Android - add values to String[] through another class

Question

I have a problem in adding values to my String[] array from another class. What I wanted to do is to add values to my MainScreenEntered.java class from database through my MyDatabaseAdapter.java class.

PLease help.

THis is my code.

MainScreenentered.java

public class MainScreenEntered extends Activity implements OnItemClickListener{
 @SuppressLint("NewApi")
 ListView lv;
 List<RowItem> rowItems;
 MyDatabaseAdapter mh;
 String username;
 ListView listViewSMS;
 Cursor cursor;
 Context context;
 public static String[] names = new String[] {};
 public static String[] descriptions = new String[] {};
 public static String[] pics = new String[] {};
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main_screen_entered);
 mh = new MyDatabaseAdapter(this);
 Bundle bundle = this.getIntent().getExtras();
 username = bundle.getString("username");
 Message.message(this, username);
 try
 {
 mh.getDataToDatabase();
 rowItems = new ArrayList<RowItem>();
 for(int i =0; i< names.length; i++)
 {
 RowItem item = new RowItem(pics[i], names[i], descriptions[i]);
 rowItems.add(item);
 }
 lv = (ListView)findViewById(R.id.lvEntries);
 CustomListViewAdapter adapter = new CustomListViewAdapter(this, R.layout.list_layout,rowItems);
 lv.setAdapter(adapter);
 lv.setOnItemClickListener(this);
 }
 catch(Exception e)
 {
 Message.message(this, ""+e);
 }
 }
}

MyDatabaseAdapter.java

public class MyDatabaseAdapter {
 MyHelper helper;
 public MyDatabaseAdapter (Context context)
 {
 helper = new MyHelper(context);
 }
 public void getDataToDatabase()
 {
 MainScreenEntered ms = new MainScreenEntered();
 SQLiteDatabase db = helper.getWritableDatabase();
 String columns[] = {MyHelper.ENTRY_FULLNAME,MyHelper.ENTRY_DESCRIPTION,MyHelper.ENTRY_IMAGE};
 Cursor c=db.query(MyHelper.TABLE_ENTRIES, columns, null, null, null, null, null);
 int i=0;
 while(c.moveToNext())
 {
 String name = c.getString(0); 
 String desc = c.getString(1); 
 String pic = c.getString(2); 
 ms.names[i] = name;
 ms.descriptions[i] = desc;
 ms.pics[i] = pic;
 i++;
 }
 db.close();
 }
}

• Mark Pazon: What is the actual "problem"? Are you getting an error?

Answer 1

you can do like this

in onCreate
mh = new MyDatabaseAdapter(this,this);

now

public class MyDatabaseAdapter {
MyHelper helper;
MainScreenEntered ms;
public MyDatabaseAdapter (Context context, MainScreenEntered ms)
{
 helper = new MyHelper(context);
 this.ms = ms;
}
public void getDataToDatabase()
{
 SQLiteDatabase db = helper.getWritableDatabase();
 String columns[] = {MyHelper.ENTRY_FULLNAME,MyHelper.ENTRY_DESCRIPTION,MyHelper.ENTRY_IMAGE};
 Cursor c=db.query(MyHelper.TABLE_ENTRIES, columns, null, null, null, null, null);
 int i=0;
 while(c.moveToNext())
 {
 String name = c.getString(0); 
 String desc = c.getString(1); 
 String pic = c.getString(2); 
 ms.names[i] = name;
 ms.descriptions[i] = desc;
 ms.pics[i] = pic;
 i++;
 }
 db.close();
 }
}

Answer 2

Try this..

In your MainScreenEntered.java

public static ArrayList<String> names = new ArrayList<String>();
public static ArrayList<String> descriptions = new ArrayList<String>();
public static ArrayList<String> pics = new ArrayList<String>();

and MyDatabaseAdapter

while(c.moveToNext())
{
 String name = c.getString(0); 
 String desc = c.getString(1); 
 String pic = c.getString(2); 
 MainScreenEntered.names.add(name);
 MainScreenEntered.descriptions.add(desc);
 MainScreenEntered.pics.add(pic);
}

then

 rowItems = new ArrayList<RowItem>();
 for(int i =0; i<names.length; i++)
 {
 RowItem item = new RowItem(pics.get(i), names.get(i), descriptions.get(i));
 rowItems.add(item);
 }

Answer 3

use c.movetoFirst() before while loop and for static array u doesn't have to create object of it u can directly call it ClassName.variable_name ... it will be a better if you use arraylist of string rather than string array.

Answer 4

Be careful by doing DB operation on the UI thread you will might have some ANR.