns="False" CanUserAddRows="False" ColumnWidth="*" AutoGenerateColumns="False" d:ItemsSource="{d:SampleData ItemCount=5}" >
通过从后端检索数据填充：
private async void searchFilter_Click(object sender, RoutedEventArgs e)
{
try
{
salesVM.DashBoardVM.IsLoading = true;
int idDepartment = salesVM.DashBoardVM.MainVM.Device.IdDepartment;
string from = fromDateTxt.Text;
string to = toDateTxt.Text;
var filter = salesVM.SimpleFilterViewModel;
salesVM.AllSales.Clear();
//salesData.Items.Refresh();
var report = await Task.Run(() => salesVM.DashBoardVM.MainVM.APIService.Reports.SalesReport(idDepartment, from, to, filter.SelectedCategoryIds, filter.SelectedGroupIds));
if (report != null)
{
if (report.Sales != null)
{
salesVM.AllSales.AddRange(report.Sales);
//salesData.Items.Refresh();
ICollectionView collectionView = CollectionViewSource.GetDefaultView(salesData.ItemsSource);
if (collectionView != null && collectionView.CanGroup == true)
{
collectionView.GroupDescriptions.Clear();
collectionView.GroupDescriptions.Add(new PropertyGroupDescription("CategoryName"));
}
}
}
salesVM.DashBoardVM.IsLoading = false;
}
catch (Exception ex)
{
}
}
绑定 属性 是：
private ObservableCollection<Sale> allSales;
public ObservableCollection<Sale> AllSales
{
get { return allSales; }
set
{
allSales = value;
OnPropertyChanged(new PropertyChangedEventArgs("AllSales"));
}
}
当我多次检索数据（通常是 1-2 次）时，它运行良好。第 3 次后，当我想清除网格时，在检索新数据时它会在在线重置集合时抛出 NullReferenceException：
salesVM.AllSales.Clear()
AllSales 永远不会为空，最初为空。 StackTrace 是：
at System.Windows.StyleHelper.UpdateTables(PropertyValue& propertyValue, FrugalStructList`1& childRecordFromChildIndex, FrugalStructList`1& triggerSourceRecordFromChildIndex, FrugalStructList`1& resourceDependents, HybridDictionary& dataTriggerRecordFromBinding, HybridDictionary childIndexFromChildName, Boolean& hasInstanceValues)
at System.Windows.TemplateContent.ParseXaml()
at System.Windows.FrameworkTemplate.set_Template(TemplateContent value)
at System.Windows.Baml2006.WpfSharedBamlSchemaContext.<>c.<Create_BamlProperty_FrameworkTemplate_Template>b__277_0(Object target, Object value)
at System.Windows.Baml2006.WpfKnownMemberInvoker.SetValue(Object instance, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(XamlMember member, Object obj, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.SetValue(Object obj, XamlMember property, Object value)
at System.Xaml.XamlObjectWriter.Logic_ApplyPropertyValue(ObjectWriterContext ctx, XamlMember prop, Object value, Boolean onParent)
at System.Xaml.XamlObjectWriter.Logic_DoAssignmentToParentProperty(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.WriteEndMember()
at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.LoadDeferredContent(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings parentSettings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.DeferredResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DeferredAppResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.StaticResourceExtension.TryProvideValueImpl(IServiceProvider serviceProvider, Boolean allowDeferredReference, Boolean mustReturnDeferredResourceReference)
at System.Windows.StaticResourceExtension.ProvideValueInternal(IServiceProvider serviceProvider, Boolean allowDeferredReference)
at System.Windows.StaticResourceExtension.ProvideValue(IServiceProvider serviceProvider)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
at System.Xaml.XamlObjectWriter.Logic_ProvideValue(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.Logic_AssignProvidedValue(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.WriteEndMember()
at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.LoadDeferredContent(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings parentSettings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.FetchResource(Object resourceKey, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference, Boolean canCacheAsThemeResource, Boolean& canCache)
