我有一个奇怪的情况，我不知道如何处理......在我的项目中，我有以下 TreeView，它在其 TreeViewItem 中包含复选框：
<DataGrid x:Name="dataGridVirtualMachinesInfo" ItemsSource="{Binding Path=SelectedItem.VMImagesInfo, ElementName=comboBoxUserName}"
Style="{DynamicResource RoundDataGridStyle}" RowDetailsVisibilityChanged="dataGridVirtualMachinesInfo_RowDetailsVisibilityChanged"
MouseLeftButtonUp="DataGrid_MouseLeftButtonUp" CanUserAddRows="False" Margin="24" AutoGenerateColumns="False" ClipToBounds="True"
AreRowDetailsFrozen="false" CanUserResizeRows="False" RowDetailsTemplate="{DynamicResource VMRowDetailsDataTemplate}"
Visibility="Visible" Background="White" VerticalAlignment="Top">
<DataGrid.Resources>
<DataTemplate x:Key="VMRowDetailsDataTemplate">
<Border BorderThickness="2">
<Border.BorderBrush>
<SolidColorBrush Color="{DynamicResource ColorBorder}"/>
</Border.BorderBrush>
<Grid x:Name="gridRowDetail" Height="450" Width="Auto" Margin="0" Background="White" VerticalAlignment="Stretch" >
<Grid.RowDefinitions>
<RowDefinition Height="2*"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="10*"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="5*"/>
</Grid.RowDefinitions>
<Grid x:Name="gridCurrentVersion" Margin="0" Grid.RowSpan="1" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Label x:Name="lableCurrentVersion" Content="Current Version : " HorizontalAlignment="Left"
Margin="5,0,0,0" VerticalAlignment="Center" Width="Auto" FontWeight="Bold"/>
<TextBox x:Name="textBoxCurrentVersion" Text="{Binding CurrentVersion}" HorizontalAlignment="Left"
Margin="105,0,0,0" TextWrapping="Wrap" VerticalAlignment="Center" RenderTransformOrigin="0.432,0.365"
Width="100" Height="Auto" Grid.Column="0" AcceptsReturn="True"/>
<Button x:Name="buttonRestoreDefaults" Content="Restore Defaults" HorizontalAlignment="Right"
Margin="0,2,95,2" VerticalAlignment="Center" Width="90" RenderTransformOrigin="0.213,-0.401" Grid.Column="0"
d:LayoutOverrides="HorizontalAlignment, GridBox" Height="30" Grid.ColumnSpan="2"/>
<Button x:Name="buttonSaveInfo" Content="Save Info" Click="buttonSaveInfo_Click" Width="90"
Background="#FF2DD420" Margin="0,2" HorizontalAlignment="Right" Height="30"
VerticalAlignment="Center" RenderTransformOrigin="1.125,0.599" Grid.Column="1"/>
</Grid>
<GridSplitter x:Name="gridSplitterCurrVerAndSaveInfoButton"
ResizeDirection="Rows"
Grid.Column="0"
Grid.ColumnSpan="2"
Grid.Row="1"
Width="Auto"
Height="3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Margin="0">
<GridSplitter.Background>
<SolidColorBrush Color="{DynamicResource ColorBorder}"/>
</GridSplitter.Background>
</GridSplitter>
<Grid x:Name="gridFeaturesAndProps" Margin="0" Grid.Row="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="3*"/>
</Grid.ColumnDefinitions>
<Grid x:Name="gridFeatures">
<Grid.RowDefinitions>
<RowDefinition Height="2*"/>
<RowDefinition Height="15*"/>
</Grid.RowDefinitions>
<Label x:Name="lableFeaturesSelection" Content="Features Selection" HorizontalAlignment="Left"
VerticalAlignment="Top" FontWeight="Bold" Grid.Row="0" Margin="5,0,0,0"/>
<TreeView x:Name="GroupViewFeaturesList" ItemsSource="{Binding Path=InstallPackage.Features.FeaturesTree}"
ItemContainerStyle="{DynamicResource TreeViewItemStyle}"
Margin="5,0,0,5" FontFamily="Pescadero" BorderThickness="0" FontSize="13.333"
Width="Auto" Height="Auto" Grid.Row="1" VerticalAlignment="Stretch" d:LayoutOverrides="GridBox">
<TreeView.Resources>
<Style x:Key="TreeViewItemStyle" TargetType="{x:Type TreeViewItem}">
