Create a BaseClass for ContentPage

Question

In my MAUI project, I have a lot of views as ContentPage that share some common functions. So, I want to create a base class with those functions to use across the ContentPages.

Every page has different viewmodels, UI and all the usual components (like DisplayAlert). Based on another post and this one, I wrote my base class

public abstract class BaseContentPageClass<T> : ContentPage 
                      where T : BaseViewModel
{
    public BaseContentPageClass(T viewModel, string pageTitle)
    {
        BindingContext = ViewModel = viewModel;
        Title = pageTitle;
    }

    protected T ViewModel { get; }
}

Then, I like to have a base class for the ContentView that has to display advertisements, for example. So, I created another class BaseAdvClass based on the base class

public partial class BaseAdvClass<T> : 
       BaseContentPageClass<T> where T : BaseViewModel
{
    #region Variables
    public bool ShouldSetEvents { get; set; } = true;
    public long Points { get; set; } = 100;

    private readonly UserSettings settings;
    #endregion

    public BaseAdvClass(T viewModel, string pageTitle, UserSettings settings) 
           : base(viewModel, pageTitle)
    {
        this.settings = settings;

        InitializeComponent();
    }
}

Then, I created a new ContentPage named ProfilePage and this is the XAML and the code behind:

<local:BaseAdvClass xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         xmlns:lang="clr-namespace:MyProject"
         x:Class="MyProject.Views.ProfilePage"
         xmlns:local="clr-namespace:MyProject.Views">

public class ProfilePage : BaseAdvClass<ProfilePageViewModel>
{
    ProfilePageViewModel vm;

    private bool _shouldSetEvents = true;

    public ProfilePage(ProfilePageViewModel model, UserSettings settings) 
           : base(model, "", settings)
    {
    }

    // ...
}

At this point the build raises a lot of errors:

• Using the generic type 'BaseAdvClass' requires 1 type arguments (LanguageInUse)
• in the code behind for the base, it requires the class as partial but when I add partial I get another error

• in this page DisplayAlert doesn't exist in the current context
• in the BaseAdvClass, InitializeComponent doesn't exist in the current context
• if I add in the constructor of BaseContentPageClass the InitializeComponent I get the same error (doesn't exist in the current context)