Master/Detail DataGrid. How to access Detail DataGrid to set ItemsSource?

Question

In a typical Master/Detail situation...

I have a DataGrid. The ItemsSource of this DataGrid is set in the Completed event of a WCF call - (grdMaster.ItemsSource = e.Result) - where the x:Name of the grid is grdMaster. This is all 100%.

However, when adding a Detail Datagrid inside the master grids DataTemplate and naming it appropriately... my codebehind does not recognise the detail grid. So plainly put, I cannot set the ItemsSource of grdDetail like I do with grdMaster.

Depending on the Master item selected, I need to do a WCF call to get the appropriate Details.

user302084 user302084 · Accepted Answer · 2011-10-03T21:03:43

Depending on how you are being notified that an item is being selected for expansion you will need to find the row the user is in:

DataGridRow row = DataGridRow.GetRowContainingElement(...);

and update the row details visibility:

row.DetailsVisibility = Visibility.Visible;

Those details aside, you need to create a style for the details rows -- which is wired to an event you can listen to:

<DataTemplate x:Key="DetailsRowTemplate">
    <StackPanel>
        <Border BorderBrush="{StaticResource BlackBrush}" BorderThickness="0,2,0,0" Padding="0" >
            <data:DataGrid ItemsSource="{Binding DummyResultsView}" AutoGenerateColumns="False"
                            LoadingRow="DataGrid_LoadingRow" 
                            CanUserResizeColumns="False" 
                            CanUserReorderColumns="False"
                            HeadersVisibility="None"
                            IsReadOnly="True">
            </data:DataGrid>
        </Border>
    </StackPanel>
</DataTemplate>

which is set as the RowDetailsTemplate for your grid:

Within the LoadingRow event you can obtain a reference to which data context is involved, and save a reference to the child data grid so that after a WCF call you can set the ItemsSource:

private void DataGrid_LoadingRowDetails(object sender, DataGridRowDetailsEventArgs e)
{
    List<DataGrid> detailElements = e.DetailsElement.GetChildrenByType<System.Windows.Controls.DataGrid>().ToList();

    var itemSelected = e.Row.DataContext;

    if (detailElements.Count > 0)
    {
        DataGrid detailsDataGrid = detailElements[0];

        // save a reference so the ItemsSource can be set later....
        this.DataGrid = detailsDataGrid;

        this.Model.InitializeDetailsList(detailsDataGrid, itemSelected);
    }
}

Hope that helps,

Master/Detail DataGrid. How to access Detail DataGrid to set ItemsSource?

1 Answers