Usage of GridSplitter with WindowsFormsHost. Problem with proportional sizing (*)

Question

I've got a UserControlParent, which has a UserControlSon and a GridSplitter (All inside Grid).

GridSplitter divides UserControlParent into two parts:

• UserControlSon
• SomeOtherPart

UserControlSon has a WindowsFormsHost inside, it is created dynamically. WindowsFormsHost has CeTe.Dynamic PDFViewer (WinForms) control as a child inside.

When I try to use GridSplitter to change UserControlParent.Grid.Row/Column size, I got following:

UserControlSon freezes, so I can't resize UserControlSon, I can't move GridSplitter with cursor.

I have all Grid.Row Height set as Star type (for proportional scaling) dynamically. For example (30* and 70* so I get 30% and 70% parts of window).

Please, help!

How Can I solve this?

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <GridSplitter x:Name="splitViewArea" Height="5" Grid.ColumnSpan="2" VerticalAlignment="Bottom" HorizontalAlignment="Stretch" Grid.Row="0" Grid.Column="0" />

    <local:SomeControl x:Name="UserControlSon"/>
</Grid>