Xamarin.Forms: Chainable and Strongly-Typed SetBinding() Extension

BindableObjectExtensions.cs

public static class BindableObjectExtensions
{
	// chainable, with a string for property
	// usage : new Button().WithBinding(Button.CommandProperty, "SomeCommand"),
	public static T WithBinding<T>(this T obj, 
		BindableProperty bindableProperty, 
		string path, 
		BindingMode mode = BindingMode.Default, 
		IValueConverter converter = null, 
		object converterParameter = null, 
		string stringFormat = null
	)
		where T:BindableObject
	{
		obj.SetBinding (bindableProperty, new Binding (path, mode, converter, converterParameter, stringFormat));
		return obj;
	}

	// chainable, with a lambda for property
	// usage : new Button().WithBinding(Button.CommandProperty, (MyViewModel vm) => vm.SomeCommand),
	public static TOUT WithBinding<TOUT, TVM, TO>(this TOUT obj, 
		BindableProperty bindableProperty, 
		Expression<Func<TVM, TO>> sourceProperty, 
		BindingMode mode = BindingMode.Default, 
		IValueConverter converter = null, 
		object converterParameter = null, 
		string stringFormat = null
	)
		where TOUT:BindableObject
		where TVM:INotifyPropertyChanged
	{
		//var name = ((MemberExpression)sourceProperty.Body).Member.Name;
		// hack for supporting VMs in VMs
		var body = sourceProperty.Body.ToString ();
		string name;
		if (body.Contains ("."))
			name = body.Substring (body.IndexOf (".", StringComparison.Ordinal) + 1);
		else
			name = body;

		obj.SetBinding (bindableProperty, new Binding (name, mode, converter, converterParameter, stringFormat));
		return obj;
	}
}