I basically have this function that validates the click of the user:
this.btnTryAgain.setOnClickListener {
viewModel.responsePictures.observeForever {
manageResponse(it)
}
clickcount += 1
if (clickcount == 3) {
findNavController().navigate(R.id.errorComprovante)
}
}
The observer is responsible for managing the response of the service. So if the users clicks the button 3 times and it doesn't get any success response, it goes to the errorComprovante.
The problem is that if i use this code with the observer, it simply doesn't work.
Is there a way i can store the number of clicks so that it doesn't get lost? Thanks
Further Reading on Shared Preferences
Store the data in Shared Preferences.
public static final String MyPREFERENCES = "MyPrefs" ;
SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
Editor editor = sharedpreferences.edit();
editor.putInt("count", clickCounter);
editor.commit();
Then get the data from the preferences using
sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE)
You could store the value in a hidden field, that way it would be kept on the client side and would stay as long the the page is not re-rendered.
Shared preferences, database, files. All ways to persist data.
Related
I have 2 int in my navigation drawer, the value of whom changes upon clicking different button on different locations in the app.
I got the code to successfully increment and update them, but the problem is that they got reset when I open the app after closing or exiting it.
How can I make them stay there after getting updated?
If you want any code from my app, then please tell me.
Sorry for bad formatting of the question, but I have no idea how to do this and hence I haven't posted any code.
You must save the info in a persistent storage.
You can use SharedPreferences.
SharedPreferences prefs= getSharedPreferences("aName", MODE_PRIVATE);
//save the value
prefs.edit()
.putInt("nameOfTheValue", theValue).apply();
// get the data
prefs.getInt("nameOfTheValue", aDefaultValue);
You should save them as User SharedPreferences in onDestroy method.
public void onDestroy() {
super.onDestroy();
SharedPreferences settings;
settings = getSharedPreferences("TWO_INT_SAVING", Context.MODE_PRIVATE);
//set the sharedpref
Editor editor = settings.edit();
editor.putInt("FIRST_INT", firstIntValue);
editor.putInt("SECOND_INT", secondIntValue);
editor.commit();
}
And then you can get them back wen needed:
SharedPreferences settings;
settings = getSharedPreferences("TWO_INT_SAVING", Context.MODE_PRIVATE);
//get the sharepref
int firstInt = settings.getInt("FIRST_INT", 0);
int secondInt = settings.getInt("SECOND_INT", 0);
I want to know if its possible to keep information about an app in a while for example.
I have an app that access this file and get information about the choices that the user have made. For example:
I have a button for many events (event is a model), and i want to know if the user clicked in the button even after the application restarts.
I know that it is possible to keep information about login and password. Is possible to do something like this with other information?
Use Shared Preferences. Like so:
Create these methods for use, or just use the content inside of the methods whenever you want:
public String getPrefValue()
{
SharedPreferences sp = getSharedPreferences("preferenceName", 0);
String str = sp.getString("myStore","TheDefaultValueIfNoValueFoundOfThisKey");
return str;
}
public void writeToPref(String thePreference)
{
SharedPreferences.Editor pref =getSharedPreferences("preferenceName",0).edit();
pref.putString("myStore", thePreference);
pref.commit();
}
You could call them like this:
// when they click the button:
writeToPref("theyClickedTheButton");
if (getPrefValue().equals("theyClickedTheButton"))
{
// they have clicked the button
}
else if (getPrefValue().equals("TheDefaultValueIfNoValueFoundOfThisKey"))
{
// this preference has not been created (have not clicked the button)
}
else
{
// this preference has been created, but they have not clicked the button
}
Explanation of the code:
"preferenceName" is the name of the preference you're referring to and therefore has to be the same every time you access that specific preference. eg: "password", "theirSettings"
"myStore" refers to a specific String stored in that preference and their can be multiple.
eg: you have preference "theirSettings", well then "myStore" could be "soundPrefs", "colourPrefs", "language", etc.
Note: you can do this with boolean, integer, etc.
All you have to do is change the String storing and reading to boolean, or whatever type you want.
You can use SharedPreference to save your data in Android.
