尝试在空对象引用上调用虚拟方法 'android.view.ViewGroup$LayoutParams android.view.View.getLayoutParams()'

Question

I am making a simple Android list view app which will show some basic name, in list view. My app is stopping unexpectedly. The logcat is showing this error.

Attempt to invoke virtual method 'android.view.ViewGroup$LayoutParams android.view.View.getLayoutParams()' 
    on a null object reference.

CustomAdapter

public class CustomAdapter extends BaseAdapter {

    Context context;
    String animals[];
    LayoutInflater inflater;

    public CustomAdapter(Context applicationContext, String[] animals){
        this.context = applicationContext;
        this.animals = animals;
        inflater = (LayoutInflater.from(applicationContext));

    }
    @Override
    public int getCount() {
        return animals.length;
    }

    @Override
    public Object getItem(int i) {
        return null;
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        view = inflater.inflate(R.layout.listview, null);
        TextView textView = (TextView) view.findViewById(R.id.tv);
        textView.setText(animals[i]);
        return null;
    }
}

Main Activity

public class MainActivity extends AppCompatActivity {

    ListView listView;
    String animals[]= {"Dog", "Cat", "Humans", "Monkey", "Rat", "Snake", "Elephant", "Giraffe", "Deer", "Tiger", "Lion","Cow", "Pig", "Goat"};

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

        listView =(ListView) findViewById(R.id.lv);
        CustomAdapter customAdapter = new CustomAdapter(getApplicationContext(), animals);
        listView.setAdapter(customAdapter);
     }
}

Answer 1

Here you did Mistakes

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
view = inflater.inflate(R.layout.listview, null);
TextView textView = (TextView) view.findViewById(R.id.tv);
textView.setText(animals[i]);
return view;
}

And

public long getItemId(int i) {
    return animals.length;
}

Screenshort