I'm trying to create an app for my own use, and I'm trying to save 3 editText boxes to Sharedpref so I can use those values to calculate things later in the app.
Here's the code:
SharedPreferences mSharedPreferences;
private EditText mEditTextBench;
private EditText mEditTextSquat;
private EditText mEditTextDead;
private Button mButton;
public String maxDead = mSharedPreferences.getString("maxDead", "DEFAULT");
Then in the oncreate method I have:
mSharedPreferences= PreferenceManager.getDefaultSharedPreferences(this.getBaseContext());
mButton = (Button) findViewById(R.id.button);
mEditTextBench = (EditText) findViewById(R.id.editTextBench);
mEditTextSquat = (EditText) findViewById(R.id.editTextSquat);
mEditTextDead = (EditText) findViewById(R.id.editTextDead);
and my button onclicklistener:
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences.Editor editor = mSharedPreferences.edit();
editor.putString("maxDead", mEditTextDead.getText().toString());
editor.commit();
If I put the public String maxDead as a final string in the onCreate method, it works, but I want to be able to change the string in the future, using the editText. I don't think I can put it as a final.
The way the code is now, I get this error:
Attempt to invoke interface method 'java.lang.String android.content.SharedPreferences.getString(java.lang.String, java.lang.String)' on a null object reference
your code should be like this.
SharedPreferences mSharedPreferences;
private EditText mEditTextBench;
private EditText mEditTextSquat;
private EditText mEditTextDead;
private Button mButton;
public String maxDead;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
mSharedPreferences= PreferenceManager.getDefaultSharedPreferences(this.getBaseContext());
maxDead = mSharedPreferences.getString("maxDead", "DEFAULT");
mButton = (Button) findViewById(R.id.button);
mEditTextBench = (EditText) findViewById(R.id.editTextBench);
mEditTextSquat = (EditText) findViewById(R.id.editTextSquat);
mEditTextDead = (EditText) findViewById(R.id.editTextDead);
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences.Editor editor = mSharedPreferences.edit();
editor.putString("maxDead", mEditTextDead.getText().toString());
editor.commit();
}
});
}
EDIT : here I am showing my way of using SharedPreference
SharedPreferences myPreference;
String MY_PREFERENCE = "my_preference";
inside onCreate initialise SharedPreference:
myPreference = getSharedPreferences(MY_PREFERENCE, Context.MODE_PRIVATE);
for getting value
String data = myPreference.getString("maxDead", "")
for editing SharedPreference :
SharedPreferences.Editor editor = myPreference.edit();
editor.putString("maxDead", mEditTextDead.getText().toString());
editor.commit();
I hope this will help.
I am also very new to Android but I'll try to answer. The reason why you are getting the exception is because when the Activity is created there is nothing in the String maxDead, given it is assigned on the top as private String maxDead. You only assign a value to it when you click your button. Where do you want to use this value? I can't comment yet, that's why I am writing this in an answer. :(
This is an example of how I use SharedPreferences:
SharedPreferences spref = getSharedPreferences("MY_PREFS", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = spref.edit();
editor.putString("maxDead", mEditTextDead.getText().toString());
editor.apply;
And then somewhere (another activity/fragment) where you need the value:
String maxDead = spref.getString("maxDead", "");
You're getting the error because of this :
public String maxDead = mSharedPreferences.getString("maxDead", "DEFAULT");
as you've not initialized mSharedPreferences so, its throwing NullPointerException.
change this to :
public String maxDead;
and then initialize maxDead in your onCreate method after you initialize mSharedPreferences :
maxDead = mSharedPreferences.getString("maxDead", "DEFAULT");
UPDATE
You're not getting the updated value of the maxDead inside the onClickListener as the value of the variable maxData is set only once in the onCreate. So the variable is not updated when the value of maxData is updated in the SharedPreferences. So, instead of keeping a variable you should use a method like this to get the latest value from the SharedPreference :
private String getMaxDead(){
if(mSharedPreferences == null)
mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this.getBaseContext());
return mSharedPreferences.getString("maxDead", "DEFAULT");
}
So use : getMaxDead() in your toast and it will work.
Related
I'm trying to save textview from getIntent String. When I close the application, then open again, textview is null. I have used many methods like onSaveInstance, SharedPreference but all failed.
Code :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
jamShubuh = findViewById(R.id.jamShubuhTextView);
jamDzuhur = findViewById(R.id.jamDzuhurTextView);
jamAshar = findViewById(R.id.jamAsharTextView);
getShubuh = getIntent().getStringExtra("getShubuh");
getDzuhur = getIntent().getStringExtra("getDzuhur");
getAshar = getIntent().getStringExtra("getAshar");
jamShubuh.setText(getShubuh);
jamDzuhur.setText(getDzuhur);
jamAshar.setText(getAshar);
SharedPreferences sharedPreferences = getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("shubuh", getShubuh);
editor.putString("dzuhur", getDzuhur);
editor.putString("ashar", getAshar);
retriveData();
private void retriveData() {
SharedPreferences getData = getPreferences(Context.MODE_PRIVATE);
getData.getString("shubuh", null);
getData.getString("dzuhur", null);
getData.getString("ashar", null);
}
To use the shared preferences, I suggest you to make certain class to handle it. Maybe like this.