To write your information
SharedPreferences preferences = getSharedPreferences("PREF", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("user_Id",userid.getText().toString());
editor.putString("user_Password",password.getText().toString());
editor.commit();
To read above information
SharedPreferences prfs = getSharedPreferences("PREF", Context.MODE_PRIVATE);
String username = prfs.getString("user_Id", "");
In iOS NSUserDefaults is used to do the same
//For saving
NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
[defaults setObject:your_username forKey:#"user_Id"];
[defaults synchronize];
//For retrieving
NSString *username = [defaults objectForKey:#"user_Id"];
Hope it helps.
I have 27 characters that I want a player to unlock by beating scores, e.g. if his score is greater than 200 he unlocks character #1. I have a hard time trying to do that.
I have a class for characters that contains its number, the score required to unlock it, and a boolean to check if he is unlocked. But when it comes down to saving, I can't do that.
The main game loop is in file GameScreen. It has a value points counting the score.
When GameState changes to PlayerDead I want to check if any new character has been unlocked, and whether the high score has been beaten to save points.
Please help, I'm struggling with it for over a week and I can't find a good tutorial for SharedPrefs because all of them apply to GUI based activity that saves the name and surname you entered.
if you need sharedPrefs I can help you.
I can give some some example code.
or you can send your code and error if you get one, we update it.
but sharedPrefs is a good idea for that ? if user goes to application settings and clears data of your app, all data will be lost.
why dont you try create a sqlite databade, save it into assets directory and use it?
It's actually pretty simple, you use SharedPreferences to store key-value pairs. You can either call
SharedPreferences mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
From the GameScreen and then define a constant:
public static final String KEY_SCORE = "score";
To use as the key for the saving.
In order to actually save, you need an Editor:
SharedPreferences.Editor mEditor = mPrefs.edit();
//save data now, mPlayerScore is the score you keep track of
//if it's another type call putString(), etc
mEditor.putInt(KEY_SCORE, mPlayerScore);
//if that is the only thing you want for noe
//close and commit
mEditor.commit();
And in order to retrieve the saved score, during your onCreate() you can do:
public void getUserProgress() {
SharedPreferences mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
//no need for an editor when retrieving
mPlayerScore = mPrefs.getInt(KEY_SCORE, 0);
//second value passed was the default score
//if no score was found
}
In order to check for new character s being unlocked, you can call the following code after every game:
private void checkForUserUnlocks() {
if (mPlayerScore >= MyUnlockableCharacter.SCORE_NEEDED_TO_UNLOCK)
MyUnlockableCharacter.isUnlocked = true;
//and same for other unlockabld characters
}
There are other ways to access SharedPreferences, let me know if you need more info.
Use the below code to store and retrieve Score from SharedPreference.
public static void saveScore(Context context, int score){
SharedPreferences sharedPreferences = context.getSharedPreferences("YOUR_PACKAGE_NAME", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt("SCORE", value);
editor.commit();
}
public static int loadScore(Context context){
SharedPreferences sharedPreferences = context.getSharedPreferences("YOUR_PACKAGE_NAME", Context.MODE_PRIVATE);
int score = sharedPreferences.getInt("SCORE", 0);
return score;
}
Read Sample;
public int Read() {
SharedPreferences mSharedPrefs = getSharedPreferences("FileName",
MODE_PRIVATE);
SharedPreferences.Editor mPrefsEditor = mSharedPrefs.edit();
int mCounter = mSharedPrefs.getInt("Counter", 0);
return mCounter;
}
Write Sample;
public void Write() {
SharedPreferences mSharedPrefs = getSharedPreferences("FileName",
MODE_PRIVATE);
SharedPreferences.Editor mPrefsEditor = mSharedPrefs.edit();
mPrefsEditor.putInt("Counter", 15);
mPrefsEditor.commit();
}
I'm a novice Android developer who are currently trying hard to build a Login Screen.
I need to find the easiest way to store the username and password in 1 class and retrieve it from another class. See Google has provided several ways: http://developer.android.com/guide/topics/data/data-storage.html
which one is the most efficient and easy to code?
thanks!
For Login screen tasks like storing username and password you can use Shared Preferences. Here I had made custom methods for using shared preferences. Call savePreferences() method and put your Key and Value(as savePreferences() is based on XML), similarly call Load with your Key. And lastly don't forgot to call deletePreferences() on LOGOUT.
