Change TextBlock of custom Grid - wpf

Question

<Grid Grid.IsSharedSizeScope="True" Name="treeGrid" Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="3">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition />
</Grid.RowDefinitions>
<Grid.Resources>
<local:LevelConverter x:Key="levelConverter" />
<HierarchicalDataTemplate ItemsSource="{Binding Items}"
DataType="{x:Type local:DirectoryRecord}">
<Grid ShowGridLines="False">
<Grid.ColumnDefinitions>
<ColumnDefinition SharedSizeGroup="rowHeaderColumn"/>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition SharedSizeGroup="column1"/>
<ColumnDefinition SharedSizeGroup="column2"/>
<ColumnDefinition SharedSizeGroup="column3"/>
<ColumnDefinition SharedSizeGroup="column4"/>
<ColumnDefinition SharedSizeGroup="column5"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0"
Text="{Binding Name}"></TextBlock>
<Rectangle Grid.Column="1">
<Rectangle.Width>
<MultiBinding Converter="{StaticResource levelConverter}">
<Binding Path="Level"></Binding>
<Binding ElementName="treeViewItemToMeasure" Path="ActualWidth"></Binding>
</MultiBinding>
</Rectangle.Width>
</Rectangle>
<TextBlock Grid.Column="2"
Text="{Binding LastAccessed}"></TextBlock>
<TextBlock Grid.Column="3"
Text="{Binding Files.Count}"></TextBlock>
<TextBlock Grid.Column="4"
Text="{Binding Inherited}"></TextBlock>
<Grid.Style>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Background" Value="Aquamarine" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Inherited}" Value="True">
<Setter Property="Background" Value="Black" />
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Style>
</Grid>
</HierarchicalDataTemplate>
</Grid.Resources>
<TreeView>
<!-- My binding goes here -->
</TreeView>
</Grid>
I'm trying to change the background of the TextBlock contained within my custom Grid(TreeGrid), however this code fails with XamlParseException
'TextBlock' TargetTypes does not match type of element 'Grid'.

Answer 1

Instead of defining a style inside a Grid.Style section, you have to declare it as the Grid.Resource Style, with the TargetType specified, i.e.
<Grid.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Background" Value="Aquamarine" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Inherited}" Value="True">
<Setter Property="Background" Value="Black" />
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Resources>