How to collapse individual nested grids/stackpanels inside a grid?

Question

Hi, I have been trying to collapse 1 of 2 grids inside a grid, but the parent grid always collapses these 2 children grids.

<Grid x:Name="ParentGrid">  
 <Grid x:Name="ChildGrid1">  
 </Grid>  
  
 <Grid x:Name="ChildGrid2">  
 </Grid>  
  
</Grid>  
  
  
...  
this.ChildGrid1.Visibility = Visibility.collapsed;  

Answer 1

I think I found out why the ParentGrid collapsed all is that I put the ParentGrid in another Grid that is in a ScrollViewer, but I put the ScrollViewer in another Grid with RowDefinition.Height="Auto". So If I do not use the ScrollViewer, I can make the ChildGrid1 collapses. And If I set the RowDefinition.Height from "Auto" to "*", I can use the ScrollViewer to scroll the content and also make the childGrid1 collapses.

<Grid x:Name="ParentGrid">  
	<Grid.RowDefinitions>  
		<RowDefinition Height="Auto"/>  
		<RowDefinition Height="*"/>  
	</Grid.RowDefinitions>  
	  
	<Grid Grid.Row="0" x:Name="ChildGrid1">  
	</Grid>  
	  
	<Grid Grid.Row="1" x:Name="ChildGrid2">  
	</Grid>  
	  
</Grid>  
	  
	  
...  
this.ChildGrid1.Visibility = Visibility.collapsed;  
	  
	  
<Grid>  
	<Grid.RowDefinitions>  
		<RowDefinition Height="Auto"/>  
		<!--RowDefinition Height="Auto"-->  
		<RowDefinition Height="*"/>   
	</Grid.RowDefinitions>  
	  
	<ScrollViewer Grid.Row="1">  
		<Grid>  
			<Grid.RowDefinitions>  
				<RowDefinition Height="Auto"/>  
				<RowDefinition Height="Auto"/>  
			</Grid.RowDefinitions>  
		  
			<!--An User Control that has the ParentGrid (Grid)-->  
			<userControls:MyUserControl Grid.Row="0"/>  
			<userControls:MyUserControl2 Grid.Row="1"/>  
		</Grid>  
	</ScrollViewer>  
</Grid>