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clear the value of sharedpreferences

i am kind of new to android programming , i am designing a program that has login page and main page.When i sign in for the first time with a username and password, i created a sharedpreferences to remember that username and whenever i enter program , it skips login page and redirects me to main page.What i want to do is, when i press logout button in login page ,i want sharedpreferences forget the value of username in my database(it wont delete it from database) and force me to login me again with the same or different username and password , and i dont want to be redirected to main page when i enter application.I found something like SharedPreferences.Editor.remove() , SharedPreferences.Editor.clear(),commit() ,etc.. But code didnt work.Can you help?
public static class SaveSharedPreference {
static final String PREF_USER_NAME = "username";
static SharedPreferences getSharedPreferences(Context ctx) {
return PreferenceManager.getDefaultSharedPreferences(ctx);
}
public static void setUserName(Context ctx, String userName) {
SharedPreferences.Editor editor = getSharedPreferences(ctx).edit();
editor.putString(PREF_USER_NAME, userName);
editor.commit();
}
public static String getUserName(Context ctx) {
return getSharedPreferences(ctx).getString(PREF_USER_NAME, "");
}
}
Button btnSignIn, btnSignUp;
LoginDataBaseAdapter loginDataBaseAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_uye_kayit_giris);
if (SaveSharedPreference.getUserName(UyeKayitGirisActivity.this).length() == 0) {
Intent i = new Intent(UyeKayitGirisActivity.this, MainActivity.class);
startActivity(i);
// finish();
}
// create a instance of SQLite Database
loginDataBaseAdapter = new LoginDataBaseAdapter(this);
loginDataBaseAdapter = loginDataBaseAdapter.open();
// Get The Refference Of Buttons
btnSignIn = (Button) findViewById(R.id.buttonSignIN);
btnSignUp = (Button) findViewById(R.id.buttonSignUP);
// Set OnClick Listener on SignUp button
btnSignUp.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
/// Create Intent for SignUpActivity abd Start The Activity
Intent intentSignUP = new Intent(getApplicationContext(), SignUPActivity.class);
startActivity(intentSignUP);
}
});
Button btn_exit;
// super.onCreate(savedInstanceState);
// setContentView(R.layout.main1);
btn_exit = (Button) findViewById(R.id.buttonLogOUT);
btn_exit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// WHAT SHOULD I WRITE IN HERE?????????????
Toast.makeText(UyeKayitGirisActivity.this, "ÜYE GİRİŞİ TEKRAR ZORUNLU HALE GETİRİLDİ!!!", Toast.LENGTH_LONG).show();
}
});
}

Try like this
SharedPreferences pref = mContext.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
Editor editor = pref.edit();
editor.clear();
editor.commit();

Here is the Method
private void removePreference(Context context, String prefsName, String key) {
SharedPreferences preferences = context.getSharedPreferences(prefsName, Activity.MODE_PRIVATE);
android.content.SharedPreferences.Editor editor = preferences.edit();
editor.remove(key);
editor.apply();
}
You can call it like:
public void removeUser() {
removePreference(context, FILENAME, KEY_USER);
}

Since you have mentioned that you do NOT want to delete the value of login from shared preference but only ask for login page each time, I believe you are looking for something where you want to clear application cache programatically.
Please check, Clear Cache in Android Application programmatically and Clear Application's Data Programmatically
It is also worth reading this wonderful answer - Don't delete database or shared Preference on clear app

To remove them all SharedPreferences.Editor.clear() followed by a commit()

Remember click in Android

I have created an activity that should be displayed only once. In this Activity, I added a button, and click its close and will not reopen anymore when the application is started again. I thought of using SharedPreferences, but I do not get the desired result.
I memorize a data in Shared:
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button1:
SharedPreferences userDetails = getSharedPreferences("entrato", MODE_PRIVATE);
Editor edit = userDetails.edit();
edit.clear();
edit.putString( "entrato", "entra" );
edit.commit();
this.finish();
break;
}
}
then, in OnCreate() of the previous activity call the Shared and if the data is present do not open the activity:
//remember click
SharedPreferences userDetails = getSharedPreferences("entrato", MODE_PRIVATE);
String valore = userDetails.getString("entrato", "");
if (valore.equals("entra")){
return;
}else{
Intent intent = null;
intent = new Intent(this, Benvenuto.class);
startActivity(intent);

