Develop Reference

Getting an array from SharedPreferences

I am trying to save different arrays of information related to movies that are added to SharedPreferences when the user presses the favorite star, like a favorite movie list, then I'll use that list to sort a movie poster listview display screen.
Preferences variable:
preferences = getContext().getSharedPreferences("favorites_list", Context.MODE_PRIVATE);
Here is where I add the movie (or remove) to the list when the user presses the favorite button:
ib = (ImageButton) rootView.findViewById(R.id.favorite);
ib.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(!favoriteState) {
ib.setBackgroundResource(R.drawable.starpressed);
favoriteState = true;
SharedPreferences.Editor preferencesEditor = preferences.edit();
preferencesEditor.putStringSet(movieInfo[1], new HashSet<String>(Arrays.asList(movieInfo)));
preferencesEditor.commit();
}else{
ib.setBackgroundResource(R.drawable.star);
favoriteState = false;
SharedPreferences.Editor preferencesEditor = preferences.edit();
preferencesEditor.remove(movieInfo[1]);
preferencesEditor.commit();
}
}
});
Here is where I want to get the array from SharedPreferences, but I want to get everything there not only some array based on the keyValue that I set.
Here is where I want to fetch all data in the favorites_list inside SharedPreferences:
private void updateMovies() {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
String preference = prefs.getString(getString(R.string.pref_sortby_key), getString(R.string.pref_sortby_default));
if(preference.toLowerCase().equals("favorites")){
SharedPreferences preferences = getContext().getSharedPreferences("favorites_list", Context.MODE_PRIVATE);
}else{
new FetchMoviesTask().execute(baseUrl+preference.toLowerCase()+apiKey, "i");
}
}
I am not sure if I inserted them correctly, and is there a way to check on androidStudio?
Thank you in advance for your help.

Save SWITCH button state, and recover state with SharedPrefs

I have a Settings class so the user can decide to subscribe/unsubscribe to channels in Parse Push.
I think I got it all figure out except for the part to recover, and maintain the switch state next time user open the app or changes the state.
Can someone please help me on how to save the state, and switch the SWITCH to what the user selected?
public class Settings extends Activity {
/**
* Called when the activity is first created.
*/
private Switch krspush, egspush;
public static final String PREFS_NAME = "SwitchButton";
krspush = (Switch) findViewById(R.id.krspush);
egspush = (Switch) findViewById(R.id.egspush);
SharedPreferences sharedPrefs = getSharedPreferences("SwitchButton", MODE_PRIVATE);
// How?
public void onKrsClick (View view) {
boolean on = ((Switch) view).isChecked();
if (on) {
SharedPreferences.Editor editor = getSharedPreferences("SwitchButton", MODE_PRIVATE).edit();
editor.putBoolean("onKrsClick", true);
editor.commit();
ParsePush.subscribeInBackground("egersund");
} else {
SharedPreferences.Editor editor = getSharedPreferences("SwitchButton", MODE_PRIVATE).edit();
editor.putBoolean("onKrsClick", false);
editor.commit();
ParsePush.unsubscribeInBackground("egersund");
}
}
public void onEgsClick (View view) {
boolean on = ((Switch) view).isChecked();
if (on) {
SharedPreferences.Editor editor = getSharedPreferences("SwitchButton", MODE_PRIVATE).edit();
editor.putBoolean("onEgsClick", true);
editor.commit();
ParsePush.subscribeInBackground("egersund");
} else {
SharedPreferences.Editor editor = getSharedPreferences("SwitchButton", MODE_PRIVATE).edit();
editor.putBoolean("onEgsClick", false);
editor.commit();
ParsePush.unsubscribeInBackground("egersund");
}
}

Override the onCreate method of that activity class and attempt to load the values you saved in SharedPreferences.
krspush.setChecked(sharedPrefs.getBoolean("onKrsClick",false));

findviewbyid will crash unless called after the view is created ie, in the oncreate method.
Consider using click listener on your switches.
I don't see the point of this line of code "SharedPreferences sharedPrefs = getSharedPreferences("SwitchButton", MODE_PRIVATE)"
Here is how you use shared preferences : https://stackoverflow.com/a/23024962/2590252
You better look into some samples to learn about best coding practices http://developer.android.com/samples/index.html

Saving checkbox state using SharedPreferences

how do i save a checkbox state in activity B so that when i go back to activity A , it will show an appropriate response?
I am trying to make a function such that when a checkbox state in Activity B is checked , it will go back to A and play music , and this preference will be saved so that when the app is killed and relaunched , the preference stays.

