BaseAdapter GetView returning NullPointer Exception

Question

This is my Base Adapter and I am trying to inflate a GridView with Images from drawable. As it turns out, it returns NullPointerExceptipn. But when I change getCount() return value to 0, it does not show exception anymore but the gridview does not show up. I have taken out the log of build_list and it has data in it.

public class BuildingListAdapter extends BaseAdapter {

Context context;
ArrayList<Building> build_list = new ArrayList<Building>();

public BuildingListAdapter(Context c, ArrayList<Building> build_list) {
    // TODO Auto-generated constructor stub
    context = c;
    this.build_list.addAll(build_list);
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return build_list.size();
}

@Override
public Building getItem(int position) {
    // TODO Auto-generated method stub
    return build_list.get(position);
}

@Override
public long getItemId(int arg0) {
    // TODO Auto-generated method stub
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    Log.v("CheckifRun", "true");
    Building building = this.getItem(position);
    ImageView img_view = new ImageView(convertView.getContext());
    int resID = convertView.getResources().getIdentifier(building.getBuild_img(), "drawable", "com.vapp.yangonuniversity");
    Log.v("resourceID", Integer.toString(resID));
    img_view.setImageResource(resID);
    img_view.setScaleType(ScaleType.CENTER_CROP);
    img_view.setLayoutParams(new GridView.LayoutParams(70, 70));
    return img_view;
}


}

At which line you getting exception? – Pratik Dasa Jun 25 '14 at 06:08 — Pratik Dasa, Jun 25 '14 at 06:08

score 1 · Accepted Answer · edited May 23 '17 at 12:20

change getView method to:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    Log.v("CheckifRun", "true");
    Building building = this.getItem(position);
    ImageView img_view = new ImageView(context);
    int resID = context.getResources().getIdentifier(building.getBuild_img(), "drawable", "com.vapp.yangonuniversity");
    Log.v("resourceID", Integer.toString(resID));
    img_view.setImageResource(resID);
    img_view.setScaleType(ScaleType.CENTER_CROP);
    img_view.setLayoutParams(new GridView.LayoutParams(70, 70));
    return img_view;
}

you need your context for creating ImageView and get data from Resource

what have Changed ?

ImageView img_view = new ImageView(context);

and

int resID = context.getResources().getIdentifier(building.getBuild_img(), "drawable", "com.vapp.yangonuniversity");

Update

you got OutOfMemomryException,

Why?

OutofMemory occurs when your app exceeds memory allocated in heap. The bitmap is too large to fit in memory ie heap

How to fix this issue?

you can search about that in google to find many related question, for start you can see:

Strange out of memory issue while loading an image to a Bitmap object

It did fix the error but it's now showing "out Of Memory Error" — Vincent Paing, Jun 25 '14 at 06:14

BaseAdapter GetView returning NullPointer Exception

1 Answers1