I load from activity A the SharedPreferences in following way:
private void SavePreferences(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
}
At activity B I want to load the SharedPreferences. Following was a NullPointerException:
private void LoadPreferences(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
data = sharedPreferences.getString("name", "08:00") ;
}
If I try following, I get this compilation error: "No enclosing instance of the type A is accessible in scope"
private void LoadPreferences(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(A.this);
data = sharedPreferences.getString("name", "08:00") ;
}
How can I access the data?
use getApplicationContext() instead of this in both Activities as:
In activity A the SharedPreferences in following way:
private void SavePreferences(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
Intent sd=new Intent(this,Secongtess.class);
startActivity(sd);
}
and in Activity B get Value as:
private void LoadPreferences(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String data = sharedPreferences.getString("name", "08:00") ;
Toast.makeText(this,data, Toast.LENGTH_LONG).show();
}
because as doc says:
getDefaultSharedPreferences(Context context) :
Gets a SharedPreferences instance that points to the default file that
is used by the preference framework in the given context.
Related
Hy, I'm writing an application for a project. I'm trying to pass data between two activities. I tried to use the SharedPreference but it's doesn't work. The output send me always " ".
I post the two function below.
function for send data:
public void SaveUser(FirebaseUser user){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(TEXT, user.getDisplayName());
}
function for get data:
public String ReturnCreatorName(){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
String name = sharedPreferences.getString(TEXT, "");
return name;
}
you forgot editor.commit();
public void SaveUser(FirebaseUser user){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(TEXT, user.getDisplayName());
editor.commit();
}
I use SharedPreferences in my app to save small Integer data . But I get ClassCastException in this line .
int number = mySharedPref.getInt("numberOne",0);
Here is my code .
To store data .
mySharedPref=getSharedPreferences("MyPref",Context.MODE_PRIVATE);
SharedPreferences.Editor editor = mySharedPref.edit();
editor.putInt("numberOne",myInteger);
To get data
mySharedPref = getSharedPreferences("MyPref",Context.MODE_PRIVATE);
int number= mySharedPref.getInt("numberOne",0);
display(number);
I think the problem is that you have not committed the data stored in SharedPreferences.
So you should do a
editor.commit();
while storing the data.
Try this
To Store data
public static void setInteger(Context context, String key, Integer Value) {
sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(context);
SharedPreferences.Editor sEdit = sharedPreferences.edit();
sEdit.putInt(key, Value);
sEdit.commit();
}
To get data
public static Integer getInteger(Context context, String key) {
sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(context);
Integer value = sharedPreferences.getInt(key, 0);
return value;
}
You have to call commit() method to save data changes in SharedPreferences.
Here is the get data method
private void showData() {
SharedPreferences sharedPreferences = getSharedPreferences("MyFile", Context.MODE_PRIVATE);
int number = sharedPreferences.getInt("numberOne", 0);
display(number);
}
Here is get savemethod
private void saveData(int value) {
SharedPreferences sharedPreferences = getSharedPreferences("MyFile", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt("numberOne", value);
editor.commit();
}
This Is The Code When I save My Value
public static final String
MyPREFERENCES = "MyPrefs" ;
public SharedPreferences sharedpreferences;
public static final String p = "pickLoc";
public static final String Phone = "dropLoc";
String pickLoc = pickupEt.getText().toString().trim();
String dropLoc = dropEt.getText().toString().trim();
sharedpreferences = getSharedPreferences(BookMyRide.this.MyPREFERENCES,
Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(p, pickLoc);
editor.putString(Phone, dropLoc);
editor.commit();
This Is The Code When i Want to Get Value
try{
sharedpreferences = getSharedPreferences(MyPREFERENCES,Context.MODE_PRIVATE);
sharedpreferences.getString("pickLoc" ,"");
sharedpreferences.getString("dropLoc","");
}catch (Exception e){
e.printStackTrace();
}
Then it Throws the Exception :
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.SharedPreferences android.content.Context.getSharedPreferences(java.lang.String, int)' on a null object reference
Thanks In Advance For Helping Me
Check this
The Context in your activity may be null
SharedPreference without PreferenceManager !!!