at System.Windows.FrameworkElement.FindResourceInternal(FrameworkElement fe, FrameworkContentElement fce, DependencyProperty dp, Object resourceKey, Object unlinkedParent, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference, DependencyObject boundaryElement, Boolean isImplicitStyleLookup, Object& source)
at System.Windows.FrameworkElement.FindImplicitStyleResource(FrameworkElement fe, Object resourceKey, Object& source)
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, Boolean preserveCurrentValue)
at System.Windows.FrameworkElement.UpdateStyleProperty()
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, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at MS.Internal.PrePostDescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
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.EnsureEmptyChildren(FrameworkElement logicalParent)
at System.Windows.Controls.Panel.OnItemsChangedInternal(Object sender, ItemsChangedEventArgs args)
at System.Windows.Controls.VirtualizingPanel.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.WeakEventManager.ListenerList`1.DeliverEvent(Object sender, EventArgs e, Type managerType)
at System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
at System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.HandleCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.ClearItems()
at System.Collections.ObjectModel.Collection`1.Clear()
at MS.Internal.Data.CollectionViewGroupInternal.Clear()
at System.Windows.Data.ListCollectionView.PrepareShaping()
at System.Windows.Data.ListCollectionView.PrepareLocalArray()
at System.Windows.Data.ListCollectionView.RefreshOverride()
at System.Windows.Data.CollectionView.RefreshInternal()
at System.Windows.Data.CollectionView.RefreshOrDefer()
at System.Windows.Data.ListCollectionView.ProcessCollectionChanged(NotifyCollectionChangedEventArgs args)
at System.Windows.Data.CollectionView.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.ClearItems()
at System.Collections.ObjectModel.Collection`1.Clear()
at ReportApp.Views.Reports.Sales.SalesReportControl.<searchFilter_Click>d__13.MoveNext() in C:\Users\user\source\repos\ReportApp\Views\Reports\Sales\SalesReportControl.xaml.cs:line 261
非常感谢任何帮助。
未找到确切原因，但已通过更改数据网格分组样式修复：
<Expander x:Name="exp" IsExpanded="True" BorderBrush="DimGray" BorderThickness="0">
<Expander.Header>
<DockPanel>
<TextBlock FontWeight="DemiBold" FontSize="18" Text="{Binding Path=Name}" />
</DockPanel>
</Expander.Header>
<Expander.Content>
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<ItemsPresenter />
<TextBlock Grid.Row="1" Style="{StaticResource MaterialDesignBody2TextBlock}" FontSize="16" FontWeight="Normal" Padding="5"
Text="{Binding Path=Items, Converter={StaticResource groupTotals}}" HorizontalAlignment="Right"/>
</Grid>
</Expander.Content>
</Expander>
对此：
<Border BorderBrush="DimGray" BorderThickness="0">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<TextBlock FontWeight="DemiBold" FontSize="18" Text="{Binding Path=Name}" Margin="10,0,0,0"/>
<ToggleButton HorizontalAlignment="Right" Style="{StaticResource MaterialDesignExpanderToggleButton}" Margin="0,0,10,0" x:Name="toggle"
IsChecked="True">
<materialDesign:PackIcon Kind="ChevronDown"/>
</ToggleButton>
</Grid>
<StackPanel Orientation="Vertical" Grid.Row="1" Visibility="{Binding ElementName=toggle, Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter}}">
<ItemsPresenter />
<TextBlock Grid.Row="1" Style="{StaticResource MaterialDesignBody2TextBlock}" FontSize="16" FontWeight="Normal" Padding="5"
Text="{Binding Path=Items, Converter={StaticResource groupTotals}}" HorizontalAlignment="Right"/>
</StackPanel>
</Grid>
</Border>
我有一个数据网格：
<DataGrid Style="{StaticResource MaterialDesignDataGrid}" ItemsSource="{Binding AllSales, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True}" x:Name="salesData"
materialDesign:DataGridAssist.CellPadding="5" Background="White" GridLinesVisibility="All"
