Android Question Problem with types

grafsoft · Apr 25, 2016

I have several iconbuttons and mist find the one with a certain tag. But when I want to work with it, I get
"java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.ViewGroup$LayoutParams com.phillipcalvin.iconbutton.IconButton.getLayoutParams()' on a null object reference"

Why?

B4X:

Dim clickedbtn as IconButton
For Each v As View In Activity.GetAllViewsRecursive
     Try
       ' only check iconbuttons
       If v Is IconButton Then
         t=v.Tag
         Log (t)
         If t=clickedno Then
           clickedbtn=v
           ' the next line throws the error
           Log (clickedbtn.Left & " - " & clickedbtn.Top)
         End If
       End If
     Catch
       Basis.debuginfo (LastException.Message,False)  
       
     End Try
         
   Next

DonManfred · Apr 25, 2016

v is a VIEW. Views does not have a Tag.
You need to cast v to a IconButton to get the IconButtons Tag.

B4X:

Dim clickedbtn as IconButton
For Each v As View In Activity.GetAllViewsRecursive
     Try
       ' only check iconbuttons
       If v Is IconButton Then
        dim btn as IconButton = v
         t=btn.Tag
         Log (t)
         If t=clickedno Then
           clickedbtn=v
           ' the next line throws the error
           Log (clickedbtn.Left & " - " & clickedbtn.Top)
         End If
       End If
     Catch
       Basis.debuginfo (LastException.Message,False) 
      
     End Try
        
   Next

grafsoft · Apr 25, 2016

Thank you, bit this did not help. The error message remains.

And then, this does not work:

B4X:

Dim bb As BitmapDrawable
bb.Initialize(Basis.CreateScaledBitmap2(LoadBitmap(File.DirAssets,"ic_play_black_48dp.png"), 40dip, 40dip, True))
clickedbtn.setIcon (False,bb)

It throws no error, but it does not work. If I say "clickedbtn is the newest button" - it works, but on the wrong button.

DonManfred · Apr 25, 2016

sorry, my code was wrong. maybe this is the problem

B4X:

For Each v As View In Activity.GetAllViewsRecursive
     Try
       ' only check iconbuttons
       If v Is IconButton Then
        dim btn as IconButton = v
         t=btn.Tag
         Log (t)
         If t=clickedno Then
           ' the next line throws the error
           Log (btn.Left & " - " & btn.Top)
         End If
       End If
     Catch
       Basis.debuginfo (LastException.Message,False)
     
     End Try
       
   Next

DonManfred · Apr 25, 2016

grafsoft said:
And then, this does not work

This is another issue! You should start a new thread for any new question.

grafsoft · Apr 26, 2016

Is it really? The problem is - I need to find the iconbutton with a certain tag and cast a global variable to it which I can use in another part of the program.

DonManfred · Apr 28, 2016

grafsoft said:
and cast a global variable to it which

Your code in post #1 does not tell this requirement that there is a gobal variable

Create a global variable

B4X:

Dim clickedbtn as IconButton

and then you can use it like this i guess

B4X:

For Each v As View In Activity.GetAllViewsRecursive
     Try
       ' only check iconbuttons
       If v Is IconButton Then
        dim btn as IconButton = v
        clickedbtn = btn
         t=btn.Tag
         Log (t)
         If t=clickedno Then
           ' the next line throws the error
           Log (btn.Left & " - " & btn.Top)
         End If
       End If
     Catch
       Basis.debuginfo (LastException.Message,False)
    
     End Try
      
   Next

If not i guess you should post a project which shows the problem.

grafsoft · Apr 29, 2016

Thank you Manfred!

I had help and the problem was found: I created buttons on top of each other. Case closed.

Android Question Problem with types

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