activity onPause how to save the interface data

Question

Hello I have in my app 2 activities and I want that when I switch between them the user interface and the Variables wont change is there any way to do it.

Thanks for the help

Answer 1

If you want to save primitive data type (string,int,boolean etc.. ) use SharedPreferences, that will save your values permanently, untill user reinstall (clear data) application. Shared Preferences works like this

// save string in sharedPreferences
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                    SharedPreferences.Editor editor = settings.edit();
                    editor.putString("some_key", string); // here string is the value you want to save
                    editor.commit(); 

// restore string in sharedPreferences

SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
string = settings.getString("some_key", "");

Answer 2

SharedPreferences seem like the simplest way for you to achieve it, as you can use the SharedPreferences methods to save anything (well, any basic datatype) persistently.

/**
 * Retrieves data from sharedpreferences
 * @param c the application context
 * @param pref the preference to be retrieved
 * @return the stored JSON-formatted String containing the data 
 */
public static String getStoredJSONData(Context c, String pref) {
    if (c != null) {
        SharedPreferences sPrefs = c.getSharedPreferences("AppPreferences", Context.MODE_PRIVATE);
        return sPrefs.getString(pref, null);
    }
    return null;
}

/**
* Stores the most recent data into sharedpreferences
* @param c the application context
* @param pref the preference to be stored
* @param policyData the data to be stored
*/
public static void setStoredJSONData(Context c, String pref, String policyData) {
    if (c != null) {
        SharedPreferences sPrefs = c.getSharedPreferences("AppPreferences", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sPrefs.edit();
        editor.putString(pref, policyData);
        editor.commit();
    }
}

Where the string 'pref' is a tag used to refer to that specific piece of data, so for example: "taylor.matt.data1" would refer to a piece of data and could be used to retrieve or store it from SharedPreferences.