/// <summary> /// Specify a method to be run before an existing property mapping. /// </summary> /// <typeparam name="TVirtualView">The cross-platform type.</typeparam> /// <typeparam name="TViewHandler">The handler type.</typeparam> /// <param name="propertyMapper">The property mapper in which to change the mapping.</param> /// <param name="key">The name of the property.</param> /// <param name="method">The method to call before the existing mapping begins.</param> public static void PrependToMapping <TVirtualView, TViewHandler>(this IPropertyMapper <TVirtualView, TViewHandler> propertyMapper, string key, Action <TViewHandler, TVirtualView> method) where TVirtualView : IElement where TViewHandler : IElementHandler { propertyMapper.ModifyMapping(key, (handler, view, action) => { method(handler, view); action?.Invoke(handler, view); }); }