Android Question B4XPages - handling the back key

[Patrick Clark]

how can i handle the "back" key on pages that don't have a parent. ie. they have been displayed with

B4XPages.ShowPageAndRemovePreviousPages

On a page with a parent I can use

Private Sub B4XPage_CloseRequest As ResumableSub
     Return False
End Sub

But if the page that is currently displayed is the only page in the stack the app crashes when i press the back key

 

[mangojack]

Do you have this line in the 'Main' module ... ?

Sub Activity_KeyPress (KeyCode As Int) As Boolean    
    Return B4XPages.Delegate.Activity_KeyPress(KeyCode)    
End Sub

If so remove it .

[B4X] B4XPages - how to handle Activity_KeyPress

How i use Activity_KeyPress in B4XPages? I see in the main activity is the following: Sub Activity_KeyPress (KeyCode As Int) As Boolean Return B4XPages.Delegate.Activity_KeyPress(KeyCode) End Sub But wich event is firing?

www.b4x.com

 

[mangojack]

Probably more correct is to keep this code in the 'Main' module ...

Sub Activity_KeyPress (KeyCode As Int) As Boolean  
    Return B4XPages.Delegate.Activity_KeyPress(KeyCode)  
End Sub

and in your Pages class module handle the back key in the Close_Request event.

Sub B4XPage_CloseRequest As ResumableSub  
    Return True
End Sub

ps: strangely , In a similar scenario test app, passing Return False did not cause a crash (as in your case) , just made back key unresponsive.

 

[Patrick Clark]

I do have everything as you have said apart from the Return False

The behaviour I want is to ignore the back key (unresponsive) but I get a crash.

 

[Erel]

Don't change anything in the template code.

But if the page that is currently displayed is the only page in the stack the app crashes when i press the back key

You should post the error message.