Botón de acción flotante en Xamarin.Forms

Antes de que saliera la biblioteca de apoyo oficial, volví a portar la FAB.

Ahora hay un ejemplo de Xamarin.Forms en mi repo de GitHub que puedes usar: https://github.com/jamesmontemagno/FloatingActionButton-for-Xamarin.Android

Creación de un control personalizado Para que las propiedades de FAB sean vinculables en Xamarin.Forms, necesitamos un control personalizado con propiedades vinculables.

 public class FloatingActionButtonView : View { public static readonly BindableProperty ImageNameProperty = BindableProperty.Create<FloatingActionButtonView,string>( p => p.ImageName, string.Empty); public string ImageName { get { return (string)GetValue (ImageNameProperty); } set { SetValue (ImageNameProperty, value); } } public static readonly BindableProperty ColorNormalProperty = BindableProperty.Create<FloatingActionButtonView,Color>( p => p.ColorNormal, Color.White); public Color ColorNormal { get { return (Color)GetValue (ColorNormalProperty); } set { SetValue (ColorNormalProperty, value); } } public static readonly BindableProperty ColorPressedProperty = BindableProperty.Create<FloatingActionButtonView,Color>( p => p.ColorPressed, Color.White); public Color ColorPressed { get { return (Color)GetValue (ColorPressedProperty); } set { SetValue (ColorPressedProperty, value); } } public static readonly BindableProperty ColorRippleProperty = BindableProperty.Create<FloatingActionButtonView,Color>( p => p.ColorRipple, Color.White); public Color ColorRipple { get { return (Color)GetValue (ColorRippleProperty); } set { SetValue (ColorRippleProperty, value); } } ... } 

A continuación, asignaremos cada propiedad a una propiedad correspondiente en el control FAB nativo.

Adjuntar un procesador

Si queremos usar un control nativo en Xamarin.Forms, necesitamos un renderizador. Para simplificar, vamos a utilizar un ViewRenderer . Este renderizador asignará nuestro FloatingActionButtonView personalizado a un Android.Widget.FrameLayout .

 public class FloatingActionButtonViewRenderer : ViewRenderer<FloatingActionButtonView, FrameLayout> { ... private readonly Android.Content.Context context; private readonly FloatingActionButton fab; public FloatingActionButtonViewRenderer() { context = Xamarin.Forms.Forms.Context; fab = new FloatingActionButton(context); ... } protected override void OnElementChanged(ElementChangedEventArgs<FloatingActionButtonView> e) { base.OnElementChanged(e); if (e.OldElement != null || this.Element == null) return; if (e.OldElement != null) e.OldElement.PropertyChanged -= HandlePropertyChanged; if (this.Element != null) { //UpdateContent (); this.Element.PropertyChanged += HandlePropertyChanged; } Element.Show = Show; Element.Hide = Hide; SetFabImage(Element.ImageName); fab.ColorNormal = Element.ColorNormal.ToAndroid(); fab.ColorPressed = Element.ColorPressed.ToAndroid(); fab.ColorRipple = Element.ColorRipple.ToAndroid(); var frame = new FrameLayout(Forms.Context); frame.RemoveAllViews(); frame.AddView(fab); SetNativeControl (frame); } public void Show(bool animate = true) { fab.Show(animate); } public void Hide(bool animate = true) { fab.Hide(animate); } void HandlePropertyChanged (object sender, System.ComponentModel.PropertyChangedEventArgs e) { if (e.PropertyName == "Content") { Tracker.UpdateLayout (); } else if (e.PropertyName == FloatingActionButtonView.ColorNormalProperty.PropertyName) { fab.ColorNormal = Element.ColorNormal.ToAndroid(); } else if (e.PropertyName == FloatingActionButtonView.ColorPressedProperty.PropertyName) { fab.ColorPressed = Element.ColorPressed.ToAndroid(); } else if (e.PropertyName == FloatingActionButtonView.ColorRippleProperty.PropertyName) { fab.ColorRipple = Element.ColorRipple.ToAndroid(); } ... } void SetFabImage(string imageName) { if(!string.IsNullOrWhiteSpace(imageName)) { try { var drawableNameWithoutExtension = Path.GetFileNameWithoutExtension(imageName); var resources = context.Resources; var imageResourceName = resources.GetIdentifier(drawableNameWithoutExtension, "drawable", context.PackageName); fab.SetImageBitmap(Android.Graphics.BitmapFactory.DecodeResource(context.Resources, imageResourceName)); } catch(Exception ex) { throw new FileNotFoundException("There was no Android Drawable by that name.", ex); } } } } 

Juntar todos juntos

¡DE ACUERDO! Hemos creado el control personalizado y lo hemos asignado a un renderizador. El último paso es establecer el control en nuestra opinión.

 public class MainPage : ContentPage { public MainPage() { var fab = new FloatingActionButtonView() { ImageName = "ic_add.png", ColorNormal = Color.FromHex("ff3498db"), ColorPressed = Color.Black, ColorRipple = Color.FromHex("ff3498db") }; // Main page layout var pageLayout = new StackLayout { Children = { new Label { VerticalOptions = LayoutOptions.CenterAndExpand, XAlign = TextAlignment.Center, Text = "Welcome to Xamarin Forms!" } }}; var absolute = new AbsoluteLayout() { VerticalOptions = LayoutOptions.FillAndExpand, HorizontalOptions = LayoutOptions.FillAndExpand }; // Position the pageLayout to fill the entire screen. // Manage positioning of child elements on the page by editing the pageLayout. AbsoluteLayout.SetLayoutFlags(pageLayout, AbsoluteLayoutFlags.All); AbsoluteLayout.SetLayoutBounds(pageLayout, new Rectangle(0f, 0f, 1f, 1f)); absolute.Children.Add(pageLayout); // Overlay the FAB in the bottom-right corner AbsoluteLayout.SetLayoutFlags(fab, AbsoluteLayoutFlags.PositionProportional); AbsoluteLayout.SetLayoutBounds(fab, new Rectangle(1f, 1f, AbsoluteLayout.AutoSize, AbsoluteLayout.AutoSize)); absolute.Children.Add(fab); Content = absolute; } } 

Código completo en Github: Botón de acción flotante Xamarin.Forms