[Problem/Bug]: Memory leak? WebView2 and parent window not released after close

[cuiliang]

What happened?

Using the smaple application: https://github.com/MicrosoftEdge/WebView2Samples/tree/main/SampleApps/WebView2WpfBrowser

1. start the application
2. New window mutliple times
   
3. Close the windows, and leave one to keep application running.
4. Use dotmemory, attach to the process, and take snapshots.
5. WebView2 and MainWindow objects never got GC collected.

Importance

Moderate. My app's user experience is affected, but still usable.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

120.0.2210.121

SDK Version

1.0.2210.55

Framework

WPF

Operating System

Windows 11

OS Version

No response

Repro steps

See issue description.

Repros in Edge Browser

No

Regression

No, this never worked

Last working version (if regression)

No response

AB#48526819

[cuiliang]

This is another test, after window closed more than 10 minutes and Force GC in dotMemory, objects still not GC collected.

[vbryh-msft]

@cuiliang thank you for reporting the issue. I have created work item to take time to look into it.

[cuiliang]

@vbryh-msft Besides, if the HostObject used in AddHostObjectToScript() hode a reference of host window, there will be another
referenct path live after window closed.

[monica-ch]

@cuiliang We've fixed the issue in Edge canary 126.0.2536.0+. Please test and let us if WV2 objects are still leaking.

Also, there is a small issue in WebView2WpfBrowser where the code isn't calling webView.Dispose() upon Close WebView. We'll soon push that sample app fix to our public repo but please call WV2 dispose for testing.

[TWhidden]

Can we assume this has not been fixed as of yet? Have the same issue on 128.0.2739.42.

The instance count continues to grow every time our WPF control creates a WebView2. If we hook into Unload, and call Dispose(), it does release everything, however we can't depend on that because Unload would be called even if it's in a TabControl and you change tabs. In our application, new controls are created and removed regularly, so these are stacking up.

[champnic]

Closing this issue as fixed, as it was specific to our sample app. @TWhidden The key is you need to find the right place in your app where you no longer need a specific WebView2 control and ensure Dispose() is getting called. Or re-use existing controls. If you are still running into an issue, feel free to ask a question in our Discussions, or open a bug if you believe there is an issue on the WebView2 side.