Implementing a ContentPresenter with C# Markup

[rlebowitz]

I've created a ControlTemplate based on the RadioButton control in Maui. I'm interested in using a ContentPresenter to be able to reuse the control with several different button appearances. Unfortunately, there don't seem to be any examples of how to do this. I did find an example of an custom Accordion control where the author included a BindableProperty of type View as a way bind content to a custom control, though I've been unable to get this approach to work with my own control.

Below are some code snippets of what I've experimented with thus far. I figured out that I had to add the Content to the grid in my control within the propertyChanged: method of my BindableProperty and not in the constructor.

Any advice would be appreciated!

public partial class RadioButtonTemplate : RadioButton where T : ObservableObject {}

public static readonly BindableProperty ContentPresenterProperty = BindableProperty.Create(nameof(ContentPresenter),
    typeof(View), typeof(RadioButtonTemplate<T>), default(View),
    propertyChanged: (bindable, oldValue, newValue) =>
    {
        if (bindable is RadioButtonTemplate<T> instance)
        {
            instance.ContentPresenter = (View)newValue;
            instance.OuterGrid.Clear();
            instance.OuterGrid.Children.Add(instance.InnerGrid.Row(Row.Ellipse).Column(Column.Zero));
            instance.OuterGrid.Children.Add(instance.ContentPresenter.Row(Row.ContentPresenter).Column(Column.Zero));
        }
    });

public View ContentPresenter
{
    get => (View)GetValue(ContentPresenterProperty);
    set => SetValue(ContentPresenterProperty, value);
}

[JoeVoo]

if understanding you right, you need this to create a control where you can add views as Contexts:

   [ContentProperty("Contents")]
   public partial class ColPageButtonLine : ContentView
   {
       private StackLayout ContentStack { get; } = [];
       public StackLayout Contents => (StackLayout)ContentStack.Children;

       public new ICollectionBaseViewModel BindingContext
       {
           get => (ICollectionBaseViewModel)base.BindingContext;
           set => base.BindingContext = value;
       }

       public ColPageButtonLine()
       {
           // Content Presenter for additional buttons
           Contents.Spacing = 5;
           Contents.Orientation = StackOrientation.Horizontal;
           Contents.VerticalOptions = LayoutOptions.End;
           ContentPresenter contentPresenter = new()
           {
               Content = Contents.CenterHorizontal(),
           };