<!--<Setter Property="Visibility" Value="{Binding Path=IsVisible, Mode=TwoWay, Converter={StaticResource boolToVis}}" />-->
<Setter Property="IsExpanded" Value="True" />
</Style>
<HierarchicalDataTemplate DataType="{x:Type nsMsiObjects:Feature}" ItemsSource="{Binding SubFeatures}">
<CheckBox x:Name="checkBoxFeatureSelection" Content="{Binding DisplayName}" Checked="checkBoxFeatureSelection_Checked"/>
</HierarchicalDataTemplate>
</TreeView.Resources>
<TreeView.Background>
<LinearGradientBrush EndPoint="1.204,0.5" StartPoint="0.056,0.5">
<GradientStop Color="White" Offset="1"/>
<GradientStop Color="#FFD4D7DB"/>
</LinearGradientBrush>
</TreeView.Background>
</TreeView>
</Grid>
<GridSplitter x:Name="gridSplitterFeaturesAndInstallProps"
ResizeDirection="Rows"
Grid.Column="1"
Grid.RowSpan="2"
Grid.Row="0"
Width="3"
Height="Auto"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Margin="4,0">
<GridSplitter.Background>
<SolidColorBrush Color="{DynamicResource ColorBorder}"/>
</GridSplitter.Background>
</GridSplitter>
<Grid x:Name="gridInstallPropsAndExpendAdditionals" Margin="0" Grid.Column="2">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid x:Name="gridInstallProps" Grid.Column="0" Margin="0" Width="Auto">
<Grid.RowDefinitions>
<RowDefinition Height="2*"/>
<RowDefinition Height="15*"/>
</Grid.RowDefinitions>
<Label x:Name="lableInstallationProperties" Content="Installation Properties" HorizontalAlignment="Left"
Margin="0" d:LayoutOverrides="GridBox" Grid.Row="0" Grid.Column="0" FontWeight="Bold" VerticalAlignment="Top"/>
<ScrollViewer Grid.Row="1">
<StackPanel x:Name="StackPanelInstallProps" Width="Auto" Height="Auto">
<!--<nsProject:ExpanderInstallProperties x:Name="expanderInstallProps" />-->
</StackPanel>
</ScrollViewer>
</Grid>
</Grid>
</Grid>
<GridSplitter x:Name="gridSplitterFeaturesAndComments"
ResizeDirection="Rows"
Grid.Column="0"
Grid.ColumnSpan="2"
Grid.Row="3"
Width="Auto"
Height="3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Margin="0">
<GridSplitter.Background>
<SolidColorBrush Color="{DynamicResource ColorBorder}"/>
</GridSplitter.Background>
</GridSplitter>
<Grid x:Name="gridComments" HorizontalAlignment="Stretch" Margin="0" Width="Auto" Grid.Row="4">
<Grid.RowDefinitions>
<RowDefinition Height="2*"/>
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Label x:Name="lableComments" Content="Comments :" HorizontalAlignment="Left"
VerticalAlignment="Top" Width="Auto" FontWeight="Bold" Grid.Row="0" Grid.RowSpan="1"
Margin="5,0,33.866,-200" d:LayoutOverrides="Width"/>
<TextBox x:Name="textBoxComments" Text="{Binding UserComments}" Margin="5" TextWrapping="Wrap"
VerticalAlignment="Stretch" Height="Auto" VerticalScrollBarVisibility="Auto" Grid.Row="1"
BorderThickness="3" AcceptsReturn="True" MaxWidth="{Binding ActualWidth, ElementName=gridComments}"/>
</Grid>
</Grid>
</Border>
</DataTemplate>
</DataGrid.Resources>
<DataGrid.RowBackground>
<LinearGradientBrush EndPoint="0.5,1" MappingMode="RelativeToBoundingBox" StartPoint="0.5,0">
<GradientStop Color="#FFB7CADE"/>
<GradientStop Color="#FF5F6264" Offset="1"/>
</LinearGradientBrush>
</DataGrid.RowBackground>
<DataGrid.Columns>
<DataGridTextColumn x:Name="dgTextColumnServerIP" Binding="{Binding VMServerIP}" Header="Server IP" IsReadOnly="True"/>
<DataGridTextColumn x:Name="dgTextColumnVMName" Binding="{Binding Name}" Header="Virtual Machine Name" IsReadOnly="True"/>
<DataGridTextColumn x:Name="dgTextColumnInstalledVersion" Binding="{Binding InstalledVersion}" Header="Installed Version"/>
