Free space using FillAndExpand - xaml

Question

Im' working on XAML view and I want to create simple view with left side bar and the content with Grid and inside grid I have some buttons, that I want to achieve is to fill all form
Code:
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:App.ViewModels"
mc:Ignorable="d"
x:Class="App.Views.UserSelectionPage">
<ContentPage.Content>
<StackLayout Orientation="Horizontal" HorizontalOptions="FillAndExpand">
<StackLayout Orientation="Vertical">
<StackLayout Orientation="Vertical" BackgroundColor="#093145" HorizontalOptions="Start" VerticalOptions="FillAndExpand" >
<Label Text="AppName"
Grid.Row="0"
Grid.Column="1"
HorizontalOptions="Center"
VerticalOptions="Center"
FontSize="Header"
TextColor="White"
Margin="15,0,10,15" />
</StackLayout>
<StackLayout Orientation="Vertical" VerticalOptions="End" BackgroundColor="#093145">
<Image Source="Assets/LargeTitle.scale-100.png"
Grid.Row="0"
Grid.Column="0"
HorizontalOptions="Center"
WidthRequest="90"
HeightRequest="90"
Margin="15,0,10,15"
VerticalOptions="Center"/>
</StackLayout>
</StackLayout>
<Grid BackgroundColor="AliceBlue">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<!--<BoxView Color="#505CA9" Grid.Row="0" Grid.ColumnSpan="3" />-->
<Button Text="Use username instead"
Command="{Binding ToggleNewUserCommand}"
Grid.Row="0"
Grid.Column="2"
VerticalOptions="Center"
HorizontalOptions="End"
BackgroundColor="Transparent"
FontSize="Title"
TextColor="White"
Margin="15,0,10,15"/>
<Button x:Name="userOne"
d:Text="GQ"
Text="{Binding UserSelectionList[0].Abbreviation}"
Command="{Binding ButtonSelectedCommand}"
CommandParameter="{x:Reference userOne}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Margin="0,40,0,40"
Grid.Row="1"
Grid.Column="0"
BackgroundColor="{Binding UserSelectionList[0].BackgroundColor}"
d:BackgroundColor="#093145"/>
<Button x:Name="userTwo"
d:Text="LR"
Text="{Binding UserSelectionList[1].Abbreviation}"
Command="{Binding ButtonSelectedCommand}"
CommandParameter="{x:Reference userTwo}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Margin="0,40,0,40"
Grid.Row="1"
Grid.Column="1"
BackgroundColor="{Binding UserSelectionList[1].BackgroundColor}"
d:BackgroundColor="#107896" />
<Button x:Name="userThree"
d:Text="AR"
Text="{Binding UserSelectionList[2].Abbreviation}"
Command="{Binding ButtonSelectedCommand}"
CommandParameter="{x:Reference userThree}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Margin="0,40,0,40"
Grid.Row="1"
Grid.Column="2"
BackgroundColor="{Binding UserSelectionList[2].BackgroundColor}"
d:BackgroundColor="#829356" />
<Button x:Name="userFour"
d:Text="RR"
Text="{Binding UserSelectionList[3].Abbreviation}"
Command="{Binding ButtonSelectedCommand}"
CommandParameter="{x:Reference userFour}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Grid.Row="2"
Grid.Column="0"
BackgroundColor="{Binding UserSelectionList[3].BackgroundColor}"
d:BackgroundColor="#EBC944" />
<Button x:Name="userFive"
d:Text="GQ"
Text="{Binding UserSelectionList[4].Abbreviation}"
Command="{Binding ButtonSelectedCommand}"
CommandParameter="{x:Reference userFive}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Grid.Row="2"
Grid.Column="1"
BackgroundColor="{Binding UserSelectionList[4].BackgroundColor}"
d:BackgroundColor="#F26D21" />
<Button x:Name="userSix"
d:Text="GQ"
Text="{Binding UserSelectionList[5].Abbreviation}"
CommandParameter="{x:Reference userSix}"
Command="{Binding ButtonSelectedCommand}"
TextColor="White"
HorizontalOptions="Center"
VerticalOptions="Center"
BorderWidth="1"
FontSize="92"
CornerRadius="160"
HeightRequest="320"
WidthRequest="320"
Grid.Row="2"
Grid.Column="2"
BackgroundColor="{Binding UserSelectionList[5].BackgroundColor}"
d:BackgroundColor="#C02F1D" />
</Grid>
</StackLayout>
</ContentPage.Content>
Problem is for some reason it has free space inclusive if I use FillAndExpand on main StackLayout
I read about that but people just say that I missing FillAndExpand, I think problem is because I use Orientation="Horizontal" into first StackLayout, but that is the way I found to merge side bar with gridview. How can I achieve this? Regards

Answer 1

Add HorizontalOptions to the Grid itself:
<Grid HorizontalOptions="FillAndExpand" BackgroundColor="AliceBlue">