VerticalGridLinesBrush="LightGray" HorizontalGridLinesBrush="LightGray" BorderThickness="0.1"
CanUserDeleteRows="False" CanUserReorderColumns="False" CanUserResizeRows="False" CanUserSortColumns="False" Cursor="Arrow"
CanUserResizeColumns="False" CanUserAddRows="False" ColumnWidth="*" AutoGenerateColumns="False" d:ItemsSource="{d:SampleData ItemCount=5}" >
通过从后端检索数据填充：
private async void searchFilter_Click(object sender, RoutedEventArgs e)
{
try
{
salesVM.DashBoardVM.IsLoading = true;
int idDepartment = salesVM.DashBoardVM.MainVM.Device.IdDepartment;
string from = fromDateTxt.Text;
string to = toDateTxt.Text;
var filter = salesVM.SimpleFilterViewModel;
salesVM.AllSales.Clear();
//salesData.Items.Refresh();
var report = await Task.Run(() => salesVM.DashBoardVM.MainVM.APIService.Reports.SalesReport(idDepartment, from, to, filter.SelectedCategoryIds, filter.SelectedGroupIds));
if (report != null)
{
if (report.Sales != null)
{
salesVM.AllSales.AddRange(report.Sales);
//salesData.Items.Refresh();
ICollectionView collectionView = CollectionViewSource.GetDefaultView(salesData.ItemsSource);
if (collectionView != null && collectionView.CanGroup == true)
{
collectionView.GroupDescriptions.Clear();
collectionView.GroupDescriptions.Add(new PropertyGroupDescription("CategoryName"));
}
}
}
salesVM.DashBoardVM.IsLoading = false;
}
catch (Exception ex)
{
}
}
绑定 属性 是：
private ObservableCollection<Sale> allSales;
public ObservableCollection<Sale> AllSales
{
get { return allSales; }
set
{
allSales = value;
OnPropertyChanged(new PropertyChangedEventArgs("AllSales"));
}
}
当我多次检索数据（通常是 1-2 次）时，它运行良好。第 3 次后，当我想清除网格时，在检索新数据时它会在在线重置集合时抛出 NullReferenceException：
salesVM.AllSales.Clear()
AllSales 永远不会为空，最初为空。 StackTrace 是：
at System.Windows.StyleHelper.UpdateTables(PropertyValue& propertyValue, FrugalStructList`1& childRecordFromChildIndex, FrugalStructList`1& triggerSourceRecordFromChildIndex, FrugalStructList`1& resourceDependents, HybridDictionary& dataTriggerRecordFromBinding, HybridDictionary childIndexFromChildName, Boolean& hasInstanceValues)
at System.Windows.TemplateContent.ParseXaml()
at System.Windows.FrameworkTemplate.set_Template(TemplateContent value)
at System.Windows.Baml2006.WpfSharedBamlSchemaContext.<>c.<Create_BamlProperty_FrameworkTemplate_Template>b__277_0(Object target, Object value)
at System.Windows.Baml2006.WpfKnownMemberInvoker.SetValue(Object instance, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(XamlMember member, Object obj, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.SetValue(Object obj, XamlMember property, Object value)
at System.Xaml.XamlObjectWriter.Logic_ApplyPropertyValue(ObjectWriterContext ctx, XamlMember prop, Object value, Boolean onParent)
at System.Xaml.XamlObjectWriter.Logic_DoAssignmentToParentProperty(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.WriteEndMember()
at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.LoadDeferredContent(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings parentSettings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.DeferredResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DeferredAppResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.StaticResourceExtension.TryProvideValueImpl(IServiceProvider serviceProvider, Boolean allowDeferredReference, Boolean mustReturnDeferredResourceReference)
at System.Windows.StaticResourceExtension.ProvideValueInternal(IServiceProvider serviceProvider, Boolean allowDeferredReference)
at System.Windows.StaticResourceExtension.ProvideValue(IServiceProvider serviceProvider)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
at System.Xaml.XamlObjectWriter.Logic_ProvideValue(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.Logic_AssignProvidedValue(ObjectWriterContext ctx)
at System.Xaml.XamlObjectWriter.WriteEndMember()
