Xamarin Listview cannot scroll to bottm - xaml

Question

I modify the sample https://learn.microsoft.com/zh-tw/samples/xamarin/xamarin-forms-samples/userinterface-xaminals/ ,
replace the collectionview with listview . after replacing I found the listview cannot scroll to bottom (there are total 17 items , but only show 6 items)
This error only happen on Android,but it works well on IOS.
How to solve this problem?
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:controls="clr-namespace:Xaminals.Controls"
xmlns:data="clr-namespace:Xaminals.Data"
x:Class="Xaminals.Views.MonkeysPage"
Title="Monkeys">
<RelativeLayout
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand">
<StackLayout Orientation="Vertical"
VerticalOptions="FillAndExpand"
Padding="10">
<ListView ItemsSource="{x:Static data:MonkeyData.Monkeys}"
x:Name="CollectionView1"
RowHeight="100">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Grid VerticalOptions="CenterAndExpand" Padding = "20, 0" >
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Image
Grid.RowSpan="2"
Aspect="AspectFill"
HeightRequest="60"
Source="{Binding ImageUrl}"
WidthRequest="60" />
<Label
Grid.Row="0"
Grid.Column="1"
FontAttributes="Bold"
Text="{Binding Name}" />
<Label
Grid.Row="1"
Grid.Column="1"
FontAttributes="Italic"
Text="{Binding Price}"
VerticalOptions="End" />
<Image Grid.Row="2" Grid.Column="0" Source="bear.png" HeightRequest="25" WidthRequest="25">
<Image.GestureRecognizers>
<TapGestureRecognizer
NumberOfTapsRequired="1" />
</Image.GestureRecognizers>
</Image>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<ActivityIndicator x:Name="activityIndicator" Color="Red" VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=0.33}" RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height,Factor=0.33}" />
</RelativeLayout>
</ContentPage>

Answer 1

The solution is change the RelativeLayout to Stacklayout:
<StackLayout
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand">
<StackLayout Orientation="Vertical"
VerticalOptions="FillAndExpand"
Padding="10">
<ListView ItemsSource="{x:Static data:MonkeyData.Monkeys}"
x:Name="CollectionView1"
RowHeight="100">
.....
</ListView>
</StackLayout>
</StackLayout>
If you want to use RelativeLayout, you need to use XConstraint, YConstraint,WidthConstraint,HeightConstraint to layout the child view instead of VerticalOptions="FillAndExpand", HorizontalOptions="FillAndExpand".