Using ArrayAdapter to create a list in Android

Question

I'm new at this and an explanation of how things work would be really useful.

So I have this class

        static class ListAdapter extends ArrayAdapter<String>{
            List<String> elements;
            Context context;

            public ListAdapter(Context context, List<String> elements) {
                super(context, 0, elements);
                this.context = context;
                this.elements = elements;
            }


            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                if (convertView == null) {
                    convertView = LayoutInflater.from(context).inflate(R.layout.list_item_ex, null, false);
                }

                TextView tvTitle = convertView.findViewById(R.id.tv_title);
                TextView tvDescription = convertView.findViewById(R.id.tv_description);
                ImageView ivExample = convertView.findViewById(R.id.iv_image);

                ivExample.setImageResource(R.drawable.offer_1);
                tvTitle.setText(elements.get(position));
                tvDescription.setText(String.valueOf(position));

                return convertView;
            }
        }

I added in MainActivity a few elements to the list to see how it works, but I'm having a hard time to understand how you can add elements, each with different picture, description etc.

Answer 1

To do this you have To create an ArrayAdapter with a custom class : Here is the steps you have to folow :

1. create class Custom

   public class Custom {
   int image;
   String title;
   String description;
   //constructeur 
   //getters and setters }
   

2. create adapter extends ArrayAdapter

   public class CustomArrayAdapter extends ArrayAdapter<Custom> {
   
   ArrayList<Custom> list;
   
       public CustomArrayAdapter(Context context, ArrayList<Custom> list) {
       super(context, R.layout.list_item_ex, list);this.list = list;
   }
   
   
   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
   
       Custom custom=getItem(position);
   
       if (convertView == null) {
           convertView = LayoutInflater.from(getContext()).inflate(R.layout.list_item_ex, parent, false);
       }
   
       TextView tvTitle = convertView.findViewById(R.id.tv_title);
       TextView tvDescription = convertView.findViewById(R.id.tv_description);
       ImageView ivExample = convertView.findViewById(R.id.iv_image);
   
       ivExample.setImageResource(custom.getImage());
       tvTitle.setText(custom.getTitle());
       tvDescription.setText(custom.getDescription());
   
       return convertView;
   }
   

   }

3. fill an ArrayList and then listView.setAdapter(customArrayAdapter);

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
   
       ListView listView=(ListView) findViewById(R.id.listView) ;
       ArrayList<Custom> list=new ArrayList<>();
       list.add(new Custom(R.mipmap.ic_launcher,"title","desc"));
   
       CustomArrayAdapter customArrayAdapter=new CustomArrayAdapter(this,listView);
   
       listView.setAdapter(customArrayAdapter);}