Question

I am having some some problems using the LayoutSplitter and DockLayoutManger from DevExpress.

 dxdo:DockLayoutManager>
            <dxdo:DockLayoutManager.LayoutRoot>
                <dxdo:LayoutGroup Orientation="Vertical" Height="*">
                    <dxdo:LayoutGroup Orientation="Vertical" Height="*">
                        <dxdo:DocumentPanel>
                            <Grid VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="*"></RowDefinition>
                                </Grid.RowDefinitions>
                                <ContentControl Grid.Row="0"  Content="{Binding SomeViewModel}" ContentTemplateSelector="{StaticResource templateSelector}"/>
                            </Grid>
                        </dxdo:DocumentPanel>
                    </dxdo:LayoutGroup>

                    <dxdo:LayoutGroup Height="Auto" Orientation="Vertical">
                            <dxdo:LayoutSplitter/>
                    </dxdo:LayoutGroup>

                    <dxdo:LayoutGroup>
                        <dxdo:LayoutPanel Height="Auto" AllowDock="True">
                            <ItemsControl ItemsSource="{Binding SomeViewModel.SomeCollection}" ItemTemplateSelector="{StaticResource templateSelector}">
                            </ItemsControl>
                        </dxdo:LayoutPanel>
                    </dxdo:LayoutGroup>   

                </dxdo:LayoutGroup>

            </dxdo:DockLayoutManager.LayoutRoot>

       </dxdo:DockLayoutManager>

The LayoutSplitter isn’t moving up and down. It just remains static.
With the DockLayoutManager, the 3rd nested LayoutGroup, when I remove a component from it, I can’t drop the component back in. A hint would be great thanks!

Answer 1

The LayoutSplitter control is needed to split layout groups or layout control items. It can’t be used with LayoutPanels or DocumentPanels. Moreover it is not needed to use splitters with dock items because these items resizing are automatically provided by the DockLayoutManager. You should also use the DocumentPanel as child item for the DocumentGroup instead of placing that document directly to the LayoutGroup.Items collection. Or use the LayoutPanel instead of the DocumentPanel.
So, you markup should looks like this:

<dxdo:DockLayoutManager>
    <dxdo:LayoutGroup Orientation="Vertical" >
        <dxdo:DocumentGroup>
            <dxdo:DocumentPanel Caption="Document">
                <!-- Document content -->
            </dxdo:DocumentPanel>
        </dxdo:DocumentGroup>
        <dxdo:LayoutGroup>
            <dxdo:LayoutPanel Caption="Panel">
                <!-- Panel content -->
            </dxdo:LayoutPanel>
        </dxdo:LayoutGroup>
    </dxdo:LayoutGroup>
</dxdo:DockLayoutManager>

You can read more in these articles:

1. Dock Layout Manager Fundamentals
2. Layout Groups
3. Dock Items
4. Layout Items
5. Document Groups and Panels