WPF control is not reclaimed on NET9 by GC #9467
Description
Description
GC does not reclaim control memory in following scenario. The control is placed in the visual tree and then removed from it. Conditions must be met:
- PresentationTraceSources.Refresh() call
- there is a subscriber to the Unloaded event of control
Reproduction Steps
Run test TestLeak in project targeting net9.0-windows. NUnit version is 3.12.0.
using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Threading;
using NUnit.Framework;
namespace Sample {
[TestFixture]
public class MemoryTests {
[Test]
public void TestLeak() {
PresentationTraceSources.Refresh();
var window = new Window();
var wr = AddAndRemoveImage(window);
GC.Collect();
GC.WaitForPendingFinalizers();
Assert.IsFalse(wr.IsAlive);
}
static WeakReference AddAndRemoveImage(Window window) {
var img = new Image();
var wr = new WeakReference(img);
var holder = new ImageHolder(img);
window.Content = img;
window.Show();
DoEvents();
window.Content = null;
DoEvents();
return wr;
}
static void DoEvents() {
var frame = new DispatcherFrame();
Dispatcher.CurrentDispatcher.InvokeAsync(() => frame.Continue = false, DispatcherPriority.Background);
Dispatcher.PushFrame(frame);
}
class ImageHolder {
readonly Image image;
public ImageHolder(Image image) {
this.image = image;
this.image.Loaded += OnLoaded;
this.image.Unloaded += OnUnloaded;
}
void OnLoaded(object sender, RoutedEventArgs e) {
Debug.WriteLine("OnLoaded");
}
void OnUnloaded(object sender, RoutedEventArgs e) {
Debug.WriteLine("OnUnloaded");
}
}
}
}Expected behavior
The test passes.
Actual behavior
The test fails.
Regression?
This works in net8.0 and net462.
Known Workarounds
No response
Configuration
.NET: 9.0.0-preview.6.24327.6
OS: Windows 10, Version 22H2 (OS Build 19045.4651)
Architecture: x64
Other information
No response