Why listview Size is not adjusting automatically?

When my listview collection is changed at runtime why its size is not updating according to the collection.
<ListView x:Name="listview"ItemsSource="{Binding NewDeviceSessionList}"SelectedItem="{Binding DeviceSession, Mode=TwoWay}">

My workaround
listView.HeightRequest = 60 * NewDeviceSessionList.Count;

is there is an any better way than this??