I want to utilize the sharedpreferences in my app, but in all of the tutorials and documentation in the internet I can not find out where to put the file that I am suppose to use.
What I mean is, when trying to access it as so:
public static final String PREFS_NAME = "AOP_PREFS";
SharedPreferences settings = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
I don't know where to put the file AOP_PREFS.xml so that my class can use it. Am I missing something and I'm not suppose to be creating a file?
I don't quite understand what you are trying to do here. If your code is in an activity class, you just need to call getSharedPreferences(int) instead of getSharedPreferences(String, int). You get the preferences like this:
SharedPreferences prefs = getSharedPreferences (Context.MODE_PRIVATE);
Or you can use the PreferenceManager class to get the shared preferences as well:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
where this is a Context object.
You can retrieve a string from the preferences using a key (In this case, myString).
prefs.getString ("myString", "");
If you have not saved a string with the myString key, the second parameter will be returned.
This is how you can save a string into the preferences:
prefs.edit().putString ("myString", "Some String value");
The first parameter is the key, and the second is the value. Self-explanatory!
NOW REMEMBER! Every time you save something, call apply()!
prefs.edit().putString ("myString", "Some String value").apply();
*******
And that's all you have to know about shared preferences!
Using SharedPreferences, the file is automatically created in the files folder in internal storage of your app, so you don't need to explicitly do anything to create the file.
The file in this case will be AOP_PREFS.xml.
You can also just use "default" SharedPreferences, which will be stored in an xml file with the package name of your app.
Example of Writing to Default SharedPreferences:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sp.edit();
editor.putLong("some_value", someValue);
editor.commit();
Reading:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
Long someVal = sp.getLong("some_value", 0);
Note that unless you have a rooted device, you won't be able to view files in internal storage.
Related
So I have an application and i am trying to get one activity's shared preferences from a different activity. I cant use defaultSharedPreferences. Here is my code:
thisd = ma.
getSharedPreferences(
user, Context.MODE_PRIVATE);
Where thisd is the shared preferences, user is the specific sharedpreferences, and ma is the instance of the activity that has the shared preferences. Right now in activity called AddNameActivity.
Shared Preferences are not specific to any activity. It is common across application.
In the File where you add a value to Shared Prefernces, add this code sample.
SharedPreferences prefs = getSharedPreferences("your_file_name", MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("yourStringName", "this_is_the_saved_value");
editor.commit();
In the file where you want to read the value (may be second activity), add this code sample.
SharedPreferences prefs = getSharedPreferences("your_file_name",MODE_PRIVATE);
String string = prefs.getString("yourStringName","default_value");
You can use a default file to save/ read your preferences.
In that case, Just replace the first line of the two code snippets above by this:
SharedPreferences prefs = getDefaultSharedPreferences(getApplicationContext());
Here is code I am Using to create and store value in Preference.
outgoing is String variable.
SharedPreferences sp = getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.putString("PhoneNo","Hi");
editor.commit();
Here is the code to get value from SharedPreference.
SharedPreferences sp
=getSharedPreferences(outgoing,Activity.MODE_PRIVATE);
String calln = sp.getString("PhoneNo","0");
Toast.makeText(mContext, "SHARED"+calln,Toast.LENGTH_LONG).show();
You should probably call the getSharedPreferences on the context from which you are accessing them.
Source
Therefore, depending on how you can access your context, if you pass it to some other activity or in an asynchronous task, here are some examples of usage:
this.getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
context.getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
getApplicationContext().getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
Also, one way you can test your stuff is to use a listener when SharedPreferences get changed:
onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
Called when a shared preference is changed, added, or removed.
here is how to do that
You can also use the Preference Manager to obtain the SharedPreferences:
PreferenceManager.getSharedPreferences(YOUR_CONTEXT).getString(
"PhoneNo", "0");
Or to store them:
PreferenceManager.getSharedPreferences(YOUR_CONTEXT).edit().putString(
"PhoneNo", "Hi").commit();
The most likely reason that Shared Preference always returns the default value is that you saved the value in one preference file and then tried to retrieve it in another preference file. This can happen if you do call getPreferences() from different Activities, because getPreferences() creates a different preference file based on the activity it is created in.
Solution
The easiest solution is to always get your shared preferences like this:
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(context);
This will use a single preference file for the entire app.
Alternate solution
If for some reason you need to use different preference files, then you can do
final static String PREF_FILE_1 = "pref_file_1";
...
