Expanders in distinct columns in one row. Expand to the full row - wpf

Question

I have two expanders in one grid row but in distinct columns. How can I expand each of it to the full row but not on column only.
<Grid x:Name="mainGrid">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="90"/>
<ColumnDefinition Width="90"/>
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition MinHeight="40" />
<RowDefinition MinHeight="40" />
</Grid.RowDefinitions>
<Controls:Expander Grid.Row="0" Grid.Column="0" x:Name="expander2" Header="Header1"
MinHeight="33" Padding="3">
<TextBlock Text="SomeText1" />
</Controls:Expander>
<Controls:Expander Grid.Row="0" Grid.Column="1" x:Name="expander1" Header="Header2"
MinHeight="33" Padding="3">
<TextBlock Text="SomeText2" />
</Controls:Expander>
</Grid>
expander1 and expander2 should expand to the whole row 0.

Answer 1

Introduce the triggers for Expanders that check their IsExpanded property and set their Grid.RowSpan as 2.
<Style TargetType="{x:Type Expander}">
<Style.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter Property="Grid.RowSpan" Value="2" />
</Trigger>
</Style.Triggers>
</Style>
For silverlight
<Style TargetType="{x:Type Expander}">
<Setter Property="Grid.RowSpan"
Value="{Binding IsExpanded,
RelativeSource={RelativeSource
Self},
Converter={StaticResource
local:ExpansionToRowSpanConverter}}"
</Style>
Code behind ... (this is just for illustration)
ExpansionToRowSpanConverter.Convert(....)
{
return (bool)value ? 2 : 1;
}
Does this work for you?