I know, this issue has been dealt with in many threads, but I cannot figure out this one.
So I set a shared preference like this:
SharedPreferences prefs = MainActivity.this.getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putStringSet(spinnerName, myValueSet );
editor.apply();
I read the preferences like this:
SharedPreferences prefs = MainActivity.this.getPreferences(MODE_PRIVATE);
Set<String> spinnerValuesSet = null;
spinnerValuesSet = prefs.getStringSet(spinnerName,null );
Everything works, except for my changes are visible while this activity runs i.e. - I display the values from the SharedPreferences, allow the user to delete or add and then update the ListView. This works, but after I restart the application, I get the initial values.
This for example is my method to delete one value from the list, update the values in SharedPreferences and update the ListView
Button btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
SharedPreferences prefs = MainActivity.this.getPreferences(MODE_PRIVATE);
Set<String> spinnerValuesSet = prefs.getStringSet(spinnerName,null );
for (String s : spinnerValuesSet)
{
if(s == currentSelectedItemString)
{
spinnerValuesSet.remove(s);
SharedPreferences.Editor editor = prefs.edit();
editor.putStringSet(spinnerName, spinnerValuesSet );
editor.apply();
break;
}
}
updateListValues();
}
});
And this is the method that updates the ListView:
private void updateListValues()
{
SharedPreferences prefs = MainActivity.this.getPreferences(MODE_PRIVATE);
Set<String> spinnerValuesSet = prefs.getStringSet(spinnerName,null );
if(spinnerValuesSet.size() > 0)
{
names = new ArrayList<String>();
names.clear();
int k=0;
for (String s : spinnerValuesSet) {
names.add(k, s);
k++;
}
namesAA = new ArrayAdapter<String> ( this, android.R.layout.simple_list_item_activated_1, names );
myList.setAdapter(namesAA);
}
}
Any help is much appreciated.
The Objects returned by the various get methods of SharedPreferences should be treated as immutable. See SharedPreferences Class Overview for reference.
You must call remove(String) through the SharedPreferences.Editor returned by SharedPreferences.edit() rather than directly on the Set returned by SharedPreferences.getStringSet(String, Set<String>).
You will need to construct a new Set of Strings containing the updated content each time since you have to remove the Set entry from SharedPreferences when you want to update its content.
Problem happens because the Set returned by SharedPreference is immutable. https://code.google.com/p/android/issues/detail?id=27801
I solved this by created a new instance of Set and storing in all the values returned from SharedPreferences.
//Set<String> address_ids = ids from Shared Preferences...
//Create a new instance and store everything there.
Set<String> all_address_ids = new HashSet<String>();
all_address_ids.addAll(address_ids);
Now use the new instance to push the update back to SharedPreferences
I may be wrong but I think the way you are retrieving the Shared Preferences is the problem. Try using
SharedPreferences prefs = getSharedPreferences("appPreferenceKey", Context.Mode_Private);
Use editor.commit(); instead of editor.apply();
Example Code:
SharedPreferences prefs = MainActivity.this.getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putStringSet(spinnerName, myValueSet );
editor.commit();
I hope this helps.
Depending on the OS Build you may have to save values in a different way.
boolean apply = Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD;
public static void saveValue(SharedPreferences.Editor editor)
{
if(apply) {
editor.apply();
} else {
editor.commit();
}
}
Related
I'm running to a really weird behavior with SharedPreferences. I'm wondering if I'm running into a synchronization issue.
It seems like the app can remember the preference changes in between activities but not when I restart the app. The state always returns back to the very first instance I created a preference. I've followed several examples, tutorials, and android documentation that all suggest similar code layout. I also watched how the preference.xml file changed while interacting with my code using the debugger and I confirmed it looked like the key value pair updated.
Could I be experiencing a synchronization issue with my emulator? I tried using both the editor.apply() method and editor.commit() method with the same results.
The only thing I've found that fixes my problem is using the editor.clear() method, but this feels a bit hacky...
note: please forgive the variable names, I'm making a pokedex...
public class SecondActivity extends AppCompatActivity {
private boolean caught;
private Set<String> pokemonCaught;
private String pokemonName;
public SharedPreferences sharedPreferences;
public static final String SHARED_PREFERENCES = "shared_preferences";
public static final String PREF_KEY = "inCaughtState";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
/*SKIPPING THE VIEW SETUP*/
/*SKIPPING BUTTON VIEW ATTRIBUTES*/
//variables required for changing button state
pokemonName = (String) nameTextView.getText();
caught = false;
//Loading in sharedPreferences
sharedPreferences =
getSharedPreferences(SHARED_PREFERENCES, Context.MODE_PRIVATE);
pokemonCaught = sharedPreferences.getStringSet(PREF_KEY, new HashSet<String>());
if (pokemonCaught.contains(pokemonName)) {
toggleCatch(catchButton);
}
}
public void toggleCatch (View view) {
//Editing and updating preferences
sharedPreferences =
getSharedPreferences(SHARED_PREFERENCES, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
if (caught == true) {
/*SKIPPING BUTTON ATTRIBUTES*/
caught = false;
pokemonCaught.remove(pokemonName);
}
else {
/*SKIPPING BUTTON ATTRIBUTES*/
caught = true;
pokemonCaught.add(pokemonName);
}
editor.clear(); //This is my hacky solution...
