Added memory leak gallery (#5795)

* Added memory leak gallery

* fixes getting content

diff --git a/Xamarin.Forms.Controls/CoreGallery.cs b/Xamarin.Forms.Controls/CoreGallery.cs
index ab7785c..942f9d4 100644 (file)
--- a/Xamarin.Forms.Controls/CoreGallery.cs
+++ b/Xamarin.Forms.Controls/CoreGallery.cs
@@ -282,6 +282,7 @@ namespace Xamarin.Forms.Controls
                }
 
                List<GalleryPageFactory> _pages = new List<GalleryPageFactory> {
+                               new GalleryPageFactory(() => new MemoryLeakGallery(), "Memory Leak"),
                                new GalleryPageFactory(() => new Issues.A11yTabIndex(), "Accessibility TabIndex"),
                                new GalleryPageFactory(() => new FontImageSourceGallery(), "Font ImageSource"),
                                new GalleryPageFactory(() => new CollectionViewGallery(), "CollectionView Gallery"),

diff --git a/Xamarin.Forms.Controls/GalleryPages/MemoryLeakGallery.cs b/Xamarin.Forms.Controls/GalleryPages/MemoryLeakGallery.cs
new file mode 100644 (file)
index 0000000..0cd7fc0
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/MemoryLeakGallery.cs
@@ -0,0 +1,114 @@
+using System;
+using System.Collections.Generic;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls
+{
+       [Preserve(AllMembers = true)]
+       public class MemoryLeakGallery : MasterDetailPage
+       {
+               List<WeakReference> wref = new List<WeakReference>();
+
+               Label result;
+
+               Button checkResult;
+
+               Button MakeButton(string text, Func<View> getContent)
+               {
+                       return new Button
+                       {
+                               Text = text,
+                               Command = new Command(async () =>
+                               {
+                                       View content = getContent();
+                                       await Detail.Navigation.PushAsync(new ContentPage { Content = content });
+                                       Detail.Navigation.RemovePage(Detail.Navigation.NavigationStack[0]);
+
+                                       await Detail.Navigation.PushAsync(new ContentPage());
+                                       var pageToRemove = Detail.Navigation.NavigationStack[0];
+                                       Detail.Navigation.RemovePage(pageToRemove);
+
+                                       wref.Add(new WeakReference(pageToRemove));
+                                       wref.Add(new WeakReference(content));
+                                       result.Text = string.Empty;
+                               })
+                       };
+               }
+
+               public MemoryLeakGallery()
+               {
+                       result = new Label
+                       {
+                               FontSize = 16,
+                               Text = string.Empty
+                       };
+
+                       checkResult = new Button
+                       {
+                               Text = "Check Result",
+                               BackgroundColor = Color.DarkRed,
+                               TextColor = Color.White,
+                               Command = new Command(() =>
+                               {
+                                       GC.Collect();
+                                       GC.WaitForPendingFinalizers();
+                                       GC.Collect();
+
+                                       if (wref.Count < 4)
+                                               return;
+
+                                       if (wref[0].IsAlive || wref[1].IsAlive)
+                                       {
+                                               Title = result.Text = "Failed";
+                                               result.TextColor = Color.Red;
+                                       }
+                                       else
+                                       {
+                                               Title = result.Text = "Success";
+                                               result.TextColor = Color.DarkGreen;
+                                       }
+                                       wref.Clear();
+                               })
+                       };
+
+                       Master = new ContentPage
+                       {
+                               Title = "menu",
+                               Content = new ScrollView
+                               {
+                                       Content = new StackLayout
+                                       {
+                                               Children =
+                                               {
+                                                       checkResult,
+                                                       new Label { Text = "Click on button twice, then check result" },
+                                                       result,
+                                                       MakeButton("Empty page", () => null),
+                                                       MakeButton(nameof(ActivityIndicator), () => new ActivityIndicator { IsRunning = true }),
+                                                       MakeButton(nameof(BoxView), () => new BoxView { Color = Color.Azure }),
+                                                       MakeButton(nameof(Button), () => new Button { Text = "Button" }),
+                                                       MakeButton(nameof(DatePicker), () => new DatePicker ()),
+                                                       MakeButton(nameof(Label), () => new Label { Text = "Label" }),
+                                                       MakeButton(nameof(Entry), () => new Entry { Text = "Entry" }),
+                                                       MakeButton(nameof(Editor), () => new Editor { Text = "Editor" }),
+                                                       MakeButton(nameof(Image), () => new Image { BackgroundColor = Color.Azure, HeightRequest = 50 }),
+                                                       MakeButton(nameof(ImageButton), () => new ImageButton { BackgroundColor = Color.Azure, HeightRequest = 50 }),
+                                                       MakeButton(nameof(WebView), () => new WebView { BackgroundColor = Color.Azure, HeightRequest = 50 }),
+                                                       MakeButton(nameof(ProgressBar), () => new ProgressBar { BackgroundColor = Color.Azure, Progress = 0.5 }),
+                                                       MakeButton(nameof(Picker), () => new Picker { BackgroundColor = Color.Azure, HeightRequest = 50 }),
+                                                       MakeButton(nameof(OpenGLView), () => new OpenGLView ()),
+                                                       MakeButton(nameof(SearchBar), () => new SearchBar ()),
+                                                       MakeButton(nameof(Slider), () => new Slider ()),
+                                                       MakeButton(nameof(Stepper), () => new Stepper ()),
+                                                       MakeButton(nameof(Switch), () => new Switch ()),
+                                                       MakeButton(nameof(TimePicker), () => new TimePicker ()),
+                                                       MakeButton(nameof(TableView), () => new TableView ()),
+                                               }
+                                       }
+                               }
+                       };
+
+                       Detail = new NavigationPage(new ContentPage());
+               }
+       }
+}
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