SharedPreferences sharedPref = context.getSharedPreferences(PREF_FILE_1, Context.MODE_PRIVATE);
Just make sure you always use the right file name for the preferences you are trying to save and retrieve.
Local preferences
If you really only need a preference for a specific Activity, then you can use getPreferences(Context.MODE_PRIVATE). Just don't expect to be able to retrieve the values from another Activity in the same way.
See also
This answer describes the differences between the various ways of obtaining SharedPreferences.
Difference between getDefaultSharedPreferences and getSharedPreferences
Mess with the shared preferences of android - which function to use?
change this Activity.MODE_PRIVATE to this Activity.MODE_MULTI_PROCESS, issue is probably due to different context during storing value and accessing value.
When putting values, try changing this:
SharedPreferences sp = getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
to this:
SharedPreferences sp = getApplicationContext().getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
Same when getting values - don't forget to add getApplicationContext() in your call to SharedPreferences
EDIT:
Check that your "outgoing" String is the exact same in both Activities
I have read that you can create more that one shared pref file, but I don't know how. This is how I normally use shared prefs.
SharedPreferences get;
SharedPreferences.Editor save;
get = PreferenceManager.getDefaultSharedPreferences(context);
save = PreferenceManager.getDefaultSharedPreferences(context).edit();
This makes the file named package.name_preferences.xml. So how can I create the file package.name_fileNames.xml and how I write and read from it?
Use getSharedPreferences(String name, int mode) on the activity instead of using the preference manager.
I am developing an Android app where the user has the facility of Facebook sharing. I have the login details of the user for the Facebook, now what I am trying to do is these login details should be saved until the application is not deleted.
When I tried to find the answer for this, I got some answers stating about shared preferences. But I am not cleared exactly how it works.
Here is what I am trying to do,
Username = username.getText().toString();
PassWord = password.getText().toString();
where username and password are 2 edittext fields. When the user enters for the first time into Facebook, I should save these data somewhere for my future reference so that he need not login again.
Can any one let me know how to achieve this?
// Save your info
SharedPreferences settings = getSharedPreferences("my_file_name", 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("username", username.getText().toString());
editor.putString("password", password.getText().toString());
editor.commit();
// Obtain your info
SharedPreferences settings = getSharedPreferences("my_file_name", 0);
String username = settings.getString("username", "");
String password = settings.getString("password", "");
A file will be created in:
data/data/[your.package.path]/shared_prefs/[your.package.path]_preferences.xml
You can use sharedPreference for this.
Many applications may provide a way to capture user preferences on the settings of a specific application or an activity. For supporting this, Android provides a simple set of APIs.
Preferences are typically name value pairs. They can be stored as “Shared Preferences” across various activities in an application (note currently it cannot be shared across processes). Or it can be something that needs to be stored specific to an activity.
Shared Preferences: The shared preferences can be used by all the components (activities, services etc) off the applications.
Activity handled preferences: These preferences can only be used with in the activity and can not be used by other components of the application.
Shared Preferences:
The shared preferences are managed with the help of getSharedPreferences method of the Context class. The preferences are stored in a default file(1) or you can specify a file name(2) to be used to refer to the preferences.
(1) Here is how you get the instance when you specify the file name
public static final String PREF_FILE_NAME = "PrefFile";
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
MODE_PRIVATE is the operating mode for the preferences. It is the default mode and means the created file will be accessed by only the calling application. Other two mode supported are MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE. In MODE_WORLD_READABLE other application can read the created file but can not modify it. In case of MODE_WORLD_WRITEABLE other applications also have write permissions for the created file.
(2) The recommended way is to use by the default mode, without specifying the file name
SharedPreferences preferences = PreferencesManager.getDefaultSharedPreferences(context);
Finally, once you have the preferences instance, here is how you can retrieve the stored values from the preferences:
int storedPreference = preferences.getInt("storedInt", 0);
To store values in the preference file SharedPreference.Editor object has to be used. Editor is the nested interface of the SharedPreference class.
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
Editor also support methods like remove() and clear() to delete the preference value from the file.
Activity Preferences:
The shared preferences can be used by other application components. But if you do not need to share the preferences with other components and want to have activities private preferences. You can do that with the help of getPreferences() method of the activity. The getPreference method uses the getSharedPreferences() method with the name of the activity class for the preference file name.
Following is the code to get preferences
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
int storedPreference = preferences.getInt("storedInt", 0);
The code to store values is also same as in case of shared preferences.
