Question

I’ve created a ListView from an SQLite database but am stuck on how to add a listener to each ListView item so that when an item is clicked I can display another page with more information on that item. The database is just a sample. Any help would be appreciated.

public class Database extends ListActivity {

private final String SAMPLE_DB_NAME = "myFriendsDb";
//private final String SAMPLE_TABLE_NAME = "friends";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    ArrayList<String> results = new ArrayList<String>();
    SQLiteDatabase db = null;

    try {
        db =  this.openOrCreateDatabase(SAMPLE_DB_NAME, MODE_PRIVATE, null);

        db.execSQL("CREATE TABLE IF NOT EXISTS people" +
                " (LastName VARCHAR, FirstName VARCHAR," +
                " Country VARCHAR, Age INT(3));");

        db.execSQL("INSERT INTO people" +
                " Values ('Jones','Bob','UK',30);");
        db.execSQL("INSERT INTO people" +
                " Values ('Smith','John','UK',40);");
        db.execSQL("INSERT INTO people" +
                " Values ('Thompson','James','UK',50);");

        Cursor c = db.rawQuery("SELECT FirstName, LastName FROM people", null);

        if (c != null ) {
            if  (c.moveToFirst()) {
                do {
                    String firstName = c.getString(c.getColumnIndex("FirstName"));
                    String lastName = c.getString(c.getColumnIndex("LastName"));
                    results.add("" + firstName + " " + lastName);
                }while (c.moveToNext());
            } 
        }

        this.setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,results));

    } catch (SQLiteException se ) {
        Log.e(getClass().getSimpleName(), "Could not create or Open the database");
    } finally {
        if (db != null) 
            db.execSQL("DELETE FROM people");
            db.close();
    }
}

}

Answer 1

there are many ways to solve your problem. One possible solution is this: you simply need to implement protected method onListItemClick(ListView l, View v, int position, long id) in your ListActivity.

public class Database extends ListActivity {

    //YOUR CODE ABOVE HERE...

    public static final String SHOWITEMINTENT_EXTRA_FETCHROWID = "fetchRow";
    public static final int ACTIVITY_SHOWITEM = 0; /*Intent request user index*/

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id){
        /*
        position variable holds the position of item you clicked...
        do your stuff here. If you want to send to another page, say another activity
        that shows your stuff, you can always use an intent
        example:
        */
        Intent tmpIntent = new Intent(this, YourActivityForShowingItem.class);
        tmpIntent.putExtra(SHOWITEMINTENT_EXTRA_FETCHROWID, position);
        startActivityForResult(tmpIntent, ACTIVITY_SHOWITEM);

    }
}

Alternately, you can access the ListView of your listActivity using getListView(), and call the setters for listeners or context menu as you would have done with a regular ListView object. For instance, this function that sets a listener using this approach:

private void setMyListListener(){
    getListView().setOnItemClickListener(new OnItemClickListener(){
        @Override
        public void onItemClick(AdapterView<?> a, View v, int position, long id){
            /*same fake code as above for calling another activity using an intent:*/
            Intent tmpIntent = new Intent(this, YourActivityForShowingItem.class);
            tmpIntent.putExtra(SHOWITEMINTENT_EXTRA_FETCHROWID, position);
            startActivityForResult(tmpIntent, ACTIVITY_SHOWITEM);
        }
    });
}

This function can be called by your onCreate(…) function afterwards if you want your click listener to be configured the same way for the whole duration of your activity.