I’m not able to exbir a listview that uses an Arrayadapter<String>

Question

I have a main class that inherits from Activity where I have my views, but I needed to create another class that inherits Arrayadapter. However I am not able to present my listview, the strange thing is that when you take an item from the list and print it works. Can someone give a help? Thank you in advance!

This method is in my class that inherits Activity. This is the method to fill Activity that is not showing anything.

//recebo um vetor de String com dados do banco
public void preencheListView(String[] paises) {

        lv = new ListView(this);
        //instancio aqui
        adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, paises);
        //aqui eu consigo imprimir um pais para teste, o que significa que o adapter está ok
        System.out.println("teste: "+adapter.getItem(1));
        lv.setAdapter(adapter);
        lv.setOnItemClickListener(this);
        linearlayout.addView(lv);

    }
}

This is my class who inherits Arrayadapter

public class ArrayAdapter extends ArrayAdapter<String> {

    public Context ctx;
    public int rec;
    public String[] paises;



    public ArrayAdapter(Context context, int resource, String[] p) {
        super(context, android.R.layout.simple_list_item_1, p);
        this.ctx = context;
        this.rec = resource;
        this.paises = p;
    }

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        return null;
    }

    public int getRec() {
        return rec;
    }

    public void setRec(int rec) {
        this.rec = rec;
    }

    public Context getCtx() {
        return ctx;
    }

    public void setCtx(Context ctx) {
        this.ctx = ctx;
    }

    public String[] getPaises() {
        return paises;
    }

    public void setPaises(String[] paises) {
        this.paises = paises;
    }


}

Note: Before I created the class Arrayadapter worked well, but I had to create the Arrayadapter because I will need to use the getView().

Note 2: I put one adapter.getCount() now and found that the Adapter is really empty, but print the item, with the adapter.getItem(x);

Note: I am calling the Arrayadapter class in the correct way?

Answer 1

The problem is in the method

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
         // TODO Auto-generated method stub
         return null;
    }

It should not return null, but it should return a View which will be the item of your ListView, then within your method getView make the following code:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    return super.getView(position, convertView, parent);
}

You must implement the methods add and getItem also. In this way:

@Override
public void add(String value) {
    super.add(object);
}

@Override
public String getItem(int position) {
    return super.getItem(position);
}

Not implementing the methods will also solve your problem. If you don’t need to implement the method, or don’t @Override or always call the code super class, this way: super.METODO

Answer 2

In your Adapter I saw that you are returning 0 in the getCount method in this snippet of your code:

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

Try returning the size of your String Array instead:

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

And also in the getItemId method has to return the position that is sent as parameter:

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

So you can return the getCount of your object correctly and also return the id of each item that is nothing more than the position of the item itself.