Datagrid - ItemsPresenter - vertical Scrollviewer

Question

Hello Stackoverflow Members,

i'm new! sorry for the quick an short problem. But i need your help! i have a Datagrid with 2000 rows. (grouped on CustomerNbr)

vb.net
Dim grouped As New ListCollectionView(full_list)
grouped.GroupDescriptions.Add(New PropertyGroupDescription("CustNbr"))
Datagrid.ItemsSource = grouped

This code worked fine

<DataGrid.GroupStyle>
    <GroupStyle>
        <GroupStyle.HeaderTemplate>
            <DataTemplate>
                <StackPanel>
                    <TextBlock Text="{Binding Path=Name}" />
                </StackPanel>
            </DataTemplate>
        </GroupStyle.HeaderTemplate>
        <GroupStyle.ContainerStyle>
            <Style TargetType="{x:Type GroupItem}">
                <Setter Property="Template" >
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type GroupItem}">
                            <Expander MaxHeight="400" FontWeight="Bold" Background="{Binding Path=Items, Converter={StaticResource convert_Backcolor}}" >
                                <Expander.Header>
                                    <StackPanel Orientation="Horizontal" >
                                        <TextBlock Text="{Binding Path=Name}" Margin="10,0,10,0" />
                                        <TextBlock Text="{Binding Path=Items, Converter={StaticResource convert_Cust_Name}}" MinWidth="300" Margin="10,0,10,0" />
                                        <TextBlock Text="{Binding Path=Items, Converter={StaticResource convert_Summe},ConverterCulture=de-DE, StringFormat={}{0:n2}}" HorizontalAlignment="Right" Margin="40,0,0,0" />
                                    </StackPanel>
                            </Expander.Header>
                                <ItemsPresenter />
                        </Expander>
                    </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </GroupStyle.ContainerStyle>
    </GroupStyle>
</DataGrid.GroupStyle>

But when i add a scrollviewer at the ItemsPresenter i get an error:

<ScrollViewer>  
    <ItemsPresenter />  
</ScrollViewer>

the error comes, when i make the second grouped custnbr screen

Error: invalidOperationExeption was unhandled

I need the ScrollViewer because i have so many invoices on the CustNbr. The Problem is in Expander. In Expander.Content the vertical ScrollViewer is not support or something...

can anybody help me?

Answer 1

SOLUTION: in Datagrid Header this statements are not allowed: CanUserAddRows="False" CanUserDeleteRows="False" IsReadOnly="True"

also see here: https://blogs.msdn.microsoft.com/vinsibal/2008/10/01/overview-of-the-editing-features-in-the-wpf-datagrid/