CODEWITHSUNDEEP
androidlistviewandroid-view
Crabime
Crabime

Reputation: 684

how to use arrayadapter.getview method

Here I defined a SiteAdapter and extends from ArrayAdapter:

public class SiteAdapter extends ArrayAdapter<Site> {
private int resourceId;
private List<Site> sites = null;
private Context context;
public SiteAdapter(Context context, int resource, List<Site> objects) {
    super(context, resource, objects);
    this.context = context;
    this.resourceId = resource;
    this.sites = objects;
}

@Override
public Site getItem(int position) {
    return sites.get(position);
}

@Override
public int getCount() {
    return sites.size();
}

//get the viewpage which inflate by site_layout.xml file
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    Site site = getItem(position);
    View view = convertView;
    if (view == null) {
        LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = vi.inflate(resourceId, null);
    }
    //this place we need to get the whole widget in site_layout.xml file
    ImageView i1 = (ImageView) view.findViewById(R.id.thumbnail);
    TextView address = (TextView) view.findViewById(R.id.address);
    TextView t1 = (TextView) view.findViewById(R.id.name);
    TextView t3 = (TextView) view.findViewById(R.id.distance);
    i1.setImageResource(site.getImageId());
    address.setText(site.getAddress());
    String name = site.getName();
    String result = parse(name);
    //set name of the view
    t1.setText(name);
    t3.setText("<" + site.getDistance() + "m");

    return view;
}

and in the MainActivity, I set the ListView using this site adapter, and I allocated an R.drawable.blank value to the only ImageView and now I need to change the ImageView, then get each row view through siteadapter getview method, the view returned but the question is why ImageView inside such view can't replace a new value(image), the result always turn out the previous R.drawable.blank ImageView:

here is MainActivity snippet:

View view = siteAdapter.getView(2, null, listView);
        ImageView image1 = ((ImageView)view.findViewById(R.id.thumbnail));
        image1.invalidate();
        image1.setImageResource(R.drawable.amap_end);
        siteAdapter.notifyDataSetChanged();

Upvotes: 2

Views: 2364

Answers (1)

Mehdi Jahed Manesh
Mehdi Jahed Manesh

Reputation: 2278

The point is you do not have to call getView() from your activity . It is only called by Adapter .

Now if you want to change your imageView , you should change it from your sites list that is links to your adapter from activity , then call notifyDataSetChanged() from adapter .

Activity : 

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);

        // setUpViews
        SiteAdapter adapter = new SiteAdapter(context,List<Site> sites);
        listView.setAdapter(adapter);

        // changing imageView
        Site site = sites.get(position);
        site.setImage(R.drawable.*);

        // updating site into list with new image
        sites.set(position,site);

        // refresh the listView
        adapter.notifyDataSetChanged();

However , consider to use RecycleView instead of ListView .

Upvotes: 1

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