create share preference class like this:
public class MyPreference {
private static final String APP_SHARED_PREFS = "myPref";
private SharedPreferences appSharedPrefs;
private Editor prefsEditor;
public MyPreference(Context context) {
this.appSharedPrefs = context.getSharedPreferences(APP_SHARED_PREFS, Activity.MODE_PRIVATE);
this.prefsEditor = appSharedPrefs.edit();
}
public boolean loadServices(String servicName) {
return appSharedPrefs.getBoolean(servicName, false);
}
public void saveServices(String servicName, boolean isActivated) {
prefsEditor.putBoolean(servicName, isActivated);
prefsEditor.commit();
}
}
then On Oncreate activity check if service exist so wont show and exit.
public static MyPreference myPref = new MyPreference(this);
if(myPref.loadService("this is not first time")){
thisActivity.finish();
}else {
// so it's first time and you can do what ever you want to do
}
and go on you click events and save service like this.
public static MyPreference myPref = new MyPreference(this);
myPref.saveService("this is not first time");

Try this code instead
// save string
static public boolean setPreference(Context c, String value, String key) {
SharedPreferences settings = c.getSharedPreferences(PREFS_NAME, 0);
settings = c.getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value);
return editor.commit();
}
// retrieve String
static public String getPreference(Context c, String key) {
SharedPreferences settings = c.getSharedPreferences(PREFS_NAME, 0);
settings = c.getSharedPreferences(PREFS_NAME, 0);
String value = settings.getString(key, "");
return value;
}

I have Four activities
Splash
Have 2 Buttons And 1 CheckBox ( Remember Me)
3 & 4. Another Activity
If I check the remember me option using checkbox, then I have to remember the button I have clicked and then start the 3rd or 4th activity directly whenever next start.

how to save some value in sharedpreferences and get that in next activity

I'm creating a Quiz App, I ask some questions and give options in the form of radio buttons, now I want to store value of of answer (plus on right answer and minus on wrong one) in SharedPreferences and show that result in other activity. I have searched and found this answer here
I used that but still I'm unable to get my desired results
My code Looks Like :
Main Activity which saves some value in SharedPreferences:
public class MainActivity extends Activity {
private SharedPreferences saveScore;
private SharedPreferences.Editor editor;
RadioGroup group;
RadioButton radioButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
group = (RadioGroup) findViewById(R.id.radioGroup1);
radioButton = (RadioButton) group.findViewById(group.getCheckedRadioButtonId());
saveScore = getPreferences(MODE_PRIVATE);
}
public void gotoNextAndSaveScore(View view) {
if(group.getCheckedRadioButtonId() != R.id.radio3){
editor = saveScore.edit();
editor.putInt("score", -1);
editor.commit();
}else{
editor = saveScore.edit();
editor.putInt("score", 1);
editor.commit();
}
Intent intent = new Intent (MainActivity.this, NextActivity.class);
startActivity(intent);
}}
this is the Next Activity which tries to get values from SharedPreferences:
public class NextActivity extends Activity{
private SharedPreferences preferences;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_next);
preferences = this.getSharedPreferences("score", MODE_WORLD_WRITEABLE);
int value = preferences.getInt("score", 0);
String score = "Your Score is : " + value;
UIHelper.displayScore(this, R.id.tvScore, score );
}}
does any one know how to that?

You should change the line
saveScore = getPreferences(MODE_PRIVATE);
To
saveScore = getSharedPreferences("score",Context.MODE_PRIVATE);

Store the value when navigating to nextActivity during onPause() as below:
#Override
protected void onPause()
{
super.onPause();
// Store values between instances here
SharedPreferences preferences = getSharedPreferences("sharedPrefs", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("YourStringKeyValue", "StringValue"); // value to store
// Commit to storage
editor.commit();
}
and get the data with that key in next Activity's onCreate as below:
SharedPreferences preferences = getSharedPreferences("sharedPrefs", 0);
String name= preferences.getString("YourStringKeyValue","");

try this,
public class DataStorage {
private static String KEY;
public static SharedPreferences savedSession;
public void saveID(Context context, String msessionid) {
// TODO Auto-generated method stub
Editor editor = context
.getSharedPreferences(KEY, Activity.MODE_PRIVATE).edit();
editor.putString("SESSION_UID", msessionid);
editor.commit();
}
public String getID(Context context) {
savedSession = context.getSharedPreferences(KEY, Activity.MODE_PRIVATE);
return savedSession.getString("SESSION_UID", "");
}
}
Edit:
DataStorage mdata = new DataStorage();
public void gotoNextAndSaveScore(View view) {
if(group.getCheckedRadioButtonId() != R.id.radio3){
mdata.saveId(Mainactivity.this,1);
}else{
mdata.saveId(Mainactivity.this,-1);
}
And then get value from NextActivity.
DataStorage mdata = new DataStorage();
mdata.getId(NextActivity.this);

