Android Question expected receiver of type anywheresoftware.b4a.AbsObjectWrapper

[Frank Cazabon]

My code is crashing on the second line below whenever a bluetooth scanner is connected to my tablet.

Public Sub AddItemsToList(li As List, full As String)
    If li.IsInitialized = False Then Return

The error is:

java.lang.NullPointerException: expected receiver of type anywheresoftware.b4a.AbsObjectWrapper, but got null

What am I doing wrong?

 

[Erel]

How do you call this method?

 

[Frank Cazabon]

Here's the short version of how it is getting called at this time:

Sub Activity_Create(FirstTime As Boolean)
   
    svwAWB.Initialize(Me, "svwAWB")
    svwDelivery.Initialize(Me, "svwDelivery")

    Activity.LoadLayout("MainMenu")

    tbhMain.AddTab("Select Route","SelectRoute")
    tbhMain.AddTab("Load","Load")
    tbhMain.AddTab("Approve","Approve")
    tbhMain.AddTab("Deliver","Deliver")
    tbhMain.AddTab("Upload","Upload")

    If FirstTime Then
   
        Dim DeliveryAWBs As List
        DeliveryAWBs = BuildDeliveryList
        DeliveryIndex = svwDelivery.SetItems(DeliveryAWBs)

        Dim AWBs As List
        AWBs = BuildLoadList
        AWBIndex = svwAWB.SetItems(AWBs)
    Else
        svwAWB.SetIndex(AWBIndex)
        svwAWB.AddItemsToList(AWBs, "") ' this seems to be where it is being called.
        svwDelivery.SetIndex(DeliveryIndex)
        svwDelivery.AddItemsToList(DeliveryAWBs, "")
       
    End If

 

[Frank Cazabon]

OK, that question got me thinking and apparently AWBs at that point in time shows up as "Error evaluating expression" in the Watch window. SO I guess I need to check if AWBs exists at that point in time. How would I do that?

 

[Erel]

I guess that there is another piece of code that calls this method (when a Bluetooth is connected).

Try to check whether li is Null:

If li = Null Or li.IsInitialized = False Then Return

 

[Frank Cazabon]

Tried that but get this error now:

java.lang.RuntimeException: Unexpected command: 0

The activity create seems to get called when the bluetooth device is connected.

 

[Frank Cazabon]

I think I've got it.

I needed to declare the AWBs List in the Process_Globals section.