How to change the background color of the Header alone in DetailsView or Nested Grid?

The Background color for Header row can be changed by setting the SfDataGrid.HeaderStyle property for DetailsView Grid. When defining SfDataGrid.DetailsViewDefinition, you can customize the property setting of DetailsView Grid by defining GridViewDefinition.DataGrid.HeaderStyle.

In the following code example, GridHeaderCellControl style is customized for DetailsViewGrid via GridViewDefinition.DataGrid.

XAML

<Window.DataContext>
        <local:ViewModel />
    </Window.DataContext>
    <Grid>
        <syncfusion:SfDataGrid x:Name="dataGrid"
                               AutoGenerateColumns="False"
                               HideEmptyGridViewDefinition="True"
                               ItemsSource="{Binding Path=OrdersDetails}"
                              syncfusion:DetailsViewManager.DisableLastColumnResizing="True"
                               >
            <syncfusion:SfDataGrid.DetailsViewDefinition>
                <syncfusion:GridViewDefinition RelationalColumn="OrderDetails">
                    <syncfusion:GridViewDefinition.DataGrid>
                        <syncfusion:SfDataGrid x:Name="FirstDetailsViewGrid">
                            <syncfusion:SfDataGrid.HeaderStyle>
                                <Style TargetType="syncfusion:GridHeaderCellControl">
                                    <Setter Property="Background" Value="Red"/>
                                </Style>
                            </syncfusion:SfDataGrid.HeaderStyle>
                            <syncfusion:SfDataGrid.Columns>
                                <syncfusion:GridTextColumn MappingName="OrderID" />
                                <syncfusion:GridTextColumn MappingName="ProductID" />
                                <syncfusion:GridTextColumn MappingName="UnitPrice" />
                                <syncfusion:GridTextColumn MappingName="Quantity" />
                                <syncfusion:GridTextColumn MappingName="CustomerID" />
                                <syncfusion:GridTextColumn MappingName="Discount" />
                                <syncfusion:GridDateTimeColumn MappingName="OrderDate"/>
                            </syncfusion:SfDataGrid.Columns>
                        </syncfusion:SfDataGrid>
                    </syncfusion:GridViewDefinition.DataGrid>
                </syncfusion:GridViewDefinition>
            </syncfusion:SfDataGrid.DetailsViewDefinition>
            <syncfusion:SfDataGrid.Columns>
                <syncfusion:GridTextColumn MappingName="OrderID" />
                <syncfusion:GridTextColumn MappingName="CustomerID" />
                <syncfusion:GridDateTimeColumn MappingName="ShippingDate" />
                <syncfusion:GridTextColumn MappingName="EmployeeID" />
                <syncfusion:GridTextColumn MappingName="Freight" />
                <syncfusion:GridCheckBoxColumn MappingName="IsClosed" />
            </syncfusion:SfDataGrid.Columns>
        </syncfusion:SfDataGrid>
    </Grid>

When you set AutoGenerateRelations as “True”, you can customize the DetailsView Grid via the SfDataGrid.AutoGenerateRelations event.

The HeaderStyle of DetailsView is customized when AutoGenerateColumns is set to “True”.

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();           
            this.dataGrid.AutoGeneratingRelations += dataGrid_AutoGeneratingRelations;
        }        void dataGrid_AutoGeneratingRelations
                       (object sender, Syncfusion.UI.Xaml.Grid.AutoGeneratingRelationsArgs e)
        {
e.GridViewDefinition.DataGrid.HeaderStyle = (Style)this.Resources["headercolor"]; 
              }
    }

Here, you can see that the Header’s Background color has been changed for DetailsView Grid.

Header Background color changed