You're using the wrong preference file, the getPreference function on Activity returns a file private to that Activity. You need to use the named file version- getSharedPreferences(name, mode)

User setup activity of android app

I want to create a simple app to upload my location .I have two activities and in first activity the user can input parameters url for upload with editbox , a checkbox if user wish upload location save preferences button and start button for go to get location activity.I try this but no work...How i call my function start and save?Any help?I have errors when debug...after click button
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SharedPreferences preferences = getSharedPreferences("gpstracker" , MODE_PRIVATE);
String strValue = preferences.getString("Url",strValued);
edittxtUrl = (EditText)findViewById(R.id.txtUrl);
edittxtUrl.setText(strValue);
Button buttonStart = (Button)findViewById(R.id.buttonStart);
buttonStart.setOnClickListener(startListener);
Button buttonSave = (Button)findViewById(R.id.buttonSave);
buttonSave.setOnClickListener(saveListener);
}
private OnClickListener startListener = new OnClickListener() {
public void onClick(View v) {
Start();
}
};
private OnClickListener saveListener = new OnClickListener() {
public void onClick(View v) {
Save();
}
};
public void Save() {
SharedPreferences preferences = getSharedPreferences("gpstracker" , MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
edittxtUrl = (EditText)findViewById(R.id.txtUrl);
String strUrl = edittxtUrl.getText().toString();
CheckBox chkTandC = (CheckBox)findViewById(R.id.chkTandC);
boolean blnTandC = chkTandC.isChecked();
editor.putString("Url", strUrl); // value to store
editor.putBoolean("TandC", blnTandC); // value to store
// Commit to storage
editor.commit();
}
public void Start() {
startActivity(new Intent(this, LocTracker.class));
}

Without your log cat it is somewhat hard to tell what your problem is, but what I think is happening is that you are passing a null view to the start method, and this is a problem because you are then trying to get a context. Effectively what you have written is
null.getContext()
which doesn't work. You can fix this by replacing view.getContext() with getApplicationContext()

How can I save ints to be retained even when the application is not running?

When I click on an option I want a check sign to appear to show it has been purchased. I am using SharedPreferences and have made all the links; however, when I click back or exit and then re-enter the application, the check is gone and any history of anything I did before is gone. How do I save the data so that it is kept even when the application is off or I'm at another page in the game. This is my code so far:
ImageView tick1;
int mYellCheck, mYellCheck1;
public static String sharedPrefs = "MyData";
SharedPreferences data;
SharedPreferences.Editor editor;
int mYellAlpha;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.upgrades);
update();
coins = Replay.totalCoins + Replay4.totalCoins + Replay5.totalCoins
+ Replay6.totalCoins;
data = getSharedPreferences(sharedPrefs, MODE_PRIVATE);
tick1.setAlpha(mYellCheck);
}
public void update() {
TextView coinScore = (TextView) findViewById(R.id.tvScore);
coinScore.setText("You have " + coins + " coins");
tick1 = (ImageView) findViewById(R.id.ivtick1);
ImageView moreYellow = (ImageView) findViewById(R.id.ivMoreYellow);
ImageView back = (ImageView) findViewById (R.id.ivBack);
back.setOnClickListener(this);
moreYellow.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.ivMoreYellow:
mYellAlpha = 255;
SharedPreferences.Editor editor = data.edit();
editor.putInt("MoreYellowUpgrade", mYellAlpha);
editor.commit();
data = getSharedPreferences(sharedPrefs, MODE_PRIVATE);
mYellCheck = data.getInt("MoreYellowUpgrade", 0);
tick1.setAlpha(mYellCheck);
break;
case R.id.ivBack:
Intent i = new Intent ("m.k.zaman.SpotActivity");
startActivity(i);
break;
}
}
EDIT
or Should i just use internal storage?

Try replacing your current onClick call to R.id.ivMoreYellow with this:
case R.id.ivMoreYellow:
mYellAlpha = 255;
mYellCheck = data.getInt("MoreYellowUpgrade", 0);
tick1.setAlpha(mYellCheck);
SharedPreferences.Editor editor = data.edit();
editor.putInt("MoreYellowUpgrade", mYellAlpha);
editor.commit();
break;
You were first overwriting all of the data in the SharedPreferences, and then calling to receive that data that you just overwrote, so I placed the getInt() call before the putInt(). Do you change mYellAplha to anything other than 255 though? If you don't you will never notice a change in SharedPreferences if you are always saving and getting 255.