Can the BindRequired attribute be used in MvvmCross, and if so, how

However, if you are integrating ASP.NET Core services or APIs into an MvvmCross application, you might use `[BindRequired]` in the context of those services. For example, if your MvvmCross app consumes a REST API built with ASP.NET Core, the API could use `[BindRequired]` to enforce model binding rules on incoming requests.

In MvvmCross itself, you would typically handle data binding and validation through other mechanisms. MvvmCross provides its own set of tools for binding data between views and view models, such as the `MvxBind` attribute for specifying bindings in XAML or Android layouts[7]. For validation, you might use custom logic within your view models or leverage third-party validation libraries.

To achieve similar functionality to `[BindRequired]` in MvvmCross, you could implement custom validation logic within your view models. This might involve checking if a property has been set or if it meets certain criteria before allowing the view model to proceed with its actions.

Here's a basic example of how you might implement a required property check in a view model:

csharp
public class MyViewModel : MvxViewModel
{
    private int _age;

    public int Age
    {
        get => _age;
        set => SetProperty(ref _age, value);
    }

    public void Proceed()
    {
        if (Age == default(int))
        {
            // Handle the case where Age is not set
            Mvx.IoCProvider.Resolve().Navigate();
        }
        else
        {
            // Proceed with the action
        }
    }
}

In this example, the `Proceed` method checks if `Age` has been set before proceeding. If `Age` is still at its default value (indicating it hasn't been set), it navigates to an error view.

For more complex scenarios, you might consider using a validation library or implementing a custom validation system within your MvvmCross application.