editor.putStringSet(PREF_KEY, pokemonCaught);
editor.apply();
}
}
Try to use SharedPreferences this way:
To save data
SharedPreferences.Editor editor = getSharedPreferences("PREFS", MODE_PRIVATE).edit();
editor.putString("stringName", "stringValue");
editor.apply();
To retrieve data
SharedPreferences preferences = getApplicationContext().getSharedPreferences("PREFS", MODE_PRIVATE);
String name = preferences.getString("stringName", "none"));
Note that this "none" is in case to string "stringName" be null.
and sorry if this is a stupid question. I'm learning to use SharedPreferences and I have a bit of a problem:
I'm using this code to save to SharedPreferences:
public void saveInMemory(String[] saveThis){
StringBuilder sb = new StringBuilder();
prefs = PreferenceManager.getDefaultSharedPreferences(OIBListActivity.this);
editor = prefs.edit();
for (int i = 0; i < saveThis.length; i++) {
sb.append(saveThis[i]);
sb.append(";");
}
editor.putString("listaOIB", sb.toString());
editor.commit();
}
And this code to load saved values:
public String loadFromMemory(String id){
prefs = PreferenceManager.getDefaultSharedPreferences(OIBListActivity.this);
return prefs.getString(id, "NOPREFSAVED");
}
I've also already declared prefs and editor outside, so that shouldnt be a problem:
private SharedPreferences prefs;
private SharedPreferences.Editor editor;
Now, my problem is that when I enter this activity and save files that i received from other activity(via putExtra, if that helps), then proceed to load it everything works fine.
Then I reenter my activity without sending any files to it (from other activity) and try to use loadFromMemory() and it doesnt work. My understanding is that it should have saved files when I entered Activity for the first time, and then load it whenever I want.
Any help?
add the method and call when you add and other is call when you get
//this method is call when you add the data
public static void setAlarmHourTime(String value, Activity activity) {
SharedPreferences.Editor pref = activity.getSharedPreferences("ALARMHOURTIME", Context.MODE_PRIVATE).edit();
pref.putString("alarmhourtime", value);
pref.commit();
}
//this method is call when you retrive the data
public static String getAlarmHourTime(Activity activity) {
SharedPreferences prefs = activity.getSharedPreferences("ALARMHOURTIME", Context.MODE_PRIVATE);
return prefs.getString("alarmhourtime","7");
}
if you want to retrieve content saved in editor.putString("listaOIB", sb.toString());, then the id you pass in loadFromMemory should be "listaOIB".
Is it the case?
Got this code, which basicly updates my textviews depending on how far the user is in the quiz, which is stored in sharedPrefs. But when the correct answer is entered the prefs doesn't update. Does the commit() need too long time to set the prefs, so the activity calls the method setText() before the sharedPrefs are updated or what am i doing wrong?
private void setText() {
SharedPreferences score = this.getSharedPreferences("football", MODE_PRIVATE);
questionNumber = score.getInt("football", 0);
question.setText(questions.get(questionNumber).get(0));
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.bCheckAnswer:
if (questions.get(questionNumber).contains(etAnswer.getText().toString())) {
Integer newQ = questionNumber += 1;
SharedPreferences change = this.getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = change.edit();
editor.putInt("football", newQ);
editor.commit();
setText();
}else{
question.setText("error occured");
}
break;
}
You're not opening the SharedPreference the same way when setting and getting.
Change this:
SharedPreferences change = this.getPreferences(Context.MODE_PRIVATE);
to this:
SharedPreferences change = this.getSharedPreferences("football", MODE_PRIVATE);
Notice the differences:
getPreferences vs getSharedPreferences
you didn't give the preference reference as "football"
Are you sure the prefs doesn't get updated or is it just that your textview isn't getting updated? If this is being done in your Activity, you should not be changing layout (your text view) from within the Activity. You should use a Handler to make UI changes.
I have made a program code for shared preference in android. But i am confused with sharedpreference. I am updating the sharedpreference if its not the same as earlier but every time i get the same value when i retrieve its value. Also please let me knw how to delete sharedpreference on onDestroy().
Bundle bundle = this.getIntent().getExtras();
resid=bundle.getString("locid");
SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
String prefresid = app_preferences.getString("preflocid", null);
Log.i("pref res id is",""+prefresid);
if(prefresid!=null)
{
if(resid.equalsIgnoreCase(prefresid))
{
Log.i("preference res id is the same","");
}
else
{
SharedPreferences.Editor e = PreferenceManager.getDefaultSharedPreferences(getBaseContext()).edit();
Log.i("preference res id is not same","creating new");
//SharedPreferences settings = getSharedPreferences("myfile", 0);
// SharedPreferences.Editor editor = settings.edit();
e.putString("preflocid",resid);
e.commit();
}
}
else
{
Log.i("new preference res id created",""+prefresid);
SharedPreferences.Editor editor = app_preferences.edit();
editor.putString("preflocid", resid);
editor.commit();
Log.i("new preference res id created","");
}
What you are doing in your code will only change the value of the preference once, namely the first time you read it. The first time it is null, which means you go into the else and save "locid" to "preflocid". The next time "locid" is set to and you will go into the if and then into the first if because "locid".equalsIgnoreCase(prefresid).
To remove preferences in onDestroy, just call this:
#Override
protected void onDestroy() {
SharedPreferences.Editor e = PreferenceManager.getDefaultSharedPreferences(getBaseContext()).edit();
e.clear();
e.commit();
}
Have just one object of default SharedPreference and have editor onto that like:
SharedPreferences s_pref= PreferenceManager.getDefaultSharedPreferences(context);
Editor edit=s_pref.edit();
now you will have to use this editor directly wherever it is required.
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();