Question

I need some type of explanation as to how I can pass any database column value I want from the database for a listview item.

I would like to be able to grab any value, and pass it through to another activity via putExtras. I know how to do that part, what I don’t have a strong grasp of is how to get the value I want from the listview before sending it through the intent.

Here is my code and some more details to help you help me:

Day.java:

package com.dd.gfit;

public class Day {

    private long id;
    private long id_routine;
    private String name;
    private String day;

    public long getId() { return id; }  
    public long getIdRoutine() { return id_routine; }   
    public String getName() { return name; }    
    public String getDay() { return day; }

    public void setId(long id) { this.id = id; }    
    public void setIdRoutine(long id_routine) { this.id_routine = id_routine; } 
    public void setName(String name) { this.name = name; }  
    public void setDay(String day) { this.day = day; }

} 

This is where the values are stored and retreived. I get that.

DaysDataSource.java:

package com.dd.gfit;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

public class DaysDataSource {

    private SQLiteDatabase database;
    private MySQLiteHelper dbHelper;
    private String[] allColumns = { MySQLiteHelper.COLUMN_ID, MySQLiteHelper.COLUMN_ID_ROUTINE, MySQLiteHelper.COLUMN_NAME, MySQLiteHelper.COLUMN_DAY };

    public DaysDataSource(Context context) {
        dbHelper = new MySQLiteHelper(context);
    }

    public void open() throws SQLException {
        database = dbHelper.getWritableDatabase();
    }

    public void close() {
        dbHelper.close();
    }

    public Cursor fetchAllDays(long id) {     
        Cursor cursor = database.query(MySQLiteHelper.TABLE_DAYS, allColumns, MySQLiteHelper.COLUMN_ID_ROUTINE + " = " + id, null, null, null, null);
        if (cursor != null) { cursor.moveToFirst(); }
        return cursor;
    }

} 

This is the data source where I can retrieve all the days and their column values into a cursor to be used in a simplecursoradapter to be applied to a listview. I get this too.

DaysActivity.java:

package com.dd.gfit;

import android.app.ListActivity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.widget.SimpleCursorAdapter;

public class DaysActivity extends ListActivity {

    private DaysDataSource datasource;
    private SimpleCursorAdapter dataAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {       
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_days);

        datasource = new DaysDataSource(this);
        datasource.open();

        Cursor cursor = datasource.fetchAllDays(routineDataID);
        String[] columns = new String[] { MySQLiteHelper.COLUMN_NAME, MySQLiteHelper.COLUMN_DAY };
        int[] to = new int[] { R.id.listitem_day_name, R.id.listitem_day_day };
        dataAdapter = new SimpleCursorAdapter(this, R.layout.listitem_day, cursor, columns, to, 0);
        setListAdapter(dataAdapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {     
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.activity_days, menu);
        return true;        
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long thisID)
    {
        Day day = (Day)getListAdapter().getItem(position);
        long id = day.getId();

        Intent startDayActivity = new Intent(this, DayActivity.class);
        startDayActivity.putExtra("routineDataID", id);
        this.startActivity(startDayActivity);
    }

} 

This is the part I don’t get. First of all the listview shows up perfect with what I want in it. The onListItemClick() function is causing the app to crash when it is fired (when I click a list item). id seems to be coming up null or something? It’s like it was never assigned a value for the list item.

I need to know what I am missing here. I need someone to help me and tell me what I need to add to my code and where to add it so I can better understand how to do this properly in the future.

I’m assuming I need to have the values for the day applied BEFORE trying to use the getId() function? Any help would be great.

EDIT:

I have a button inside the listview, I also want to be able to grab the id when this button is clicked.

Heres the code using an array adapter that I would like to convert to a simplecursoradapter:

public void onClick(View view) {    
    @SuppressWarnings("unchecked")
    ArrayAdapter<Day> adapter = (ArrayAdapter<Day>)getListAdapter();
    ListView lv = getListView();
    int position = lv.getPositionForView(view);
    Day day = (Day) getListAdapter().getItem(position);
    long id = day.getId();
}

EDIT AGAIN:

Figured it out. Heres the code:

    ListView l = getListView();
    int position = l.getPositionForView(view);

    Cursor cursor = ((SimpleCursorAdapter)l.getAdapter()).getCursor();
    cursor.moveToPosition(position);
    long id = cursor.getLong(cursor.getColumnIndex(MySQLiteHelper.COLUMN_ID));
    String name = cursor.getString(cursor.getColumnIndex(MySQLiteHelper.COLUMN_NAME));

Answer 1

Change your onListItemClick code as for getting selected value from Cursor:

@Override
    protected void onListItemClick(ListView l, View v, int position, long thisID)
    {
      Cursor cursor = ((SimpleCursorAdapter)l.getAdapter()).getCursor();
      cursor.moveToPosition(position);
      long id = cursor.getLong(cursor.getColumnIndex("YOUR_COLUMN_NAME_HERE"));

      Intent startDayActivity = new Intent(DaysActivity.this, DayActivity.class);
      startDayActivity.putExtra("routineDataID", id);
      startActivity(startDayActivity);
    }