Property MultiBinding

You can easily use multibinding with FmgLib.MauiMarkup. You can add as many BindingBases as you want with the e.Bindings(...) method.

Example usage is as follows:

public partial class MainPage : ContentPage, IFmgLibHotReload
{
    private readonly MainPageViewModel viewModel;
    public MainPage()
    {
        viewModel = new MainPageViewModel();
        this.InitializeHotReload();
    }

    public void Build()
    {
        this
        .BindingContext(viewModel)
        .Content(
            new VerticalStackLayout()
            .Spacing(20)
            .Children(
                new CheckBox()
                .IsChecked(e => 
                    e.Bindings(
                        new Binding().Path("Employee.IsOver16"),
                        new Binding().Path("Employee.HasPassedTest"),
                        new Binding().Path("Employee.IsSuspended").Converter(new InverterConverter())
                    )
                    .Converter(new AllTrueMultiConverter())
                    .FallbackValue("Is Error.")
                    .TargetNullValue("Is Null.")
                ),

                new Label()
                .Text(e => 
                    e.Bindings(
                        new Binding().Path("Employee.Id"),
                        new Binding().Path("Employee.Name"),
                        new Binding().Path("Employee.IsSuspended")
                    )
                    .StringFormat("{0} : {1} : {2}")
                    .FallbackValue("Is Error.")
                    .TargetNullValue("Is Null.")
                )
            )
        );
    }
}