Alex Maitland

Thanks, I'll have a look when I get a chance 👍

> When the frame window is minimized set the browser window size to 0x0 to reduce resource usage. As per https://github.com/chromiumembedded/cef/blob/c7701b8a6168f105f2c2d6b239ce3958da3e3f13/tests/cefclient/browser/browser_window_std_win.cc#L89 Form minimise resolved in #3116

[Control.VisibleChanged](https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.control.visiblechanged?view=netcore-3.1) unfortunately isn't called when switching between tabs. This appears to be a known quirk of `WinForms`. - https://stackoverflow.com/questions/45184599/visiblechanged-dont-raise-when-not-visible - http://blog.excastle.com/2004/10/18/controlvisible-ugh/ - https://stackoverflow.com/questions/391888/how-to-get-the-real-value-of-the-visible-property I have yet to find a message/event...

Commit https://github.com/cefsharp/CefSharp/commit/77aed487c973dce798cd2d8f19c9c6b6b82c282b will now handle the `OnVisibleChanged` call when the control is manually set to `Visible = true/false;` This should simplify implementing your own tab switch logic. Would could potentially...

With https://bitbucket.org/chromiumembedded/cef/commits/241941a44a260885f6455e5618189c45ffb0ed40 merged, hopefully it will make it into the `75` release, that will allow for this to be implemented cleanly.

What version of CefSharp did you test with? > CEF sample app version 101.0.18.0 feature Did you test with the command line args for WPF as listed in the bug...

Please confirm you've tested using the following ``` cefclient.exe --multi-threaded-message-loop --no-sandbox --off-screen-rendering-enabled --enable-gpu ```

Based on additional feedback the CEF OSR implementation which WPF uses needs fixes to support the new PDF viewer implementation. Looks like you already raised https://github.com/chromiumembedded/cef/issues/3331 report your findings there....

There are multiple potentially related issues with the OSR implementation currently - https://bitbucket.org/chromiumembedded/cef/issues/3325/osr-mouse-wheel-events-are-not-always - https://bitbucket.org/chromiumembedded/cef/issues/3271/osr-scrolling-impossible-when-auto-scroll - https://bitbucket.org/chromiumembedded/cef/issues/2949/osr-windows-mouse-wheel-scrolling-doesnt

> Does the cef log provide any relevant information? (By default there should be a debug.log file in your bin directory) Any errors in the log? Any further issues I'd...