SharedPreferences preferences = getPreference(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
You can also use other methods like storing the activity state in database. Note Android also contains a package called android.preference. The package defines classes to implement application preferences UI.
Don't Use preferences to save facebook data:
Please use this code in Oncreate method:
if (isLoggedIn()) {
layout_after_fb_login.setVisibility(View.VISIBLE);
updateUI();
} else {
layout_after_fb_login.setVisibility(View.GONE);
}
////
private boolean isLoggedIn() {
AccessToken accesstoken = AccessToken.getCurrentAccessToken();
return !(accesstoken == null || accesstoken.getPermissions().isEmpty());
}
private void updateUI() {
Profile profile = Profile.getCurrentProfile();
if (null != profile) {
profilePictureView.setProfileId(profile.getId());
userNameView.setText(String.format("%s %s", profile.getFirstName(), profile.getLastName()));
layout_after_fb_login.setVisibility(View.VISIBLE);
} else {
layout_after_fb_login.setVisibility(View.GONE);
}
}
This question already has answers here:
How do I get the SharedPreferences from a PreferenceActivity in Android?
(6 answers)
Closed 7 years ago.
I need simple explanation about shared preference in android and preference data
According to Shared Preferences | Android Developer Tutorial (Part 13) by Sai Geetha M N,
Many applications may provide a way to capture user preferences on the
settings of a specific application or an activity. For supporting
this, Android provides a simple set of APIs.
Preferences are typically name value pairs. They can be stored as
“Shared Preferences” across various activities in an application (note
currently it cannot be shared across processes). Or it can be
something that needs to be stored specific to an activity.
Shared Preferences: The shared preferences can be used by all the components (activities, services etc) off the applications.
Activity handled preferences: These preferences can only be used with in the activity and can not be used by other components of the application.
Shared Preferences:
The shared preferences are managed with the help of getSharedPreferences method of the Context class. The preferences are stored in a default file(1) or you can specify a file name(2) to be used to refer to the preferences.
(1) Here is how you get the instance when you specify the file name
public static final String PREF_FILE_NAME = "PrefFile";
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
MODE_PRIVATE is the operating mode for the preferences. It is the default mode and means the created file will be accessed by only the calling application. Other two mode supported are MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE. In MODE_WORLD_READABLE other application can read the created file but can not modify it. In case of MODE_WORLD_WRITEABLE other applications also have write permissions for the created file.
(2) The recommended way is to use by the default mode, without specifying the file name
SharedPreferences preferences = PreferencesManager.getDefaultSharedPreferences(context);
Finally, once you have the preferences instance, here is how you can retrieve the stored values from the preferences:
int storedPreference = preferences.getInt("storedInt", 0);
To store values in the preference file SharedPreference.Editor object has to be used. Editor is the nested interface of the SharedPreference class.
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
Editor also support methods like remove() and clear() to delete the preference value from the file.
Activity Preferences:
The shared preferences can be used by other application components. But if you do not need to share the preferences with other components and want to have activities private preferences. You can do that with the help of getPreferences() method of the activity. The getPreference method uses the getSharedPreferences() method with the name of the activity class for the preference file name.
Following is the code to get preferences
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
int storedPreference = preferences.getInt("storedInt", 0);
The code to store values is also same as in case of shared preferences.
SharedPreferences preferences = getPreference(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
You can also use other methods like storing the activity state in database. Note Android also contains a package called android.preference. The package defines classes to implement application preferences UI.
To see some more examples check Android's Data Storage post on developers site.
SharedPreferences Example:
package com.example.test;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.Toast;
public class SharedPreferencesDemo extends Activity {
SharedPreferences shared_preferences;
SharedPreferences.Editor shared_preferences_editor;
String test_string = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
shared_preferences = getSharedPreferences("shared_preferences_test",
MODE_PRIVATE);
test_string = shared_preferences.getString("test_key", "Default");
Toast.makeText(getApplicationContext(), test_string, Toast.LENGTH_SHORT)
.show();
shared_preferences_editor = shared_preferences.edit();
shared_preferences_editor.putString("test_key", "Hello World");
shared_preferences_editor.commit();
test_string=shared_preferences.getString("test_key", "Default");
Toast.makeText(getApplicationContext(), test_string, Toast.LENGTH_SHORT).show();
}
}
Here is the post: http://www.codestacks.in/2013/03/sharedpreferences/