How to send SharedPreferences from one Activity to another

Question

I am trying to adapt this code http://automateddeveloper.blogspot.co.uk/2011/06/getting-started-complete-android-app.html for my quiz game. I have downloaded http://sourceforge.net/projects/sqlitebrowser/ as suggested in the comment section of the link above. I have my own db running on my device and I am using Eclipse and targeting Android 4. All works. What I cannot get to work is the SettingsActivity even though in my new db I have changed the difficulty ratings and made sure there are Easy, Medium and Hard.

When I leave the Settings on "Medium" difficulty the quiz game goes off without a hitch. When I change the Settings to "Easy" and then go back to menu and click play the game tells me it is stopping.

I am posting what I feel are the relevant code. I have not been able to find anything other than what is posted in the comment section of the link.

The SplashActivity:

private List<Question> getQuestionSetFromDb() throws Error {
        int diff = getDifficultySettings();
        Syste`enter code here`m.out.print("diff" + diff);
        //Log("diff" + diff);
        int numQuestions = getNumQuestions();
        DBHelper myDbHelper = new DBHelper(this);
        try {
            myDbHelper.createDataBase();
        } catch (IOException ioe) {
            throw new Error("Unable to create database");
        }
        try {
            myDbHelper.openDataBase();
        }catch(SQLException sqle){
            throw sqle;
        }
        List<Question> questions = myDbHelper.getQuestionSet(diff, numQuestions);
        myDbHelper.close();
        return questions;
    }

/**
     * Method to return the difficulty settings
     * @return
     */
    private int getDifficultySettings() {
        SharedPreferences settings = getSharedPreferences(Constants.SETTINGS, 0);
        int diff = settings.getInt(Constants.DIFFICULTY, Constants.EASY);
        return diff;
    }

The SettingsActivity:

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

        /**
         * set listener on update button
         */
        Button updateBtn = (Button) findViewById(R.id.nextBtn);
        updateBtn.setOnClickListener(this);

        /**
         * Set selected button if saved
         */
        updateButtonWithPreferences();

    }


    /**
     * Method to update default check box
     */
    private void updateButtonWithPreferences() {
        RadioButton c1 = (RadioButton)findViewById(R.id.easySetting);
        RadioButton c2 = (RadioButton)findViewById(R.id.mediumSetting);
        RadioButton c3 = (RadioButton)findViewById(R.id.hardSetting);

        SharedPreferences settings = getSharedPreferences(Constants.SETTINGS, 0);
        int diff = settings.getInt(Constants.DIFFICULTY, Constants.MEDIUM);

        switch (diff)
        {
        case Constants.EASY : 
            c1.toggle();
            break;

        case Constants.MEDIUM : 
            c2.toggle();
            break;

        case Constants.EXTREME :
            c3.toggle();
            break;  
        }
    }





    @Override
    public void onClick(View arg0) {
        /**
         * check which settings set and return to menu
         */
        if (!checkSelected())
        {
            return;
        }
        else
        {
            SharedPreferences settings = getSharedPreferences(Constants.SETTINGS, 0);
            Editor e = settings.edit();
            e.putInt(Constants.DIFFICULTY, getSelectedSetting());
            e.commit();
            finish();
        }

    }


    /**
     * Method to check that a checkbox is selected
     * 
     * @return boolean
     */
    private boolean checkSelected() {
        RadioButton c1 = (RadioButton)findViewById(R.id.easySetting);
        RadioButton c2 = (RadioButton)findViewById(R.id.mediumSetting);
        RadioButton c3 = (RadioButton)findViewById(R.id.hardSetting);
        return (c1.isChecked() || c2.isChecked() || c3.isChecked());
    }


    /**
     * Get the selected setting 
     */
    private int getSelectedSetting() {
        RadioButton c1 = (RadioButton)findViewById(R.id.easySetting);
        RadioButton c2 = (RadioButton)findViewById(R.id.mediumSetting);
        if (c1.isChecked())
        {
            return Constants.EASY;
        }
        if (c2.isChecked())
        {
            return Constants.MEDIUM;
        }

        return Constants.EXTREME;
    }

}

The rest of the code works fine include the new questions that I put into the db so I will keep the code posting at this unless someone request anything more.

Thanks a lot in advance, Terry

Answer 1

Use this to use application scope shared preferences:

SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(Context context)

In place of: SharedPreferences settings = getSharedPreferences(Constants.SETTINGS, 0);