Develop Reference

sharedpreferences is not saving the text value

**
I am trying to save the text variable using Sharedpreferences. I saved the variable by this code. But when I click the button the saved variable will go back to 0. I want to start counting from the saved value. please help me
**int counter = 0;
public static final String SHARED_PREF="shared";
public static final String TEXT="text";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
counterView=findViewById(R.id.counterid);
Btn=findViewById(R.id.button1);
Btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
counter++;
counterView.setText(Integer.toString(counter));
SharedPreferences sp = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.putString(TEXT,counterView.getText().toString());
editor.commit();
}
});
SharedPreferences sp = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
String tValue = sp.getString(TEXT,"");
counterView.setText(tValue);
}
}

Considering the informations you've provided I think you needed to give the counter the value stored in SharedPreferences, to continue the count from that, when the button was pressed again.
Try this:
int counter = 0;
Button adBtn;
TextView counterView;
public static final String SHARED_PREF="shared";
public static final String TEXT="text";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counterView=findViewById(R.id.counterid);
adBtn=findViewById(R.id.button1);
adBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences counterSp = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
String correctCounterValue = counterSp.getString(TEXT,"");
counter = Integer.valueOf(correctCounterValue);
counter++;
counterView.setText(Integer.toString(counter));
SharedPreferences sp = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.putString(TEXT,counterView.getText().toString());
editor.commit();
}
});
SharedPreferences sp = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
String tValue = sp.getString(TEXT,"");
counterView.setText(tValue);
}

App crashes when using Shared Preferences

Im making a simple app, which counts the clicks of a button and saves the integer with a Shared Preferences. I tried it with the following code, but the app crashes all the time, if I try to open "Singleplayer"
public class Singleplayer extends AppCompatActivity {
private int sp1;
private int record;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_singleplayer);
final Button button1 = (Button) findViewById(R.id.buttonspieler1);
final TextView lbl1 = (TextView)findViewById(R.id.lblspieler1);
final TextView lbl2 = (TextView)findViewById(R.id.lblrekord);
SharedPreferences data_record = getSharedPreferences("savegame", 0);
record = data_record.getInt("myKey1", 0);
lbl2.setText(String.valueOf(record));
button1.setOnClickListener(new View.OnClickListener()
{
public void onClick(final View v)
{
if(sp1< record) {
sp1++;
lbl1.setText(String.valueOf(sp1));
}
else if(sp1>= record)
{
sp1++;
record++;
lbl1.setText(String.valueOf(sp1));
lbl2.setText(String.valueOf(record));
}
}
});
}
#Override
protected void onStop() {
super.onStop();
SharedPreferences data_record = getSharedPreferences("savegame", 0);
SharedPreferences.Editor editor = data_record.edit();
editor.putString("myKey1", String.valueOf(record));
editor.commit();
}
}

you are using sharedPrefrence in your onStop() so you will face many issue here, i suggest to use it at the end of click method
button1.setOnClickListener(new View.OnClickListener()
{
public void onClick(final View v)
{
if(sp1< record) {
sp1++;
lbl1.setText(String.valueOf(sp1));
}
else if(sp1>= record)
{
sp1++;
record++;
lbl1.setText(String.valueOf(sp1));
lbl2.setText(String.valueOf(record));
}
SharedPreferences data_record = getSharedPreferences("savegame", 0);
SharedPreferences.Editor editor = data_record.edit();
editor.putString("myKey1", String.valueOf(record));
editor.commit();
}
});
so why the app crash, because the sharedPref dosen't carry any value it's null
please check this

Show current SeekBarPreference value into ScreenPreference

what's a good way to show current value of SeekBarPreference into ScreenPreference.
I've tried to insert textview but the app crashes.
Any suggestions?
preferences.xml
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<SeekBarPreference
android:id="#+id/seekbar_pref"
android:key="seekbar_x"
android:title="Value"
android:defaultValue="1"
android:max="60"/>
</PreferenceScreen>
Preferences.java
public class Preferences extends PreferenceActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
}
public static class MyPreferenceFragment extends PreferenceFragment
{
#Override
public void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
}
}
Main.java
private SharedPreferences.OnSharedPreferenceChangeListener preferenceChangeListener = new SharedPreferences.OnSharedPreferenceChangeListener() {
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
Log.e("SHARED", "VAL: " + sharedPreferences.getInt("seekbar_x",10));
}
};

In your onCreate method add this line at the end (after adding preferences):
SeekBarPreference pref = (SeekBarPreference) findPreference("seekbar_pref");
Then add the listener on it like this:
pref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
int value = mSeekBarPreference.getProgress(); //or (int) newValue
//You can now use this value wherever you like:
pref.setSummary("Value: " + value);
return true;
}
});

loadPreference() for preferenceActivity method throws exception first time app is installed

