Develop Reference

How to check if clear cache was done by user in android?

The app I am developing should know if the user/android* has cleared cache or clear data , so that I logout the user. How to do this? How to find out if user has cleared cache?
Can the android OS clear the cache of an app by itself (without human intervention)?

Use SharedPreference to store value in Application cache
SharedPreference prefs = getSharedPreferences("UserInfo", 0);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("username", username);
editor.putString("password", password);
editor.commit();
when App started Retrieve data from SharedPreference
SharedPreference prefs = getSharedPreferences("UserInfo", 0);
String username = prefs.getString("username","");
String password = prefs.getString("password","");
if cache is cleared SharedPreference also cleared.so you have to make a condition like if username and password empty means not enter Application.

android cordova sharedpreference deleting during force close

We are facing an issue with android SharedPreferences in our application. Our application is a cordova application. We are storing few data in the SharedPreferences. For example, storing userid, last visited page html contents, few json values.
Following are code samples for managing sharedpreferences (get/set/remove).
//get
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(cordova.getActivity());
Object obj = sharedPrefs.getAll().get(key);
//remove
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(cordova.getActivity());
if (sharedPrefs.contains(key)) {
Editor editor = sharedPrefs.edit();
editor.remove(key);
}
//store
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(cordova.getActivity());
Editor editor = sharedPrefs.edit();
editor.putString(key, value);
editor.commit();
The storing retrieving deleting everything working fine. The problem we are facing is, the data is not persisting in a consistent manner.
For example, user opens the app and then he force close the app, again takes the app. All data in the sharedpreference is persists. But when he force close 2nd time and come back to the app once again, then the data from the sharedpreference is deleted. I could not find any log in the logcat also. Any help will be much appreciated.

How to deal with multi accout login in android?

I have several apps which use the same accout.
The question is when i had more than one apps installed in my phone,how can i login without type username and password if one of the app had logged in.

See below reference code which is having app1 & app2, so using shared preferences suppose you can store username & password in app1 & you can using it in another app2. Here I'm shwing how to access username, you can expand it as per your requirement.
Okay! using this code in Application 1 ( with package name is "com.sharedpref1" ) to store data with Shared Preferences.
SharedPreferences prefs = getSharedPreferences("demopref",
Context.MODE_WORLD_READABLE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("username", strShareValue);
editor.commit();
And using this code in Application 2 to get data from Shared Preferences in Application 1. We can get it because we use MODE_WORLD_READABLE in application 1:
try {
con = createPackageContext("com.sharedpref1", 0);
SharedPreferences pref = con.getSharedPreferences(
"demopref", Context.MODE_PRIVATE);
String data = pref.getString("username", "No Value");
displaySharedValue.setText(data);
} catch (NameNotFoundException e) {
Log.e("Not data shared", e.toString());
}

I think, you could use Database for storing username and password, and share the database among your multiple apps, settings some field like is_logged_in with boolean value 1 when user is loggedin. On app launch, access the database, check for the field is_logged_in and display appropriate logged in view.

How to have android app remember user data/profile?

Making a app that asks user to create a profile, wondering where I should get started in having the app remember this data user inputs? Any tutorials or suggestions would be appreciated.
Thanks,
Grant

I suggest you use SharedPreferences, unless you have a lot of information to store.
After the user successfully logged in, store his information in your Preferences.
For example, to store the username :
private SharedPreferences mPreferences;
mPreferences = getSharedPreferences("User", MODE_PRIVATE);
SharedPreferences.Editor editor = mPreferences.edit();
editor.putString("username", your_user_name);
editor.commit();
Each time the user accesses the login activity, you can check if the username is already stored in the preferences :
if (mPreferences.contains("username")) {
// start Main activity
} else {
// ask him to enter his credentials
}
When the user logs out, don't forget to delete the username key from your preferences :
SharedPreferences.Editor editor = mPreferences.edit();
editor.clear(); // This will delete all your preferences, check how to delete just one
editor.commit();

Insert the data to a SQLite database or use a plain file. The former is recommended for big apps.

Checked out SharedPreferences. Some examples here: SharedPreferences Tutorial
If you only have one user at once and just need to store simple user data like user name, email, id, you can store string/int/... format data in it. Or if you have server for storing user data, you can store credentials in SharedPreference and use the credentials to get data from your server.

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