You can save a boolean in SharedPreferences. It's clearly explained here: http://developer.android.com/training/basics/data-storage/shared-preferences.html

On Activity B you need to set preference depends on the CheckBox state
checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
SharedPreferences sharedPref = getBaseContext().getSharedPreferences("mypref", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putBoolean("checked", isChecked);
editor.commit();
}
});
On Activity A you need to get the preference value as follow
SharedPreferences sharedPref = context.getSharedPreferences("mypref", Context.MODE_PRIVATE);
boolean isChecked = sharedPref.getBoolean("checked", false); // false if it's not exist

Implement OnSharedPreferenceChangeListener in your activity B and override onSharedPreferenceChanged method
Here's my code
#Override
public void onSharedPreferenceChanged(SharedPreferences preferences,String arg1) {
// TODO Auto-generated method stub
preferences = PreferenceManager.getDefaultSharedPreferences(this);
checkbox = preferences.getBoolean("checkbox", false);
if(checkbox){
//Do your stuff here like playing music
Log.d("checkbox", "check enabled");
Intent myIntent = new Intent(ActivityB.this, ActivityA.class);
startActivity(myIntent);
}

Delete data from shared preferences in android

I am trying to delete the data from shared preferences. But I cant do that. To track that the data is removed or not, I am using this code:
btnLogout.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
SharedPreferences prefs = getSharedPreferences(share_pref_file, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.remove(share_pref_file);
editor.clear();
editor.commit();
getApplicationContext().getSharedPreferences(share_pref_file, 0).edit().clear().commit();
String strJson = prefs.getString("jsondata","");
if(strJson != null)
{
Log.d("CLEAR", "cccccccccccccccccccccccccccc");
}
userFunctions.logoutUser(getApplicationContext());
Intent login = new Intent(getApplicationContext(),LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
// Closing dashboard screen
finish();
}
});
But in logcat window it is showing me "cccccccccccccccccccccccccccc" value every time.
So can anyone help me out that how to remove/delete the data from shared preferences so that if I click on 'logout' button it will remove all the stored data? Thanks in advance.

An empty string is still a string (and String("") != null will return true). Try this instead:
if(!strJson.equals(""))
This assumes the empty string will never be a valid input in your SharedPreferences in the first place.

Try this one inside the button click event to clear the SharedPreferences values.
Editor editor = getSharedPreferences("MyPref", Context.MODE_PRIVATE).edit();
editor.clear();
editor.commit();

Try editor.clear(); followed by a editor.commit();
Here is one example that I've used:
Preference clearPref = (Preference) findPreference("MyPref");
btnLogout.setOnPreferenceClickListener(new OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
SharedPreferences.Editor editor = settings.edit();
editor.clear();
editor.commit();
Toast.makeText(getBaseContext(), "All data cleared!", Toast.LENGTH_SHORT).show();
return true;
}
});

Either change this:
String strJson = prefs.getString("jsondata", "");
To:
String strJson = prefs.getString("jsondata", null);
And then check:
if(strJson != null) {
Log.d("CLEAR", "cccccccccccccccccccccccccccc");
}
Or keep it as it is and check it like this:
if(strJson.equals("")) {
Log.d("CLEAR", "cccccccccccccccccccccccccccc");
}

settings.edit().clear().commit();
is a one line code I am using, works perfectly

It is my solution:
You can put null instead of your favorite data in shareprefrences
getApplicationContext();
SharedPreferences.Editor pref = (Editor) getSharedPreferences("data", MODE_PRIVATE).edit();
pref.putString("admin_no", null);
pref.commit();

how to reset all stored data store using shared preferences

I have created an activity where i have used shared preferences for storing data..now in another activity i have an reset button..when i click on the reset button the data store will be lost..so how that can be done..my code is
code in activity1:
public void writeToRegister()
{
// Write history data to register
SharedPreferences preferences1 = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor1 = preferences1.edit();
editor1.putInt("iHistcount", CycleManager.getSingletonObject().iHistCount);
for(int i=0;i< CycleManager.getSingletonObject().iHistCount;i++)
{
editor1.putLong("dtHistoryDate"+Integer.toString(i), CycleManager.getSingletonObject().dtHistory[i].getTime());
}
editor1.commit();
}
public void readFromRegister()
{
// Read history data from register
SharedPreferences preferences1 = getPreferences(MODE_PRIVATE);
CycleManager.getSingletonObject().iHistCount=preferences1.getInt("iHistcount", 0);
for(int i=0;i< CycleManager.getSingletonObject().iHistCount;i++)
{
Long x=preferences1.getLong("dtHistoryDate"+Integer.toString(i), 0L);
CycleManager.getSingletonObject().dtHistory[i]=new Date(x);
}
}
code for Activity 2:
Button pBtnReset = new Button(this);
pBtnNextMonth.setOnClickListener(pBtnReset OnClickListener);
Button.OnClickListener pBtnReset OnClickListenernew Button.OnClickListener()
{
public void onClick(View arg0)
{
}
};
so what i have to write in second activity reset button so that it clear the stored data

Get your Editor and call clear() something like this:
Edit: as the user DDoSAttack mentioned.
There are two ways of getting SharedPreferences
1: getting default SharedPreferences
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(con);
2: getting specific SharedPreferences
SharedPreferences prefs = Context.getSharedPreferences("FileName", Context.MODE_PRIVATE);
and here is how you'll clear it.
public void clear()
{
SharedPreferences prefs; // here you get your prefrences by either of two methods
Editor editor = prefs.edit();
editor.clear();
editor.commit();
}

its very easy..
yourEditor.remove(" thing you want to remove on start");
and then give must
yourEditor.commit();

If you want to wipe all the data in a preference file call clear() from the SharedPreferences.Editor instance
http://developer.android.com/reference/android/content/SharedPreferences.Editor.html#clear()

Use SharedPreferences.Editor clear() method.
See Documentation
SharedPreferences preferences = getPreferences(0);
SharedPreferences.Editor editor = preferences.edit();
editor.clear();
editor.commit();