Android listview is returning null?

Question

So I'm trying to make a tabbed application...But it keeps crashing with null pointer exception . I checked through all the variables that could be causing a null pointer and I think I've narrowed it down.

ListView activeList = (ListView) findViewById(R.id.activelist);
if(activeList == null) {
  Log.e("com.name.app", "activeList null");
}

This returns a null. Should it? I'm using fragments to try and build a tabbed layout. This is the xml it's referencing.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" 
    >

    <ListView
        android:id="@+id/activelist"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:persistent="true" >    
    </ListView>

</LinearLayout>

Thank you for any help!

Edit:

    super.onCreate(savedInstanceState);
    setContentView(R.layout.tabs_layout);

That's what my contentview looks like.

Edit: This is what my final code looked like!

    LayoutInflater inflater = (LayoutInflater)   getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    LinearLayout mContainer = (LinearLayout)     inflater.inflate(R.layout.tab_frag1_layout, null); 
    ListView activeList = (ListView) mContainer.findViewById(R.id.activelist);

Look if that listview is declared in the same layout which you are setting as a content of that activity. — hardartcore
– hardartcore, Commented Sep 7, 2012 at 8:22
It is not, but now I'm trying to figure out how to inflate that. Is there any easy way? — Lethjakman
– Lethjakman, Commented Sep 7, 2012 at 8:33

Iulia Barbu · Accepted Answer · 2017-05-16 12:09:45Z

4

LinearLayout mContainer = inflater.inflate(R.layout.linear_layout, null); 
ListView activeList = (ListView) mContainer.findViewById(R.id.activelist);

Where R.layout.linear_layout is the id of LinearLayout which contains your ListView.

edited May 16, 2017 at 12:09

answered Sep 7, 2012 at 8:36

Iulia Barbu

1,53012 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Lethjakman Over a year ago

By RelativeLayout do you mean LinearLayout? Would I have to add an ID to the LinearLayout I have posted above? What would the inflater variable look like?

Iulia Barbu Over a year ago

I modified with linearlayour but fro this issue it will be the same. I'm not sure where exactly you want to "inflate" your list.

Lethjakman Over a year ago

R.layout.linear_layout <-- Where's that supposed to be in my xml?

Iulia Barbu Over a year ago

post your R.layout.tabs_layout please

Lethjakman Over a year ago

Oh wait! I got it! I'll post my final code above. Thank you all for your help!

PoeHaH · Accepted Answer · 2012-09-07 08:21:59Z

1

Did you reffer in your activity to your XML layout?

You can do this in your oncreate method:

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView.(R.layout.your_XML_file_name);
}

answered Sep 7, 2012 at 8:21

PoeHaH

1,9363 gold badges29 silver badges53 bronze badges

2 Comments

Lethjakman Over a year ago

Oh! No I have another ContentView selected, but that's necessary. But I believe I need to inflate the textview that I need to use?

PoeHaH Over a year ago

does this work? ListView tv = (ListView ) getLayoutInflater().inflate(R.layout.yourLV, null);

Collectives™ on Stack Overflow

Android listview is returning null?

2 Answers 2

5 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related