Question

I am building an application in which I’m populating data from the database into the listview of my activity. Now, on longItemClick Listener I want to delete that value from the database and update my listview in the app.

Here my code for longClickListener on the listview:

private ListView showing_history;
private ListAdapter mHistoryListAdapter;
private ArrayList<SearchHistoryDetails> searchArrayList;
private ArrayList<SearchHistoryDetails> HistoryObjArrayList;


    mHistoryListAdapter = new ArrayAdapter<String>(this,
            R.layout.mylistlayout, populateList());
    showing_history.setAdapter(mHistoryListAdapter);
    HistoryObjArrayList = new ArrayList<SearchHistoryDetails>();

/**
     * Long tap on listview to delete the selected item from the history
     * list.
     * */
    showing_history
            .setOnItemLongClickListener(new OnItemLongClickListener() {

                @Override
                public boolean onItemLongClick(AdapterView<?> arg0,
                        View arg1, int arg2, long arg3) {
                    final AlertDialog.Builder b = new AlertDialog.Builder(
                            MainActivity.this);
                    b.setIcon(android.R.drawable.ic_dialog_alert);
                    b.setMessage("Delete this from history?");
                    b.setPositiveButton("Yes",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int whichButton) {
                                    Toast.makeText(getApplicationContext(),
                                            "Yes", Toast.LENGTH_LONG)
                                            .show();
                                }
                            });
                    b.setNegativeButton("No",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int whichButton) {
                                    dialog.cancel();
                                }
                            });

                    b.show();
                    return true;
                }
            });

By this code I’m inserting data into the database:

/**
 * Inserting the string when user searches for anything into the database.
 * */
public void insertHistory(SearchHistoryDetails paraHistoryDetailsPojoObj) {

    AndroidOpenDbHelper androidOpenDbHelperObj = new AndroidOpenDbHelper(
            this);

    SQLiteDatabase sqliteDatabase = androidOpenDbHelperObj
            .getWritableDatabase();

    ContentValues contentValues = new ContentValues();

    contentValues.put(AndroidOpenDbHelper.COLUMN_NAME_HISTORY_STRING,
            paraHistoryDetailsPojoObj.getHistoryName());
    @SuppressWarnings("unused")
    long affectedColumnId = sqliteDatabase.insert(
            AndroidOpenDbHelper.TABLE_NAME_HISTORY, null, contentValues);

    sqliteDatabase.close();

}

Here is the code from which I’m retrieving data from the database and repopulating it into the list view:

public List<String> populateList() {

    List<String> HistoryNamesList = new ArrayList<String>();

    AndroidOpenDbHelper openHelperClass = new AndroidOpenDbHelper(this);

    SQLiteDatabase sqliteDatabase = openHelperClass.getReadableDatabase();

    Cursor cursor = sqliteDatabase
            .query(AndroidOpenDbHelper.TABLE_NAME_HISTORY,
                    new String[] { AndroidOpenDbHelper.COLUMN_NAME_HISTORY_STRING },
                    null, null, null, null, AndroidOpenDbHelper.ID
                            + " DESC");

    startManagingCursor(cursor);

    while (cursor.moveToNext()) {
        String ugName = cursor
                .getString(cursor
                        .getColumnIndex(AndroidOpenDbHelper.COLUMN_NAME_HISTORY_STRING));

        SearchHistoryDetails histPojoClass = new SearchHistoryDetails();
        histPojoClass.setHistoryName(ugName);

        searchArrayList.add(histPojoClass);

        HistoryNamesList.add(ugName);
    }

    sqliteDatabase.close();

    int history_db = cursor.getCount();

    if (history_db == 0) {
        history_layout.setVisibility(LinearLayout.GONE);
    } else {
        history_layout.setVisibility(LinearLayout.VISIBLE);
    }

    return HistoryNamesList;
}

Retrieving and inserting data all things are perfectly, but deleting of a particular row is not working for me. Right now I have done some action using toast and it is working, what should I do so that, the database data updates after deletion of the row from the listview. Please give me any idea to overcome this problem.

Answer 1

Try this..,.

b.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
  public void onClick(DialogInterface dialog, int whichButton) {
            DatabaseHandler db=new DatabaseHandler(getApplicationContext());
            db.delete(arg3+"");
            list.remove(position);
            YourActivity.this.adapter.notifyDataSetChanged();
  }
});

and in DatabaseHandler class

public void delete(String id)
{
    SQLiteDatabase db = this.getReadableDatabase();
    db.delete(TABLE_NAME, KEY_ID + "=?", new String[]{id});
    db.close();
}