Check this sample
To save urValue in SharedPreferences:
SharedPreferences sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(this);
Editor editor = sharedPreferences.edit();
editor.putString(key, urValue);
editor.apply();
To get name from SharedPreferences:
SharedPreferences sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(this);
String urValue = sharedPreferences.getString(key, "default value");
For more check this link
Writing preference from file Login.java:
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(Login.this);
SharedPreferences.Editor edit = sp.edit();
edit.putString("username", username);
edit.commit();
Loading preference in UpdateList.java:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(UpdateList.this);
String post_username = sp.getString("username", "anon");
I want to pass this shared preference to a php file through json, but it is not able to save the preference across two activities
Try this code to access and write your SharePreference
public static final String PREF_FIELD = "name";
public String getText(Context context) {
SharedPreferences preferences = context.getSharedPreferences(
"GLOBAL",
Context.MODE_PRIVATE);
String sessionId = preferences.getString(
PREF_FIELD,
"");
return sessionId;
}
public void setText(Context context, String text) {
SharedPreferences preferences = context.getSharedPreferences(
"GLOBAL",
Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(PREF_FIELD, text);
editor.commit();
}
How to save TextView values in SharedPreferences, see my code below and let me know how to store to SharedPreferences and retrieve in onCreate(..)
my code looks like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
txtOperative = (TextView) findViewById(R.id.currentOperative);
txtEvent = (TextView) findViewById(R.id.currentEvent);
intent = getIntent();
strEventName = intent.getStringExtra("eventName");
strOperativeName = intent.getStringExtra("operativeName");
txtEvent.setText(strEventName);
txtOperative.setText(strOperativeName);
}
I want to show these values always in TextViews, whenever user comes back to this activity
Simple use this for save your TextView value in sharedpreference
SharedPreferences sp = getSharedPreferences("key", 0);
SharedPreferences.Editor sedt = sp.edit();
sedt.putString("textvalue", txtEvent.getText().toString());
sedt.putString("txtopertaive", txtOperative.getText().toString());
sedt.commit();
Now after that retrieve it anywhere in your Activity class or any other Activity by
SharedPreferences sp = getSharedPreferences("key", 0);
String tValue = sp.getString("textvalue","");
String tOperative = sp.getString("txtopertaive","");
To save the data, Can't see any call for SharedPreferences - editor/ editor.commit()
Add those functions to your activity:
When you want to save data:
saveDataToPreferences(context, "strEventName", valueHere);
And in your activity,
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
context=this;
txtOperative = (TextView) findViewById(R.id.currentOperative);
txtEvent = (TextView) findViewById(R.id.currentEvent);
intent = getIntent();
strEventName = intent.getStringExtra("eventName");
strOperativeName = intent.getStringExtra("operativeName");
txtEvent.setText(getDataFromPreferences(context,"strEventName"));
txtOperative.setText(getDataFromPreferences(context,"strEventName"));
}
public static void saveDataToPreferences(Context context, String key,
String value) {
SharedPreferences prefs = context.getSharedPreferences("your package name",
Context.MODE_PRIVATE);
Editor editor = prefs.edit();
editor.putString(key, value);
editor.commit();
}
public static String getDataFromPreferences(Context context, String key) {
SharedPreferences prefs = context.getSharedPreferences("your package name",
Context.MODE_PRIVATE);
return prefs.getString(key, Constants.BLANK);
}
To store in shared preferences your value use that code.
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
editor.putString("OPERATIVE", txtOperative.getText().toString());
editor.String("EVENT", txtEvent.getText().toString());
editor.commit();
Use
prefs.edit().putString(context.getString(R.string.NAME), name).commit();
in order to save data to shared preferences and
prefs.getString(context.getString(R.string.NAME), "");
to get data from shared preferences.
define Editor like below
private Editor editor;
and initialize it after initializing shared preference like
editor = prefs.edit();
editor.putString("key1", "value1");
editor.putString("key2", "value2");
editor.commit();
And to retrieve this value just call
String value = prefs.getString("key1","");