<DataGridTemplateColumn x:Name="dgTemplateColumnUpgradeMajorVersion" Header="Upgrade Major Version">
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ComboBox x:Name="comboBoxMajorVersion" Height="Auto"
SelectedIndex="0"
ItemsSource="{Binding Path=InstallPackage.Versions,UpdateSourceTrigger=PropertyChanged}"
/>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox x:Name="comboBoxMajorVersion" Height="Auto"
SelectedIndex="0"
ItemsSource="{Binding Path=InstallPackage.Versions}"
/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="dgTemplateColumnUpgradeVersion" Header="Upgrade Version">
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ComboBox x:Name="comboBoxMinorVersion"
SelectedIndex="0"
ItemsSource="{Binding Path=SelectedItem.MinorBuildVersions, ElementName=comboBoxMajorVersion, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
DisplayMemberPath="Version"
SelectedValue="Version"
SelectedValuePath="Version"
Margin="15,0,0,0" VerticalAlignment="Center" IsEditable="True" IsReadOnly="True"
ToolTip="Choose user to display his virtual machines" Grid.Column="3" Width="220" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox x:Name="comboBoxMinorVersion"
SelectedIndex="0"
ItemsSource="{Binding Path=SelectedItem.Users, ElementName=comboBoxTeamName, UpdateSourceTrigger=PropertyChanged}"
DisplayMemberPath="Name"
SelectedValuePath="Name"
Margin="15,0,0,0" VerticalAlignment="Center" IsEditable="True" IsReadOnly="True"
ToolTip="Choose user to display his virtual machines" Grid.Column="3" Width="220" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="dgTemplateColumnUpgradeTypr" Header="Upgrade Type">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox Height="Auto"
ItemsSource="{StaticResource UpgradeTypeList}"
SelectedItem="{Binding UpgradeType}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="dgTemplateColumnExecuteUpgrade" Header="Execute Upgrade">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button Style="{StaticResource GlassButton}" Content="Go!" Width="25" Height="25" Background="#FF2DD420" Margin="2"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
但是，当我突然扩展我的数据网格的行时，抛出了一个没有源代码的 NullReferenceException，所以我看不到它是从哪里抛出的。我认为由于某种原因它会在我设置 TreeView ItemsSource 时在创建复选框之前触发事件
这是用于设置 TreeView ItemsSource 的附加代码：
/// <summary>
/// This function occur when selecting one of the rows from dataGridVirtualMachinesInfo
/// opening its row details and setting its inner controls
/// </summary>
private void dataGridVirtualMachinesInfo_RowDetailsVisibilityChanged(object sender, DataGridRowDetailsEventArgs e)
{
string path = "Some Path.msi";
TreeView featuresTree = dataGridVirtualMachinesInfo.GetRowDetailsInnerControl<TreeView>("GroupViewFeaturesList");
if (featuresTree.Items.IsEmpty)
{
// get the selected row of dataGridVirtualMachinesInfo
DataGridRow dgRow = dataGridVirtualMachinesInfo.GetSelectedRow(dataGridVirtualMachinesInfo.SelectedItem);
VMImageInfo selectedRowVmInfo = dgRow.DataContext as VMImageInfo;
selectedRowVmInfo.InstallPackage = new InstallationPackage();
selectedRowVmInfo.InstallPackage.SetFeatures(path); DisplayFeaturesGroupedByFeatures(selectedRowVmInfo.InstallPackage.Features.DisplayedFeaturesList);
}
}
我该如何处理？我整天都在寻找答案，但找不到与此相关的东西
谢谢！
更新： 我已经按照您的要求添加了所有 DataGrid 及其详细信息另外您是对的，我不需要在后面的代码中设置 TreeView，所以我从那里删除了它并更改了 xaml 中的绑定路径。树视图是 DataGridRowDetails 模板的一部分 异常消息是：“对象引用未设置为对象的实例。” 由于源不可用，因此没有堆栈跟踪，可能发生在 xaml
再次感谢！