delete DB

[ndrokki]

Ciao sono bloccato su un comando lanciato da un context menu, che dovrebbe cancellare la riga nel database e ricaricare le righe in list view.

questa e' la classe con il context menu comando delete(accorciata che non entrava)

     @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 123) {
            String string = data.getExtras().getString(getActivity().getPackageName());
            Log.d("FragmentAsList", "stringa dall altra activity: " + string);
            Toast.makeText(getActivity(), string, Toast.LENGTH_LONG).show();
            ///database insert
            today.setToNow();
            String timeCurrent = today.format("%Y-%m-%d %H:%M:%S");
            myDb.insertRow(string, timeCurrent, null, null);
            //database query
            Cursor cursor = myDb.getallRows();
            String[] fromFieldNames = new String[]{Db.ROW_TASK};
            int[] toViewId = new int[]{R.id.text_row};


            SimpleCursorAdapter myCursorAdapter;
            myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
            listView.setAdapter(myCursorAdapter);



        }
    }

     @Override
    public View onCreateView(LayoutInflater inflater,  @nullable ViewGroup container,  @nullable Bundle savedInstanceState) {



        View hiddenList = inflater.inflate(R.layout.fragment_as_list, container, false);

        
        //We are inside a fragment, we have to speak with the compiler !
        registerForContextMenu(listView);
        Cursor cursor = myDb.getallRows();
        String[] fromFieldNames = new String[]{Db.ROW_TASK};
        int[] toViewId = new int[]{R.id.text_row};


        SimpleCursorAdapter myCursorAdapter;
        myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
        listView.setAdapter(myCursorAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Log.d("ivano.android.com.ucanote.FragmentAsList", "onItemClick (line 115): tocca posizione: " + position);
                //TODO make a new activity where you have a causal motivational thing etc

//        Intent explicitIntent =new Intent(getActivity(),DetailNote.class);
//        startActivity(explicitIntent);
            }

        });


        return hiddenList;







    }
     @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {

        super.onCreateContextMenu(menu, v, menuInfo);

        MenuInflater mi = getActivity().getMenuInflater();


        mi.inflate(R.menu.context_menu, menu);
    }

     @Override
    public boolean onContextItemSelected(MenuItem item) {

        Log.d("ivano.android.com.ucanote.FragmentAsList", "onContextItemSelected (line 148): toccato");
        switch (item.getItemId()) {
            case R.id.delete:
                //TODO delete
                registerForContextMenu(listView);
                AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
                long index = info.position;
                Log.d("ivano.android.com.ucanote.FragmentAsList", "onContextItemSelected (line 160): the position is " + index);
                //TODO first content provider

                myDb.deleteRow(index);

                Cursor cursor = myDb.getallRows();
                String[] fromFieldNames = new String[]{Db.ROW_TASK};
                int[] toViewId = new int[]{R.id.text_row};


                SimpleCursorAdapter myCursorAdapter;
                myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
                listView.setAdapter(myCursorAdapter);



                break;
            case R.id.edit:
                break;
            case R.id.share:
                break;

        }

        return super.onContextItemSelected(item);
    }

}

e questo il database su cui viene eseguito il comando delete row e dopo getallrows

package ivano.android.com.ucanote.ivano.android.com.ucanote.db;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * Created by ivano on 4/8/2015.
 */
public class Db {
    private static final String TAG="Db";
//TODO check if all the fields are used,
// expecially TAG, ALL KEYS and columns, and what is the function of DB info?

    //fields
    public static final String ROW_ID = "_id";
    public static final String ROW_TASK = "task";
    public static final String ROW_DATE = "date";
    public static final String ROW_URGENCY = "urgency";
    public static final String ROW_TAG= "tag";

    public static final String[] ALL_ROWS=new String[]{ROW_ID,ROW_TASK,ROW_DATE,ROW_URGENCY,ROW_TAG};

    //Columns
    public static final int COL_ID = 0;
    public static final int COL_TASK = 1;
    public static final int COL_DATE = 2;
    public static final int COL_URGENCy = 3;
    public static final int COL_TAG=4;

    //DB info
    public static final String DATABASE_NAME = "db";
    public static final String DATABASE_TABLE="table1";

    //always remember to change this if I are going to update the DB!
    public static final int    DATABASE_VERSION=1;

    //create

    private static final String DATABASE_CREATE_SQL=
            "CREATE TABLE " + DATABASE_TABLE
            + " ("  + ROW_ID+ " INTEGER PRIMARY KEY AUTOINCREMENT, "
            +ROW_TASK+ " TEXT NOT NULL, "
            +ROW_DATE+ " TEXT, "
            +ROW_URGENCY+" TEXT, "
            +ROW_TAG+" TEXT " +
                    " );";


private final Context context;
    private DatabaseHelper myDBHelper;
    private SQLiteDatabase db;

public Db (Context ctx) {
    this.context = ctx;
    myDBHelper=new DatabaseHelper(context);
    }

    public Db open() {
    db= myDBHelper.getWritableDatabase();
        return this;
    }

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

    public long insertRow (String task,String date, String urgency, String tag) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(ROW_TASK, task);
        initialValues.put(ROW_DATE, date);
        initialValues.put(ROW_URGENCY, urgency);
        initialValues.put(ROW_TAG, tag);

    return db.insert(DATABASE_TABLE,null,initialValues);
    }
        //delete a row from the db by _id
        public boolean deleteRow(long rowId) {
            String where =ROW_ID+"="+ rowId;

            return db.delete(DATABASE_TABLE,where,null) != 0;


}
    public void deleteAll(){
        Cursor c=getallRows();
        long rowId=c.getColumnIndex(ROW_ID);
        if (c.moveToFirst()) {
            do {
                deleteRow(c.getLong((int) rowId));

            }
            while (c.moveToNext());
        }
            c.close();

    }
    public Cursor getallRows(){
        String where=null;
        Cursor c=db.query(true,DATABASE_TABLE,ALL_ROWS,where,null,null,null,null,null);
   if (c!= null){
c.moveToFirst();
    }
      return c;


    }
public Cursor getRow(long rowId){
    String where =ROW_ID+"=" +rowId;
    Cursor c=db.query(true,DATABASE_TABLE,ALL_ROWS,where,null,null,null,null,null);
    if(c!= null){
        c.moveToFirst();
    }
    return c;

}
    public boolean updateRow(long rowId,String task,String date, String urgency,String tag){
        String where =ROW_ID+"="+rowId;
        ContentValues newValues =new ContentValues();
        newValues.put(ROW_TASK,task);

        newValues.put(ROW_DATE, date);
        newValues.put(ROW_URGENCY, urgency);
        newValues.put(ROW_TAG, tag);
        return db.update(DATABASE_TABLE,newValues,where,null)!=0;

    }

    private static class DatabaseHelper extends SQLiteOpenHelper{
        DatabaseHelper(Context context){
            super (context,DATABASE_NAME,null,DATABASE_VERSION);

        }

         @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(DATABASE_CREATE_SQL);

        }

         @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG,"Upgrading application's database from version"
                    +oldVersion+ " to "+newVersion+
                    " ,which will destroy all the old data!");
            db.execSQL("DROP TABLE IF EXISTS "+DATABASE_TABLE);
            onCreate(db);
        }
    }
}