On macOS, closing the last window (Cmd+W or the red traffic light) was
quitting the app, which is unexpected — the native convention is that
Cmd+W closes the window while the app keeps running in the dock, and
only Cmd+Q quits.
Intercept the window CloseRequested event on macOS, prevent the close,
and hide the window instead so the app remains active. Handle the
Reopen event (fired when the user clicks the dock icon) to restore the
hidden window. Cmd+Q continues to go through applicationWillTerminate:
and exits the app normally.
Huang Xin
5190bbcafc