Setting relative height for Grid children - xamarin

Question

I'm adding 2 children to a Grid like this:
private void pInitStackLayout()
{
grid1 = new Grid()
{
};
grid2 = new Grid()
{
};
biggrid = new Grid()
{
BackgroundColor = Color.Transparent,
Margin = new Thickness(0),
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.StartAndExpand,
Orientation = StackOrientation.Vertical,
};
biggrid.Children.Add(grid1,0,0);
biggrid.Children.Add(grid2,0,1);
this.Content = biggrid;
}
The ContentPage's (which is a Navigation Page) Content is the biggrid.
I would like to make it so that grid1 takes up 80% of the available height, and grid2 takes up 20% (or the rest).
How could I achieve this?

Answer 1

It's very simple actually, just set the RowDefinitions of biggrid.
// RowDefinitions isolated
RowDefinitions = new RowDefinitionCollection
{
new RowDefinition { Height = new GridLength(8, GridUnitType.Star) },
new RowDefinition { Height = new GridLength(2, GridUnitType.Star) }
}
// RowDefinitions isolated
// Actual code
private void pInitStackLayout()
{
grid1 = new Grid()
{
};
grid2 = new Grid()
{
};
biggrid = new Grid()
{
RowDefinitions = new RowDefinitionCollection
{
new RowDefinition { Height = new GridLength(8, GridUnitType.Star) },
new RowDefinition { Height = new GridLength(2, GridUnitType.Star) }
},
BackgroundColor = Color.Transparent,
Margin = new Thickness(0),
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.StartAndExpand,
Orientation = StackOrientation.Vertical,
};
biggrid.Children.Add(grid1,0,0);
biggrid.Children.Add(grid2,0,1);
this.Content = biggrid;
}