How to get the index of a clicked item into another activity?

Question

I have a activity (Contato) that shows a ListView of the contacts i have in my database(banco > contatos > nome, telefone (database>table>rows)). When a Contact Info is clicked a Dialog comes up and shows me the info and 3 button (OK/Alterar/Delete) when i hit Alterar it sends me to another activity(Alterarcontato) which i have 2 Edit Texts and 1 Button. So when i get send to the Alterarcontato activity i still want to have the index o the Contact i clicked so I can change it's values ( with db.update).

Contato.java code ListView that shows the dialog and has it's index.

    ListView user = (ListView) findViewById(R.id.lvShowContatos);
    //String = simple value ||| String[] = multiple values/columns
    String[] campos = new String[] {"nome", "telefone"};

    list = new ArrayList<String>();
    c = db.query( "contatos", campos, null, null, null, null, null);
    c.moveToFirst();
    if(c.getCount() > 0) {
        while(true) {
           list.add(c.getString(c.getColumnIndex("nome")).toString());
            if(!c.moveToNext()) break;
        }
    }

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

    user.setAdapter(adapter);

    user.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            reg = position;
            c.moveToPosition(reg);
            String nome = c.getString(c.getColumnIndex("nome"));
            String telefone = c.getString(c.getColumnIndex("telefone"));
            ShowMessage(nome, telefone);
        }
    });

Alterarcontato.java code that has the editTexts and button to then alter the values.

              EditText nomeA = (EditText) findViewById(R.id.etNomeAlter);
            EditText telefoneA = (EditText) findViewById(R.id.etTelefoneAlter);

            final String nomeB = nomeA.getText().toString();
            final String telefoneB = telefoneA.getText().toString();

            String where = "id=?";
            String[] whereArgs = {"nome", "telefone"};

            ContentValues dataToInsert = new ContentValues();                          
            dataToInsert.put("nome", nomeB);
            dataToInsert.put("telefone", telefoneB);

            db.update("contatos", dataToInsert, where, whereArgs);

But as shown in Contato.java code i don't have any ID for the contacts, so the String where = "id=?"; is kinda of invalid, so how do i get the index already from Contact.java to get shown in the Alterarcontato.java so when i put some writing in it and hit the button, the values change in the database?

Thank you.

Answer 1

Have a look at this description on the Android Developers' site. It provides good step-by-step instructions. Essentially, you have to create an Intent and use the putExtra() method to pass the data.

Edit: Also, have a look at this answer to a similar question about getting the row ID in the ListActivity using onListItemClick().

Answer 2

    setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        reg = position;
        c.moveToPosition(reg);
        String nome = c.getString(c.getColumnIndex("nome"));
        String telefone = c.getString(c.getColumnIndex("telefone"));
        ShowMessage(nome, telefone);

        /// The above method will show the dialog with contact info right..? SO from the dialog you are launching the activity to edit the info. While starting the activity you have to pass the index. Like below :

           Intent intent = new Intent(getApplicationContext(), Alterarcontato.class);
           // the index is the variable which contains the index of the selected contact in your dialog.
       intent.putExtra("key", index);
           startActivity(intent);


    <-- Alterarcontato.java -->

public class Alterarcontato extends Activity {

    private Integer mIndex;


    @Override
    public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          mIndex = getIntent().getExtras().getInt("key");
    }
 }

Answer 3

You can try the given link, i hope this may help you

Contacts Contract API