/**
* Method used to get Shared Preferences */
public SharedPreferences getPreferences()
{
return getSharedPreferences(<PREFRENCE_FILE_NAME>, MODE_PRIVATE);
}
/**
* Method used to save Preferences */
public void savePreferences(String key, String value)
{
SharedPreferences sharedPreferences = getPreferences();
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
}
/**
* Method used to load Preferences */
public String loadPreferences(String key)
{
try {
SharedPreferences sharedPreferences = getPreferences();
String strSavedMemo = sharedPreferences.getString(key, "");
return strSavedMemo;
} catch (NullPointerException nullPointerException)
{
Log.e("Error caused at TelaSketchUtin loadPreferences method",
">======>" + nullPointerException);
return null;
}
}
/**
* Method used to delete Preferences */
public boolean deletePreferences(String key)
{
SharedPreferences.Editor editor=getPreferences().edit();
editor.remove(key).commit();
return false;
}
Define some statics to store the preference file name and the keys you're going to use:
public static final String PREFS_NAME = "MyPrefsFile";
private static final String PREF_USERNAME = "username";
private static final String PREF_PASSWORD = "password";
You'd then save the username and password as follows:
getSharedPreferences(PREFS_NAME,MODE_PRIVATE)
.edit()
.putString(PREF_USERNAME, username)
.putString(PREF_PASSWORD, password)
.commit();
So you would retrieve them like this:
SharedPreferences pref = getSharedPreferences(PREFS_NAME,MODE_PRIVATE);
String username = pref.getString(PREF_USERNAME, null);
String password = pref.getString(PREF_PASSWORD, null);
if (username == null || password == null) {
//Prompt for username and password
}
Alternatively, if you don't want to name a preferences file you can just use the default:
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);
For your purpose both, SQLite Database and SharedPreferences will work. But I would suggest SharedPreferences as they are very easy to use. Some ppl like to create a class to hold variables like this but the benefit of SQLite and SharedPreferences file is that the user login name and password information will be with you even if the app goes in background and gets destroyed. So when the user comes back to your app, you can sign them in again without asking for password. If user explicitly decides to logout, you can simply remove the login information from shared preferences file
The easiest way of retrieving log in information from other activities is using "SharedPreferences". I strongly recommend this method for storage and retrieval of Username and Password. Because you can access this information from anywhere in the application without any complications. The log in information may have to use repeatedly in an application.
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 the 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 = PreferenceManager.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.
For more info, check this link:
Making data persistent in android
i am creating login in my app. User type his info i send it to web service to check and get his ID. Now i need to save it somewhere in my app that i could check if he had login.
So where this info should be saved ? I know that every app have it's settings so there should be this info ? Maybe someone could give me more info what and how this is doing.
Thanks.
I found this post:
What is the most appropriate way to store user settings in Android application
I believe my question was duplicate. But it would be nice if you have something to share more.
First of all save user info like uname & password in SharedPreferences with this code.
SharedPreferences settings = getSharedPreferences("UserInfo", 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("Username",txtUname.getText().toString());
editor.putString("Password",txtPWD.getText().toString());
editor.commit();
and then get SharedPreferences from below code
SharedPreferences settings = getSharedPreferences("UserInfo", 0);
txtUname.setText(settings.getString("Username", "").toString());
txtPWD.setText(settings.getString("Password", "").toString());
Answer is Use Application Class or Shared Preferences
I assume you can easily search for the Example of Application Class, SharedPreferences and SQLite Database
So I am mentioning Where Do I Use Which Options
Application Class
When I got anything(var , array , list , objects) to store just only for the LifeTime of the Application..and As it got close (for Android Force Close) I use Application Class.
SharedPreferences
I use this when I got some short information like id,token,username,flags and I want to store that as long as the application rest in the Device..and need to use those information everytime I start the Application..
SQLite Database
When there is a bulk data in Record format (Row - Column) I used it to store in database so it becomes easy to store , retrive and manipulate.
You can use SharedPreferences for this.
Some codes from references (taken from documentation):
public class Calc extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
#Override
protected void onCreate(Bundle state){
super.onCreate(state);
. . .
// Restore preferences
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
boolean silent = settings.getBoolean("silentMode", false);
setSilent(silent);
}
#Override
protected void onStop(){
super.onStop();
// We need an Editor object to make preference changes.
// All objects are from android.context.Context
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean("silentMode", mSilentMode);
// Commit the edits!
editor.commit();
}
}
if user clear the application data from setting -> application manager -> your application -> clear data
then all data saved in shared preferences will get removed