Android custom ListView items (findViewById returns null)

Question

I'm trying to populate custom ListView with this LazyAdapter class from this tutorial

I want to make list view items with custom design. Layout file list_row.xml is in my layouts file just like in the tutorial. This is a slightly modified getView function in LazyAdapter class:

public View getView(int position, View convertView, ViewGroup parent) {
    View vi=convertView;
    if(convertView==null)
        //vi = inflater.inflate(R.layout.list_row, null);    //EDITED
        vi = inflater.inflate(R.layout.list_row, parent, false);
    TextView title = (TextView)vi.findViewById(R.id.title); // title
    TextView subtitle = (TextView)vi.findViewById(R.id.subtitle); // artist name
    //ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image);

    //This is not needed
    //HashMap<String, String> post = new HashMap<String, String>();
    HashMap<String, String> post;
    post = data.get(position);
    // Setting all values in listview
    title.setText(post.get("title"));     //the code crashes here
    subtitle.setText(post.get("subtitle"));
    //imageLoader.DisplayImage(song.get(CustomizedListView.KEY_THUMB_URL), thumb_image);
    return vi;
}

Well this code crashes at title.setText(), because the title is null. I read somewhere that this makes sense because this LazyAdapter is calling findViewById before setContentView or something..

So how do I have to do this? And how does this code work for that guy?

Update

This is the list_row.xml file:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/list_selector"
    android:orientation="horizontal"
    android:padding="5dip" >

    <!-- Title -->
    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#040404"
        android:typeface="sans"
        android:textSize="14sp"
        android:textStyle="bold"/>

    <!-- Subtitle -->
    <TextView
        android:id="@+id/subtitle"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/subtitle"
        android:textColor="#343434"
        android:textSize="10sp"
        android:layout_marginTop="1dip" />

</RelativeLayout>

To save space I'm only adding ListView xml from the main activity layout file:

<ListView
    android:id="@+id/feedListView"
    android:layout_marginTop="20dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/volumeControl1">
</ListView>

Adapter code: http://pastebin.com/niC1yXiJ

And the stack trace: http://pastebin.com/myW8B0Xz

Answer 1

This was a hell of a ride (two sleepless nights). Thanks for all your help, somehow I fixed it! :)

Mostly thanks to this question Null pointer exception in getView() of custom Adapter I made new getView function:

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder = new ViewHolder();
    View vi = convertView;
    if (vi == null) {
        LayoutInflater inflater = ((Activity)activity).getLayoutInflater();
        vi = inflater.inflate(R.layout.list_row, null);
        holder.title = (TextView) vi.findViewById(R.id.title);
        holder.subtitle = (TextView) vi.findViewById(R.id.subtitle);
        vi.setTag(holder);
    } else {

        holder = (ViewHolder) vi.getTag();
    }
    HashMap<String, String> post;
    post = data.get(position);
    holder.title.setText(post.get("title"));
    holder.subtitle.setText(post.get("subtitle"));
    return vi;
}

holder is just a simple class:

private class ViewHolder {
    public TextView title;
    public TextView subtitle;
}

I've done that and I also copied xml drawable files in all drawable folders (merged all). So one of this actions fixed it, but I'm not quite sure what..

Answer 2

Try passing in the parent when you inflate your cell. Using this method:

public View inflate (int resource, ViewGroup root, boolean attachToRoot)

vi = inflater.inflate(R.layout.list_row, parent, false);

Answer 3

If you get android.widget.AbsListView.obtainView(AbsListView.java:1408) exception than your returned View of getView() is probably null.So check first of all that you are not return null view.