Develop Reference

Android, SharedPreferences default values not set if there is no pref

String getString(String name, String defValue){...}
This is the definition of getString(...) method of SharedPreferences so I think it's possible if I run code below, it returns 1 two times:
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context);
Timber.e(pref.getString("new", "1"));
Timber.e(pref.getString("new", "100"));
because at the first time its empty, so "1" will store, after that because of it has value ("1"), it will return it's value ("1") not default value ("100")
but it returns "1" and "100" and "new" does not store in my pref file (located in data/data/...)
Am I understanding it wrong or something goes wrong in this code?

Use can only get The data using getString.
to store data use Editor.commit();
Editor editor = settings.edit();
editor.putString("someKey", "someVal");
editor.commit();
only after that you can get this value.
String value = settings.getString("someKey", "someDefaultValueIfThisKeyNotUsedBefore");
In this example, you will recieve "someVal" if commit is used beforehand.

You must put"Something" to SharedPreferences.Editor, and commit them.
pref.getString wont store anything.
Refer to the links below:
https://developer.android.com/reference/android/content/SharedPreferences.html
https://developer.android.com/reference/android/content/SharedPreferences.Editor.html

Shared Preferences saving an int?

I saw this on stack Need to save a high score for an Android game
This is what it told me
//setting preferences
SharedPreferences prefs = this.getSharedPreferences("myPrefsKey", Context.MODE_PRIVATE);
Editor editor = prefs.edit();
editor.putInt("key", score);
editor.commit();
//getting preferences
SharedPreferences prefs = this.getSharedPreferences("myPrefsKey", Context.MODE_PRIVATE);
int score = prefs.getInt("key", 0); //0 is the default value
I was wondering, should "key" be the string where the highscore is located? and does it matter what i name my prefs key.
Thanks for your time.

The Android Developers documentation is an excellent place to start with any question like this. SharedPreferences can be found here. SharedPreferences is a simple Key-Value pair storage, so if you put an int into your shared preferences as with the key "high score", then in the future, if you want to get that int, you need to use prefs.getInt("high score"). It doesn't matter what you name your keys, but it is generally good practice to use private static final string variables to store keys you will use on a regular basis.

You can name the string whatever you like. Click here for documentation. You can name it anything from "foo" to "bar".

Does SharedPreferences work in Eclipse emulator?

I am attempting to save a user id using SharedPreferences. Do values saved as SharePreferences persist across all Activities in my application so I can access the userid from any application? Below is my code for saving the userid.
userid = result.substring(3, result.length());
Log.d("userid at onpostexecute", userid);
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit(); // to update userid
editor.putString("userid", userid);
editor.commit();
And here is the code for accessing the userid from the SharedPreferences in another activity.
SharedPreferences prefs = getPreferences(MODE_PRIVATE); // to access userid
String userid = prefs.getString("userid", "");
Log.d("shared prefs userid", userid);
What is strange is that the above code is in my onCreate method but it doesn't show up in the Logcat even though other log data is displayed before and after this code. So is there something wrong with my code that I can't even get it to display in my logcat? I can't even tell if it is being updated.

Values saved as sharedPreferences can be shared between activities if you tell it to. Right now you are creating a preference that is only accessible to that same activity. You need to use:
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = preferences.edit();
Like this you are creating a sharedPreference between your application. There is a lot of explanation on the topic in the accepted answer to another question. Link to question
As discussed in the answer the way you are using to save the preference will only work in the same activity that saved it.

I assume you mean can you access them from any Activity, yes, they do persist even when you leave your app and come back. From the Docs
The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).
If this Log.d("userid at onpostexecute", userid); doesn't even show up then I would put a breakpoint there and make sure you have a value for userid. I would also check your logcat filters to make sure that you are getting all logs. Just make sure that the type in the spinner is set to "verbose" just to be sure

How to retrieve name from Edittext for further manipulation?

i have almost completed my game and now i wish to do something with the scores and name so i want to have a high score list...
The problem is that i cannot retrieve the name when i m trying to draw the name using alphabet bitmaps what i have preprared!!!
now the problem occurs when i m tryin to use the getSharedpreferences and m not able to copy the name anywhere in the whole project so that when in the activity of showing the high score i can draw it!!!
is there a simple way to do it please suggest!!!!
thank you!!!