I am a newbie to android, so please be patient.
I am trying to learn preferences. I have an app that has a mainActivity, when the menu icon it's pressed a MyPreferenceActivity is shown. It allows the user setting some preferences related to a subject.
In my mainActivity I have a loadPrefernces method that works fine when the app is installed, but the first time it throws an error: unable to start activity component info[..] java.lang.NullPointerException
Here is my code:
MainActivity
public class MainActivity extends Activity {
public static final String PREFERENCE_FILENAME = "com.id11298775.exercise6_preferences";
SharedPreferences mSharedPreferences;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
loadPreferences(); // this cause the error
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
Intent i = new Intent(MainActivity.this, MyPreferenceActivity.class);
startActivity(i);
break;
}
return true;
}
#Override
protected void onResume() {
super.onResume();
loadPreferences();
}
private void loadPreferences() {
mSharedPreferences = getSharedPreferences(PREFERENCE_FILENAME,
MODE_PRIVATE);
// Setting the textView related to the subject
TextView subjectTv = (TextView) findViewById(R.id.activitymain_favouritesubjectresult_tv);
subjectTv.setText(mSharedPreferences.getString("list_subject_pref",
null));
// Setting the TextView related to the URL
TextView urlTv = (TextView) findViewById(R.id.activitymain_handbookurlresult_tv);
urlTv.setText(mSharedPreferences.getString("et_subject_pref", null));
// Setting the TextView related to the times selected
TextView labTimeTv = (TextView) findViewById(R.id.activitymain_labtimeresult_tv);
// #SuppressWarnings("unchecked")
Map<String, ?> map = mSharedPreferences.getAll();
Object cs = map.get("list_times_pref");
labTimeTv.setText(cs.toString());
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
this is my MyPreferenceActivity
public class MyPreferenceActivity extends PreferenceActivity implements
OnSharedPreferenceChangeListener {
#SuppressWarnings("deprecation")
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preference);
}
#SuppressWarnings("deprecation")
#Override
protected void onResume() {
super.onResume();
getPreferenceScreen().getSharedPreferences()
.registerOnSharedPreferenceChangeListener(this);
}
#SuppressWarnings("deprecation")
#Override
protected void onPause() {
super.onPause();
getPreferenceScreen().getSharedPreferences()
.unregisterOnSharedPreferenceChangeListener(this);
}
#SuppressWarnings("deprecation")
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
String key) {
if (key.equals("list_subject_pref")) {
ListPreference preference = (ListPreference) findPreference(key);
CharSequence currText = preference.getEntry();
preference.setSummary(currText);
} else if (key.equals("et_subject_pref")) {
EditTextPreference preference = (EditTextPreference) findPreference(key);
String newUrl = preference.getText().toString();
preference.setSummary(newUrl);
} else if (key.equals("list_times_pref")) {
Set<String> selections = sharedPreferences.getStringSet(
"list_times_pref", null);
String[] selected = selections.toArray(new String[] {});
String listSelection = "";
for (int i = 0; i < selected.length; i++) {
listSelection += selected[i] + " ";
}
MultiSelectListPreference multi = (MultiSelectListPreference) findPreference(key);
multi.setSummary(listSelection);
} else if (key.equals("ringtonePref")) {
RingtonePreference preference = (RingtonePreference) findPreference("ringtonePref");
String strRingtonePreference = ((SharedPreferences) preference).getString("ringtonePref", "none");
Uri ringtoneUri = Uri.parse(strRingtonePreference);
Ringtone ringtone = RingtoneManager.getRingtone(this, ringtoneUri);
String name = ringtone.getTitle(this);
preference.setSummary("select " + name);
}
}
}
here is logcat:
I think that the first time the app is installed there are no preference set, therefore the error, but I can't figure out a good way to prevent the exception.
Anybody can please help me?

listener sharedpreferences

I've a problem with this code. I want keep preferences values in my app but I've problem with the listener. Does not work, its does not save new values. Any idea about error(s)?
EDIT: onResume() works because when I open an activity on my app and close it, the value of sharepreferences is correct. Dialogs and activities does not keep values.
public void onCreate(){
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
public void onSharedPreferenceChanged(SharedPreferences prefs, String listpref) {
if(!preferencesChanged)preferenze();
}
};
sp.registerOnSharedPreferenceChangeListener(listener);
There are some buttons and other info activities called by intents.
A TextView that show a value from array and nothing.
public void onPause() {
super.onPause();
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
sp.unregisterOnSharedPreferenceChangeListener(listener);
protected void onResume() {
super.onResume();
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
public void onSharedPreferenceChanged(SharedPreferences prefs, String listpref) {
preferencesChanged = true;
}
};
sp.registerOnSharedPreferenceChangeListener(listener);
protected void onStop(){
super.onStop();
if(preferencesChanged){
//Update the app
preferenze();
}
public void preferenze()
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
CheckboxPreference = prefs.getBoolean("checkboxPref", true);
ListPreference = prefs.getString("listpref", "");
Others variables and most if/else.
Preferences.xml:
public class Preferences extends PreferenceActivity implements OnSharedPreferenceChangeListener{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.layout.preferences);
}
#Override
public void onSharedPreferenceChanged(SharedPreferences prefs, String listpref) {

protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.settings); SharedPreferences sp = PreferenceManager .getDefaultSharedPreferences(this); sp.registerOnSharedPreferenceChangeListener(this); }
I think, you are missing registerOnSharedPreferenceChangeListener