B4J Question B4XPage_Background not firing/how do I know when the page loses focus.

[MrKim]

B4J 10.2 win 11

Sub B4XPage_Background
    Log("B4XPage_Background-MP")
End Sub

The only time the B4XPage_Background event fires is when I close the app. I added it to one Erel's examples just to make sure I didn't mess something up.
I also tried

Private Sub B4XPage_Background
    Log("B4XPage_Background-MP")   
End Sub

I tested this with MainPage and others with the same result.
The goal is to know when the current page loses focus. I don't really care how.

 

[Erel]

See this post for more information about the events: https://www.b4x.com/android/forum/t...or-managing-multiple-pages.118901/post-744867

You can add a focus changed event with JavaObject:

    Dim jfrm As JavaObject = B4XPages.GetNativeParent(Me)
    Dim FocusEvent As Object = jfrm.CreateEvent("javafx.beans.value.ChangeListener", "Focus", Null)
    jfrm.GetFieldJO("stage").RunMethodJO("focusedProperty", Null).RunMethod("addListener", Array(FocusEvent))


Private Sub Focus_Event (MethodName As String, Args() As Object) As Object
    If MethodName = "changed" Then
        Dim focus As Boolean = Args(2)
        Log(B4XPages.GetPageId(Me) & " focus: " & focus)
    End If
    Return Null
End Sub