I'm using SharedPreferences to save username but it's not working.
In login Activity (read):
ocUserName = (EditText)findViewById(R.id.userNameText);
SharedPreferences prefs = this.getPreferences(Context.MODE_PRIVATE);
String userNameKey = "userName";
String userNameTV = prefs.getString(userNameKey,null);
SharedPreferences.Editor editor = prefs.edit();
if(userNameTV != null) {
ocUserName.setText(userNameTV);
}
in second Activity (write):
SharedPreferences prefs =
getSharedPreferences("com.mesbahsoft.IRIB", MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
String userNameKey = "userName";
editor.putString(userNameKey, ocUser);
editor.commit();
Activity.getPreferences(int mode) (as used in your login activity) has a comment:
Retrieve a {#link SharedPreferences} object for accessing preferences that are private to this activity.
In your second activity you use Activity.getSharedPreferences(String name, int mode) and provide what looks like your Application Id as the name.
In effect, you are using two different sets of shared preferences in each activity.
I recommend using PreferenceManager.getDefaultSharedPreferences(Context context) if you intend to use the shared preferences throughout your application.
I assume the problem is that you are unable to read the written value. You need to use the same file in login activity:
SharedPreferences prefs = this.getSharedPreferences("com.mesbahsoft.IRIB", Context.MODE_PRIVATE);
If this does not work, kindly specify clearly where you are seeing the problem and also specify exceptions seen.
You are accessing different shared preferences in your activities,
this.getPreferences( Context.MODE_PRIVATE); is shorthand for this.getSharedPreferences( <activity's class name>, Context.MODE_PRIVATE);
In you login activity, use this,
getSharedPreferences("com.mesbahsoft.IRIB", MODE_PRIVATE);
References:
http://developer.android.com/reference/android/app/Activity.html#getPreferences(int)
http://developer.android.com/reference/android/content/Context.html#getSharedPreferences(java.lang.String,int)
Related
I am creating a location tracking application where I want the email-id of the logged in person as a global variable. As the email will keep changing depending on who logs in, i have a little confusion on how to go about with.
Thanku :)
Instead of creating Global variables please, Shared preferences and save them. Now, you can access them across the app or even after when user come back to app after closing App. Just as following :
SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("email", test#gmail.com);
editor.commit();
//to read shared prefere
SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
String defaultValue = "test#gmail.com"; //this is default email, so if you don't have values in preferences then it will be returned
String email= sharedPref.getString("email", defaultValue );
For details, Please follow Tutorial at: Official doc : SharedPreferences - Saving Key-Value Sets
As Kunu recomended, SharedPreferences are for these cases.
public static String PREFS_NAME = "loginDetails";
public static String LOGGED_EMAIL = "Email";
To edit your email:
public static void editEmail(String email)
{
Context context = getAppContext();
SharedPreferences.Editor editor = context.getSharedPreferences(PREFS_NAME, MODE_PRIVATE).edit();
editor.putString(LOGGED_EMAIL , email);
editor.apply();
}
For more details about SharedPreferences check this answer.
Sorry for my bad English.
On my application, I save token (it's a web app) in shared preferences. In first activity I do this:
(token = 123)
SharedPreferences sp = getPreferences(MODE_PRIVATE);
Editor ed = sp.edit();
ed.putString("token", Main.getToken());
ed.commit();
Log.d("Recieved token: ", sp.getString("token", "null")); // Recieved token: 123
As you see, shared prefs are saved.
I have another activity, which may be called from browser to share link.
Code:
sp = getPreferences(MODE_PRIVATE);
Log.d("Token recieved: ", sp.getString("token", "null")); // null
But on another activity shared prefs return null.
What can I do?
To explain the reason why getPreferences() didn't work for you:
When you call getPreferences() without specifying a Shared Preferences name, it returns a Shared Preference using the calling Activity's class name as the Shared Preference name. That's why you are getting null in your other activity - it's actually a different Shared Preference set that you are referring to.
Use getSharedPreferences instead, using whatever preferences name you like:
getSharedPreferences("my_prefs", Activity.MODE_PRIVATE);
That will then be available throughout your application. However using getPreferences() is suitable where you don't need to refer to the data stored outside of a particular Activity.
use like following,,
SharedPreferences mAppSettings = getSharedPreferences("SharedPref", MODE_PRIVATE);
SharedPreferences.Editor prefEditor = mAppSettings.edit();
prefEditor.putString(""token, "");
prefEditor.commit();
for retrieving,,,
final SharedPreferences mAppSettings1 = getSharedPreferences(
"SharedPref", MODE_PRIVATE);
String token= mAppSettings1.getString("token", "");
I want to store and retrieve data that is accessible to all activities in my app using SharedPreferences. Is that possible? Up until now I have been doing it such that the data is stored for a particular activity.
Yes. SharePreferences do exactly this.
