ListView Generated from SQLite onClickListener() to take me to another activity based on where i clicked

Question

I'm creating an android app. In this app, I have a ListView populated with data from SQLite. I am trying to add an onClickEventListener to each row of the ListView so that when a menu item is clicked it opens up another Activity with more information from the Database about the item clicked. I have succeeded in adding an event listener to the ListView, but I am not sure how to pass on database information depending on the list item clicked.

Here is my code:

public class MainActivity extends AppCompatActivity {

private DatabaseHelper dbh;
private ArrayList listItems = new ArrayList();

ArrayList<String[]> noteList;
private ArrayAdapter adapter;
private ListView lv;

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

    dbh = new DatabaseHelper(this);
    dbh.open();

    lv = (ListView) findViewById(R.id.noteListView);

    noteList = dbh.selectAll();
    String id = "";
    String content = "";

    for(int i = 0; i < noteList.size(); i++){
        content = noteList.get(i)[1];
        id = noteList.get(i)[0];
        listItems.add(id + ", " + content);
    }

    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, listItems);

    lv.setAdapter(arrayAdapter);

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,int position, long id) {

            Intent i = new Intent(MainActivity.this, EditNote.class);

            //i.putExtra();

            startActivity(i);
        }
    });
}

}

you have a position and a list of items, what else do you need? — njzk2, Apr 25 '17 at 14:42

score 0 · Answer 1 · edited May 23 '17 at 11:54

You should make a custom adapter that extends the arrayadapter. Load everything from your database into an arraylist and use something like this:

// CODE DOES NOT WORK WITH YOUR CODE, IT'S JUST AN EXAMPLE
public class MyClassAdapter extends ArrayAdapter<MyClass> {

    private static class ViewHolder {
        private TextView itemView;
    }

    public MyClassAdapter(Context context, int textViewResourceId, ArrayList<MyClass> items) {
        super(context, textViewResourceId, items);
    }

    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            convertView = LayoutInflater.from(this.getContext())
            .inflate(R.layout.listview_association, parent, false);

            viewHolder = new ViewHolder();
            viewHolder.itemView = (TextView) convertView.findViewById(R.id.ItemView);

            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        MyClass item = getItem(position);
        if (item!= null) {
            // My layout has only one TextView
                // do whatever you want with your string and long
            viewHolder.itemView.setText(String.format("%s %d", item.reason, item.long_val));
        }

        return convertView;
    }
}
...
lv.setAdapter(new MyClassAdapter(....));

In your OnItemClickListener you have the position of the clicked item so to get the object use MyClass object = lv.getItemAtPosition(position); and use that object to pass data to the new activity.

Intent intent = new Intent(getBaseContext(), my.class);
intent.putExtra("key", "value");
startActivity(intent);

To access

String s = getIntent().getStringExtra("key");

More: https://stackoverflow.com/a/2265712/2890156

Rohit Singh · Accepted Answer · 2017-07-31T12:35:05.057

In your case list has strings, so here is what you need to do:

String yourString = listItem.get(position);
i.putExtra("KEY", yourString);
startActivity(i);

And at the receiving activity you can retrieve as

intent intent = getIntent();
String yourString = intent.getExtras().getString("KEY");

EDIT: If your list is having some POJO class or simple class objects

You can pass to second activity like this

intent.putExtra("Your class", obj);

To retrieve object in second Activity

getIntent().getSerializableExtra("Your class");

EDIT: One important thing to remember.

If you passing a class object it must implement Serializable or Parcelable interface.
For eg

class Student implements Serializable{

}

ListView Generated from SQLite onClickListener() to take me to another activity based on where i clicked

2 Answers2