The best way to store a value which will be available all around your application is, as you said, the SharedPreferences.
To store your name user you can do this:
SharedPreferences mPrefs = getSharedPreferences("MyPreferences", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = mPrefs.edit();
editor.putString("username", "your name");
editor.commit();
To retrieve your username you can do this:
SharedPreferences mPrefs = getSharedPreferences("MyPreferences", Context.MODE_PRIVATE);
String username = mPrefs.getString("username", "");

Start a specific part of an application only one time after installation

On my app I've got a Database which i have to fill one time with some entries. I have packed this step in my splashscreen. Now I got the problem every time i open up my application it puts again all entries to my database.
I'm looking for a way to let this happen only on the really first time the app gets opend. But i don't find out, how i can realize this.
I'm happy over every input and Idea!
Have a nice day
safari
Notes
I had an idea to realize that. I make a boolean in my SplashScreen, which takes a look at the database table if there is nothin, it inputs all the entries and makes a mark in a table that its filled like yes.
Afterwards if i open the app again it takes a look at the database if theres a yes or what ever i definied, it doesn't put again all entries in my database.
Sorry for that crappy definition of what my idea is, my english isnt the best.
I'm searching for an easier way than this.

why not have a startup activity that checks if the app is launched for the first time ( and stores the value in the app preferences ) and either forwards to the database setup activity or to the main activity....
Here's a sample on how to read and write to the preferences:
Define preference key:
public static final String KEY_APP_IS_INITIALIZED = "APP_INITIALIZED";
read boolean value from preferences:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context)
boolean appIsInitialized = prefs.getBoolean(KEY_APP_IS_INITIALIZED, false);
store boolean value to preferences:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context)
Editor editor = prefs.edit();
editor.putBoolean(KEY_APP_IS_INITIALIZED, true);
editor.commit();
Launching the activities:
Intent intent = new Intent(startup_activity,
db_initialized ?
MainActivity.class :
DbInitActivity.class);
startup_activity.startActivity(intent);

You could use SharedPreferences to store a boolean value which indicates if the database is already filled.
You can store the data using this code:
SharedPreferences pref = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();
editor.putBoolean(key, value);
editor.commit();
and then when you start the application you just read your value using:
SharedPreferences pref = getPreferences(MODE_PRIVATE);
pref.getBoolean(value, false);

// Check if DB is set up on start
SharedPreferences settings = getSharedPreferences("yourappidentifiername",MODE_PRIVATE);
String DbSetUp = settings.getString("dbsetup", "no");
// DbSetUp is "no" or "yes"
// Set that DB is set up
SharedPreferences settings = getSharedPreferences("yourappidentifiername",MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString("dbsetup", "yes");
editor.commit();

Not an optimal solution, but you could check for one of your entries, if they don't exist, add them to your DB, otherwise ignore them.

Try this....
Have one bool value in shared preferences.
Check that variable is set or not on each start of the application.
if not set then set it and perform db operation.
if set don't do db operation just go to next steps.

I've got an idea, reading other answers.
Use a version for the database to write in the sharedpreference, so next time you'll need to update the database, just delete the old one and refill the new one with you data.
public void populateResDB(int version){
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
int resDbVersion = prefs.getInt("ResDBVersion", 1);
if(resDbVersion<version){
//Populate database here
//Delete table/db
//Populate the table/database with new or updated data
//Update ResDBVersion for the next time
Editor editor = prefs.edit();
editor.putInt("ResDBVersion", version);
editor.commit();
}else{
//installed db has the same version as the one we want to install
//so, do nothing.
}
}
I'm trying it now, not yet tested.
In the onCreate of the splash activity use:
populateResDB(1); //1 is for the first time, increase it manually

You can use method onCreate in your database helper - it's used only, when new database is created, so I think that is what you're looking for.