Android Question Attempt to invoke virtual method 'java.lang.Object java.lang.ref.WeakReference.get() [SOLVED]

[AHilberink]

Hi,

I do this:

Sub TellenUren(Controle As Boolean) As ResumableSub
    Wait For(Test(Controle)) Complete (Result As Int)
    Log("result: " & Result)
    Log("after sum")
    
    Return 0
End Sub


Sub Test(Para As Boolean) As ResumableSub
    If(Para) Then
        Return 1
    Else
        Return 0
    End If
End Sub

And I got this Crash:

uren$ResumableSub_TellenUrenresume (java line: 4346)
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.WeakReference.get()' on a null object reference
    at anywheresoftware.b4a.keywords.Common.WaitFor(Common.java:1834)
    at ciris.chauffeur.uren$ResumableSub_TellenUren.resume(uren.java:4346)
    at ciris.chauffeur.uren._tellenuren(uren.java:4322)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:221)
    at anywheresoftware.b4a.keywords.Common.CallSub4(Common.java:1167)
    at anywheresoftware.b4a.keywords.Common.CallSubNew2(Common.java:1122)
    at ciris.chauffeur.uren$ResumableSub_HeenVT_FocusChanged.resume(uren.java:2699)
    at ciris.chauffeur.uren._heenvt_focuschanged(uren.java:2627)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:221)
    at anywheresoftware.b4a.BA$1.run(BA.java:360)
    at android.os.Handler.handleCallback(Handler.java:1001)
    at android.os.Handler.dispatchMessage(Handler.java:105)
    at android.os.Looper.loopOnce(Looper.java:268)
    at android.os.Looper.loop(Looper.java:384)
    at android.app.ActivityThread.main(ActivityThread.java:8936)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:907)

I use this to start:

Wait For (CallSub2(Me,"TellenUren",False)) Complete (dummy As Object)

What can be wrong?

Kind regards,
André

 

[William Lancee]

I changed your Wait For statement. Then it works as expected.

    Wait For (TellenUren(False)) Complete (dummy As Object)

 

[AHilberink]

I changed your Wait For statement. Then it works as expected.

    Wait For (TellenUren(False)) Complete (dummy As Object)

Hi William,

Thank you for your reply. Unfortunally I still got the same crash after changing the Wait For. Is there something else I can check?

Kind regards,
André

 

[AHilberink]

Hi William,

Thank you for your reply. Unfortunally I still got the same crash after changing the Wait For. Is there something else I can check?

Kind regards,
André

Hi Again,

I tested it with a new, small progamm and it worked as expected. Donn't know why. I will try to find the cause by rebuilding that part of my App.

Kind regards,
André

 

[AHilberink]

Hi William and others,

The problem seems to be solved by rebuilding the part of my app. The cause could be a StringToNumber conversie on a empty string on a seperate Sub, but not sure about this.

It is working now. Thanks for helping.

Kind regards,
André

 

[William Lancee]

I am a few hours later here in Canada, so I just started looking at this.
Since I had tested your small example myself and it worked, my suggestion would have been to look
in other parts of your code for the source of the error. But I see you found a solution (if not the actual bug).