In every activity you can this:
SharedPreferences prefs = getSharedPreferences(ApplicationConstants.PREFERENCES, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(name, value);
editor.commit();
And then retrieve values in other activty doing this:
mPrefs.getString(name, "");
This is the documentation:
http://developer.android.com/reference/android/content/SharedPreferences.html
And this is a good example to start with:
http://myandroidsolutions.blogspot.it/2012/03/android-preferenceactivity.html
Yes, that's the whole purpose of it.
Here's how you should write to it, via Editor
final SharedPreferences shp = ctx.getSharedPreferences(ctx.getString(R.string.app_name), Context.MODE_PRIVATE);
final SharedPreferences.Editor ed = shp.edit();
ed.putString("var1", "var1");
ed.putString("var2", "var2");
And to load it:
shp.getString("var1", "defvalue");
I have a better version. As sometimes when you try to do getSharedPreferences you might get an error as it could not be found.
This is how I store values in my Android projects.
Add
SharedPreferences sharedPreferences=this.getSharedPreferences("packagename", Context.MODE_PRIVATE);
sharedPreferences.edit().putString("username", "specify name here").apply();
Package Name can be directly copied from top of the activity ex: com.example.name.projectname
Retrieve
String username = sharedPreferences.getString("username","");
If you want to access values in all of your activities I think the better way is storing in a custom Application class and later in activities you can:
((CustomApplication)getApplication()).getStoredValue()
Shared preferences are stored in files and this file access is slower.
Is my example for create function for set and get an object data called "USER"
For set sharePreference data
public void saveUser(User usuario) {
SharedPreferences sharedPref = getSharedPreferences("A", Context.MODE_PRIVATE); // sharedpreference set named "A"
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("name", usuario.getNombre());
editor.putString("username", usuario.getUsername());
editor.putString("pass", usuario.getContrasena());
editor.putString("roll",usuario.getRol());
editor.commit();
}
For get sharePreference data
public Usuario getUser() {
SharedPreferences sharedPref = getSharedPreferences("A", Context.MODE_PRIVATE); // sharedpreference set named "A"
User usuario = new User();
usuario.setNombre(sharedPref.getString("name", "null"));
usuario.setUsername(sharedPref.getString("username", "null"));
usuario.setContrasena(sharedPref.getString("pass", "null"));
usuario.setRol(sharedPref.getString("roll", "null"));
return usuario;
}
Important: set name to sharePreference in this case "A"
I am trying to save a date in one activity and then have that date put in a textView in another activity. I am not sure about how to get the two activities to communicate with each other.
In file called report.java I have this method that gets the date and save it in sharedPrefernces.
private void updateLabel() {
date.setText(fmtDate.format(dateAndTime.getTime()));
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("date", date.getText().toString()); // value to store
editor.commit();
}
I am trying to figure out how to get my file called inspection use this to populate a textView
The problem I think I am having is with getting the correct name for the report file.
public static final String PREF_FILE_NAME = "report";
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
then I have this code on a method called onResume()
#Override
public void onResume() {
super.onResume();
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
String strDate=preferences.getString("date", date.getText().toString());
date.setText(strDate);
}
You are saving the value to two seperate preference files.
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
Use only one.
Why not use the default preference file that is accessible by all classes/activities of your app?
SharedPreferences preference = PreferenceManager.getDefaultSharedPreferences(yourContext);
preferences.edit().putString(YOURKEY, yourStrValue);
This way you are not creating extra preference files in your app that you have to remember which values are stored in which files. Definately makes life easier.
I have an Android application in which I have my preferences in an XML file, which works fine. I now want to set one of the preferences using code instead of displaying the entire preference screen, how would I go about doing this?
I assume by preferences you are referring to your application's preferences and not Android phone settings.
To store preferences between runs of you application you need to do the following
Create a SharedPreferences object
SharedPreferences settings = getSharedPreferences(String n, MODE_PRIVATE);
String n identifies your preferences and the second argument is the mode they'll be accessed
Instantiate an Editor object
SharedPreferences.Editor editor = settings.edit();
Note: do not try settings.editor.edit(), this will not make a persistent object and the code below will not work
Write your preferences to the buffer
editor.put...(String, value)
There are numerous put function, putString, putBoolean, etc. The String is the key ("version", "good run") and the value is the value ("1.5.2", true)
Flush the buffer
editor.commit();
This actually writes you put to the preferences. If your app crashes before this line then the preferences will not be written. There is also a documented bug: commit() is supposed to return a boolean indicating success or failure. Last I checked it always returned false.
These preferences will by stored on the phone and will only be accessible to your application.
More documentation is here
I tried this but didn't work:
SharedPreferences settings = getSharedPreferences(String n, MODE_PRIVATE);
Try this instead:
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
You can save something in the sharedpreferences by using below code
public static void save(String valueKey, String value) {
SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(context);
SharedPreferences.Editor edit = prefs.edit();
edit.putString(valueKey, value);
edit.commit();
}
To read preferences:
public static String read(String valueKey, String valueDefault) {
SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(context);
return prefs.getString(valueKey, valueDefault);
}