I want to delete SharedPreferences from my application bt nothing happens

Question

I'm trying to delete shared preferences on another activity when the user press logout button. First I added my variables to the SharedPreferences, related code is below.

SharedPreferences shared_preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                            SharedPreferences.Editor editor = shared_preferences.edit();
                            int id = Integer.parseInt(cursor.getString(0));
                            String name = cursor.getString(1);
                            String surname = cursor.getString(2);
                            String email = cursor.getString(3);
                            String username = cursor.getString(4);
                            String password = cursor.getString(5);
                            byte[] photograph = cursor.getBlob(6);
                            String saveThis = Base64.encodeToString(photograph, Base64.DEFAULT);
                            editor.putInt("id",id);
                            editor.putString("name",name);
                            editor.putString("surname",surname);
                            editor.putString("email",email);
                            editor.putString("username",username);
                            editor.putString("password",password);
                            editor.putString("photograph",saveThis);
                            editor.commit();
                            login_screen = new Intent(Login.this, NavigationDrawer.class);
                            startActivity(login_screen);

Now, I will delete the all variables from the SharedPreferences but when I trying to login in different account nothing happens and all my data is still in SharedPreferences. How will I delete all variables ? Here is the code

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                            SharedPreferences.Editor editor = preferences.edit();
                            editor.clear();
                            editor.commit();
                            Intent moveToMain = new Intent(getApplicationContext(), Login.class);
                            moveToMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |  Intent.FLAG_ACTIVITY_CLEAR_TASK);
                            startActivity(moveToMain);

You seem to be storing too much in the preferences; have you considered using a database to store user information? — Eenvincible, May 03 '17 at 07:19
nothing happens means how u check it is removing all data from prefarances or not ?? it should happen — Tufan, May 03 '17 at 07:20
Can you post the code where you check for the prefference, to see it is not deleted — X3Btel, May 03 '17 at 07:31
Have you tried to debug, just to see if you get the same shared preferences? — Tima, May 03 '17 at 07:31
And another idea, maybe it's because of getDefaultSharedPreferences. Look at http://stackoverflow.com/a/10786739/408780 — Tima, May 03 '17 at 07:36

score 0 · Answer 1 · answered May 03 '17 at 07:11

If you have set android:allowBackup="true" in your AndroidManifest.xml, then set it to false as Android keeps an auto backup from Android 6.0 including the following :

Shared preferences files.
Files in the directory returned by getFilesDir().
Files in the directory returned by getDatabasePath(String), which also includes files created with the SQLiteOpenHelper class.
Files in directories created with getDir(String, int).
Files on external storage in the directory returned by getExternalFilesDir(String).

For more information on this, visit the following link : https://developer.android.com/guide/topics/data/autobackup.html

I don't think that this will work. In general, the `allowBackup` is useful when the user uninstalls the app, not in a journey through the app. By setting the flag to true, it will restore the values when the app is reinstalled. — Iulian Popescu, May 03 '17 at 07:21

score 0 · Answer 2 · answered May 03 '17 at 07:41

What you can try is to set all the variables in your SharedPreference instance to null like this:

SharedPreferences shared_preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = shared_preferences.edit();

                        editor.putInt("id",-1);
                        editor.putString("name",null);
                        editor.putString("surname",null);
                        editor.putString("email",null);
                        editor.putString("username",null);
                        editor.putString("password",null);
                        editor.putString("photograph",null);
                        editor.commit();

This will ensure that all the variables have been reset

score 0 · Answer 3 · answered May 03 '17 at 07:58

0

Sorry guys I think I found the problem when I debugging the variables comes from the database are always same. Thanks for help.

answered May 03 '17 at 07:58

Serdar Yazici

39
3

I want to delete SharedPreferences from my application bt nothing happens

3 Answers3