at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.LoadDeferredContent(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings parentSettings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.FetchResource(Object resourceKey, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference, Boolean canCacheAsThemeResource, Boolean& canCache)
at System.Windows.FrameworkElement.FindResourceInternal(FrameworkElement fe, FrameworkContentElement fce, DependencyProperty dp, Object resourceKey, Object unlinkedParent, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference, DependencyObject boundaryElement, Boolean isImplicitStyleLookup, Object& source)
at System.Windows.FrameworkElement.FindImplicitStyleResource(FrameworkElement fe, Object resourceKey, Object& source)
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, Boolean preserveCurrentValue)
at System.Windows.FrameworkElement.UpdateStyleProperty()
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, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at MS.Internal.PrePostDescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
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.EnsureEmptyChildren(FrameworkElement logicalParent)
at System.Windows.Controls.Panel.OnItemsChangedInternal(Object sender, ItemsChangedEventArgs args)
at System.Windows.Controls.VirtualizingPanel.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.WeakEventManager.ListenerList`1.DeliverEvent(Object sender, EventArgs e, Type managerType)
at System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
at System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ReadOnlyObservableCollection`1.HandleCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.ClearItems()
at System.Collections.ObjectModel.Collection`1.Clear()
at MS.Internal.Data.CollectionViewGroupInternal.Clear()
at System.Windows.Data.ListCollectionView.PrepareShaping()
at System.Windows.Data.ListCollectionView.PrepareLocalArray()
at System.Windows.Data.ListCollectionView.RefreshOverride()
at System.Windows.Data.CollectionView.RefreshInternal()
at System.Windows.Data.CollectionView.RefreshOrDefer()
at System.Windows.Data.ListCollectionView.ProcessCollectionChanged(NotifyCollectionChangedEventArgs args)
at System.Windows.Data.CollectionView.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.ClearItems()
at System.Collections.ObjectModel.Collection`1.Clear()
at ReportApp.Views.Reports.Sales.SalesReportControl.<searchFilter_Click>d__13.MoveNext() in C:\Users\user\source\repos\ReportApp\Views\Reports\Sales\SalesReportControl.xaml.cs:line 261
非常感谢任何帮助。
未找到确切原因，但已通过更改数据网格分组样式修复：
<Expander x:Name="exp" IsExpanded="True" BorderBrush="DimGray" BorderThickness="0">
<Expander.Header>
<DockPanel>
<TextBlock FontWeight="DemiBold" FontSize="18" Text="{Binding Path=Name}" />
</DockPanel>
</Expander.Header>
<Expander.Content>
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<ItemsPresenter />
<TextBlock Grid.Row="1" Style="{StaticResource MaterialDesignBody2TextBlock}" FontSize="16" FontWeight="Normal" Padding="5"
Text="{Binding Path=Items, Converter={StaticResource groupTotals}}" HorizontalAlignment="Right"/>
</Grid>
</Expander.Content>
</Expander>
对此：
<Border BorderBrush="DimGray" BorderThickness="0">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<TextBlock FontWeight="DemiBold" FontSize="18" Text="{Binding Path=Name}" Margin="10,0,0,0"/>
<ToggleButton HorizontalAlignment="Right" Style="{StaticResource MaterialDesignExpanderToggleButton}" Margin="0,0,10,0" x:Name="toggle"
IsChecked="True">
<materialDesign:PackIcon Kind="ChevronDown"/>
</ToggleButton>
</Grid>
<StackPanel Orientation="Vertical" Grid.Row="1" Visibility="{Binding ElementName=toggle, Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter}}">
<ItemsPresenter />
<TextBlock Grid.Row="1" Style="{StaticResource MaterialDesignBody2TextBlock}" FontSize="16" FontWeight="Normal" Padding="5"
Text="{Binding Path=Items, Converter={StaticResource groupTotals}}" HorizontalAlignment="Right"/>
</StackPanel>
</Grid>
</Border>