Android - Issue with lazy loading listview

Question

I have successfully implemented lazy loading for the listview. Everything is alright; loading of images and text. I have 2 piece of information for text; Name and description. I am able to display flawlessly the image and name. But once I try to include the description in it, it seems alright until a certain position. Program is forced closed at that position. Can't figure out what is causing it to close. Any idea what could be the cause? Results displayed on logcat only prints till about half of total number of items to be print.

Program is able to retrieve all images and display them correctly. This is for sure. But having problem retrieving the whole piece of text content. It only retrieves half of the total text available.

I am using the example from here.

LazyAdapter.java

public class LazyAdapter extends BaseAdapter {

private Activity activity;
private String[] data;
private String[] text;
private static LayoutInflater inflater=null;
public ImageLoader imageLoader; 

public LazyAdapter(Activity a, String[] d, String[] t) {
    activity = a;
    data=d;
    text = t;
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    imageLoader=new ImageLoader(activity.getApplicationContext());
}

public int getCount() {
    return data.length;
}    

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}

public static class ViewHolder{
    public TextView text;
    public ImageView image;
}

public View getView(int position, View convertView, ViewGroup parent) {
    View vi=convertView;
    ViewHolder holder;
    if(convertView==null){
        vi = inflater.inflate(R.layout.item, null);
        holder=new ViewHolder();
        holder.text=(TextView)vi.findViewById(R.id.text);;
        holder.image=(ImageView)vi.findViewById(R.id.image);
        vi.setTag(holder);
    }
    else
        holder=(ViewHolder)vi.getTag();

    holder.text.setText(text[position]);
    holder.image.setTag(data[position]);
    imageLoader.DisplayImage(data[position], activity, holder.image);
    return vi;
}
}

Error exception in logcat is shown below.

ERROR/AndroidRuntime(270): java.lang.ArrayIndexOutOfBoundsException
ERROR/AndroidRuntime(270):     at com.lazy.LazyAdapter.getView(LazyAdapter.java:59)
ERROR/AndroidRuntime(270):     at android.widget.AbsListView.obtainView(AbsListView.java:1294)
ERROR/AndroidRuntime(270):     at android.widget.ListView.makeAndAddView(ListView.java:1727)
ERROR/AndroidRuntime(270):     at android.widget.ListView.fillDown(ListView.java:652)
ERROR/AndroidRuntime(270):     at android.widget.ListView.fillGap(ListView.java:623)
ERROR/AndroidRuntime(270):     at android.widget.AbsListView.trackMotionScroll    (AbsListView.java:2944)
ERROR/AndroidRuntime(270):     at android.widget.AbsListView$FlingRunnable.run   (AbsListView.java:2485)
ERROR/AndroidRuntime(270):     at android.os.Handler.handleCallback(Handler.java:587)
ERROR/AndroidRuntime(270):     at android.os.Handler.dispatchMessage(Handler.java:92)
ERROR/AndroidRuntime(270):     at android.os.Looper.loop(Looper.java:123)
ERROR/AndroidRuntime(270):     at android.app.ActivityThread.main(ActivityThread.java:4627)
ERROR/AndroidRuntime(270):     at java.lang.reflect.Method.invokeNative(Native Method)
ERROR/AndroidRuntime(270):     at java.lang.reflect.Method.invoke(Method.java:521)
ERROR/AndroidRuntime(270):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
ERROR/AndroidRuntime(270):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
ERROR/AndroidRuntime(270):     at dalvik.system.NativeStart.main(Native Method)

I printed my results on logcat and everything is fine. Retrieved results are perfectly correct. But error shows - 07:42:42.230: ERROR/AndroidRuntime(270): java.lang.ArrayIndexOutOfBoundsException, 07:42:42.230: ERROR/AndroidRuntime(270): at tp.edu.sg.LazyAdapter.getView(LazyAdapter.java:59) — Hend
– Hend, Commented Dec 12, 2011 at 7:46
does the problem appear when you scroll to most bottom item? — Marek Sebera
– Marek Sebera, Commented Dec 12, 2011 at 7:50
"But error shows..." - So why didn't you put that in your question as well as the code which is causing that exception? You asked "Any idea what could be the cause?", the answer is NO. Unless you show code and exceptions, nobody can help you. If you want an answer then you need to provide a good question. — Squonk
– Squonk, Commented Dec 12, 2011 at 7:51
Marek, It only appears after I reach a certain position. About halfway through. MisterSquonk, My bad on the asking of question. I have included more info about my problem — Hend
– Hend, Commented Dec 12, 2011 at 8:20

Sagar G. · Accepted Answer · 2013-04-19 10:18:24Z

2

The array or the array list you are sending to the adapter might be from some other activity, the list should have been initialized outside of onCreate() of that Activity so it's not getting renewed every time you load your list.

So probable solution is initialize it inside onCreate. For example:

public static List<ClassObject> myList;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.create_event_main);
    myList= new ArrayList<ClassObject>();
    <b>/***Then set the adapter******/</b>

    ListView lv;
    lv = (ListView)findViewById(R.id.cem_listview);
    adapter = new LazyAdapter(MyActivity.this, R.layout.MyActivity,myList);
    lv.setAdapter(adapter);
}

edited Apr 19, 2013 at 10:18

answered Sep 20, 2012 at 15:02

Sagar G.

5347 silver badges16 bronze badges

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

Comments

Konstantin Pribluda · Accepted Answer · 2011-12-12 07:58:22Z

1

Apparently you goofed with dereferencing some array / array list in your datapter at LazyAdapter.java:59 . In case this was last entry, you have most probably off-by-one error

Writing and executing meaningful unit tests would save you from this condition.

answered Dec 12, 2011 at 7:58

Konstantin Pribluda

12.3k1 gold badge33 silver badges38 bronze badges

Collectives™ on Stack Overflow

Android - Issue with lazy loading listview

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related