Android Question Back key and home key on the device

[ciginfo]

What do exactly the Back key and the Home key on the device in B4A
Close app ? Close activity ? I don't understand exactly when i read thé guides
Thank you

 

[Erel]

Tip: switch to B4XPages and everything will be simpler.

In non-B4XPages the back button destroys the current activity and the home button pauses the activity and shows the home screen.
In B4XPages the back button hides the current page. Pages are never paused or destroyed. The home button moves the app to the background.

 

[beltrao73]

I tried this code to prevent back key from closing app:

Sub B4XPage_CloseRequest As ResumableSub
    Return False
End Sub

But got this error:

Error occurred on line: 504 (B4XPagesManager)
java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.keywords.Common.CallSubDebug(Common.java:1050)
at tecsoft.ArgosGerente.b4xpagesmanager$ResumableSub_HandleCloseRequest.resume(b4xpagesmanager.java:814)
at tecsoft.ArgosGerente.b4xpagesmanager._handlecloserequest(b4xpagesmanager.java:784)
at tecsoft.ArgosGerente.b4xpagesmanager._activity_keypress(b4xpagesmanager.java:542)
at tecsoft.ArgosGerente.b4xpagesdelegator._activity_keypress(b4xpagesdelegator.java:66)
at tecsoft.ArgosGerente.main._activity_keypress(main.java:435)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at tecsoft.ArgosGerente.main$HandleKeyDelayed.runDirectly(main.java:231)
at tecsoft.ArgosGerente.main$HandleKeyDelayed.run(main.java:228)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:241)
at android.app.ActivityThread.main(ActivityThread.java:7582)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)
Caused by: java.lang.RuntimeException: java.lang.Exception: Sub B4XPage_CloseRequest was not found.
at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:336)
at anywheresoftware.b4a.debug.Debug.CallSubNew(Debug.java:282)
... 22 more
Caused by: java.lang.Exception: Sub B4XPage_CloseRequest was not found.
at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:326)

 

[Brian Dean]

Sub B4XPage_CloseRequest As ResumableSub
    Return False
End Sub

This does work - it prevents the app closing. This statement is not itself causing your error - the error is happening because you have a coding problem somewhere else.

 

[Erel]

tried this code to prevent back key from closing app:

You should never post questions in existing threads.