The page in WinUI3 cannot be filled automatically in TabViewItem

Question

OrderV.xaml wrong effect desired effect

 Frame frame = new Frame();
 frame.Navigate(typeof(OrderV));

 TabViewItem tabViewItem = new()
 {
     Header = "Order",
     Content = frame
 };
 
tabViewItem.IsSelected = true;
TabViewControl.TabItems.Add(tabViewItem);

I've tried using Frame alone and it's fine, but I want Page to work in a TabViewItem

<Frame Name="MenuFrame" />

MenuFrame.Navigate(typeof(OrderV));

Answer 1

You need to add VerticalAlignment="Stretch" to your TabView control. Here is a minimal sample from your code.

MainWindow.xaml

<Grid RowDefinitions="Auto,*">
    <Button
        Grid.Row="0"
        Click="Button_Click"
        Content="Start" />
    <TabView
        x:Name="TabViewControl"
        VerticalAlignment="Stretch"
        Grid.Row="1" />
</Grid>

MainWindow.xaml.cs

public sealed partial class MainWindow : Window
{
    public MainWindow()
    {
        this.InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Frame frame = new();
        frame.Navigate(typeof(OrderV));

        TabViewItem tabViewItem = new()
        {
            Header = "Order",
            Content = frame
        };

        tabViewItem.IsSelected = true;
        TabViewControl.TabItems.Add(tabViewItem);
    }
}