[Android] fix removed NativeSizeChanged (#4395)

Xamarin.Forms.Controls/GalleryPages/ImageGallery.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -8,16 +9,16 @@ namespace Xamarin.Forms.Controls
 {
 	public class ImageGallery : ContentPage
 	{
-		public ImageGallery ()
+		public ImageGallery()
 		{
 
-			Padding = new Thickness (20);
+			Padding = new Thickness(20);
 
-			var normal = new Image { Source = ImageSource.FromFile ("cover1.jpg") };
-			var disabled = new Image { Source = ImageSource.FromFile ("cover1.jpg") };
-			var rotate = new Image { Source = ImageSource.FromFile ("cover1.jpg") };
-			var transparent = new Image { Source = ImageSource.FromFile ("cover1.jpg") };
-			var embedded = new Image { Source = ImageSource.FromResource ("Xamarin.Forms.Controls.ControlGalleryPages.crimson.jpg", typeof (ImageGallery)) };
+			var normal = new Image { Source = ImageSource.FromFile("cover1.jpg") };
+			var disabled = new Image { Source = ImageSource.FromFile("cover1.jpg") };
+			var rotate = new Image { Source = ImageSource.FromFile("cover1.jpg") };
+			var transparent = new Image { Source = ImageSource.FromFile("cover1.jpg") };
+			var embedded = new Image { Source = ImageSource.FromResource("Xamarin.Forms.Controls.GalleryPages.crimson.jpg", typeof(ImageGallery).GetTypeInfo().Assembly) };
 
 			// let the stack shrink the images
 			normal.MinimumHeightRequest = normal.MinimumHeightRequest = 10;
@@ -27,45 +28,63 @@ namespace Xamarin.Forms.Controls
 			embedded.MinimumHeightRequest = 10;
 
 			disabled.IsEnabled = false;
-			rotate.GestureRecognizers.Add (new TapGestureRecognizer { Command = new Command (o => rotate.RelRotateTo (180))});
+			rotate.GestureRecognizers.Add(new TapGestureRecognizer { Command = new Command(o => rotate.RelRotateTo(180)) });
 			transparent.Opacity = .5;
 
-			Content = new StackLayout {
-				Orientation = StackOrientation.Horizontal,
-				Children = {
-					new StackLayout {
-						//MinimumWidthRequest = 20,
-						HorizontalOptions = LayoutOptions.FillAndExpand,
-						Children = {
-							normal,
-							disabled,
-							transparent,
-							rotate,
-							embedded,
-							new StackLayout {
-								HeightRequest = 30,
-								Orientation = StackOrientation.Horizontal,
-								Children = {
+			Content =
+				new ScrollView()
+				{
+					Content = new StackLayout
+					{
+						Orientation = StackOrientation.Horizontal,
+						Children =
+						{
+							new StackLayout
+							{
+								//MinimumWidthRequest = 20,
+								HorizontalOptions = LayoutOptions.FillAndExpand,
+								Children =
+								{
+									new Label(){ Text = "Normal"},
+									normal,
+									new Label(){ Text = "Disabled"},
+									disabled,
+									new Label(){ Text = "Transparent"},
+									transparent,
+									new Label(){ Text = "Rotate"},
+									rotate,
+									new Label(){ Text = "Embedded"},
+									embedded,
+									new Label(){ Text = "Horizontal"},
+									new StackLayout
+									{
+										HeightRequest = 30,
+										Orientation = StackOrientation.Horizontal,
+										Children =
+										{
+											new Image {Source = "cover1.jpg"},
+											new Image {Source = "cover1.jpg"},
+											new Image {Source = "cover1.jpg"},
+											new Image {Source = "cover1.jpg"}
+										}
+									}
+								}
+							},
+							new StackLayout
+							{
+								WidthRequest = 30,
+								Children =
+								{
 									new Image {Source = "cover1.jpg"},
 									new Image {Source = "cover1.jpg"},
 									new Image {Source = "cover1.jpg"},
 									new Image {Source = "cover1.jpg"}
 								}
 							}
-						}
-					},
-					new StackLayout {
-						WidthRequest = 30,
-						Children = {
-							new Image {Source = "cover1.jpg"},
-							new Image {Source = "cover1.jpg"},
-							new Image {Source = "cover1.jpg"},
-							new Image {Source = "cover1.jpg"}
+
 						}
 					}
-
-				}
-			};
+				};
 		}
 	}
 }

Xamarin.Forms.Platform.Android/Extensions/ImageViewExtensions.cs

@@ -80,6 +80,7 @@ namespace Xamarin.Forms.Platform.Android
 
 			bitmap?.Dispose();
 			imageController?.SetIsLoading(false);
+			imageController?.NativeSizeChanged();
 		}
 	}
 }