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
public class MyPrefManager {
SharedPreferences sp;
SharedPreferences.Editor editor;
public void setPref(Context context, String key, String value){
sp = PreferenceManager.getDefaultSharedPreferences(context);
editor = sp.edit();
editor.putString(key, value);
editor.commit();
}
public String getPref(Context context, String key){
sp = PreferenceManager.getDefaultSharedPreferences(context);
value = null;
String X = sp.getString(key, value);
return X;
}
}
Then use setPref method to set the value and getPref method to get the value. Assume now you are in MainActivity and you want to save values of getShubuh, getDzuhur, and getAshar to Preference Manager, you can do something like this :
MyPrefManager MPM = new MyPrefManager();
MPM.setPref(MainActivity.this,"keyShubuh",getShubuh);
MPM.setPref(MainActivity.this,"keyDzuhur",getDzuhur);
MPM.setPref(MainActivity.this,"keyAshar",getAshar);
And to get the value of keyShubuh, keyDzuhur, and keyAshar wherever you want, you can do something like this.
MyPrefManager MPM = new MyPrefManager();
MPM.getPref(AnyActivity.this,"keyShubuh");
MPM.getPref(AnyActivity.this,"keyDzuhur");
MPM.getPref(AnyActivity.this,"keyAshar");
Hope it can help.
To save text state
//Saving The Text Entered by User
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
editText = findViewById(R.id.editText);// getting the reference of editext from xml
CharSequence text = editText.getText();// getting text u entered in edittext
outState.putCharSequence("savedText", text);// saved that text in bundle object i.e. outState
}
and restore saved text
//Restoring the State
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
editText = findViewById(R.id.editText);// getting the reference of textview from xml
CharSequence savedText =
savedInstanceState.getCharSequence("savedText");// getting the text of editext
editText.setText(savedText);// set the text that is retrieved from bundle object
}
instead of EditText you can use TextView.
I would like to know how I can store a boolean with SharedPreferences and disable a button. If you restart the app, the button should remain disabled.
Here is my Code, but something is wrong.
public class Pass extends AppCompatActivity implements View.OnClickListener {
private Button btn1;
private EditText text1;
private SharedPreferences speicher;
private SharedPreferences.Editor editor;
final boolean enabled = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pass);
btn1 = (Button) findViewById(R.id.button);
btn1.setOnClickListener(this);
text1 = (EditText) findViewById(R.id.editText);
text1.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);
speicher = getApplicationContext().getSharedPreferences("Daten", 0);
editor = speicher.edit();
speicher = getSharedPreferences("Daten", 0);
speicher.getBoolean("Data1", enabled);
}
public void onClick (View view){
if (text1.getText().toString().equals("pass")){
AlertDialog ad = new AlertDialog.Builder(this).create();
ad.setMessage("Great");
ad.show();
Intent intent = new Intent(this,Popup.class);
startActivity(intent);
btn1.setEnabled(enabled);
editor.putBoolean("Data1", enabled);
editor.commit();
}else{
String message = "Wrong";
Toast.makeText(this,message, Toast.LENGTH_LONG).show();
}
}
}
I hope you can help me.
since
Strecki
You're not checking the condition to enable or disable button that you're getting from SharedPreference. Do something like this:
btn1.setEnabled(speicher.getBoolean("Data1", enabled));
Try this one it will work.
Remove this line on your code. Because initialized again here.
"speicher = getSharedPreferences("Daten", 0);"
You have to try like this
SharedPreferences speicher = getApplicationContext().getSharedPreferences("Daten", 0);
SharedPreferences.Editor editor = speicher.edit();
Store the value like this
editor.putBoolean("Data1", true); editor.commit();
Get value like this
Boolean result = speicher.getBoolean("Data1", false); //false is default value.
I am using shared preferences but my code is not working. I don't know what's wrong with it. Am I implementing something wrong?
My main java activity(relevant bit of code) is:
public class MainActivity extends AppCompatActivity {
private String s;
public static final String subjectKey = "SubjectID";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final SharedPreferences sharedPreferences = getSharedPreferences(subjectKey, Context.MODE_PRIVATE);
TextView calc_monday = (TextView) findViewById(R.id.monday_calc);
calc_monday.setOnClickListener(
new Button.OnClickListener(){
public void onClick(View v){
CustomDialogClass cdd = new CustomDialogClass(MainActivity.this);
cdd.show();
TextView text1 = (TextView) cdd.findViewById(R.id.Subject_ID);
String text = sharedPreferences.getString(subjectKey, " ");
if(text != " ")
{
text1.setText(text); /* Edit the value here*/
}
TextView text2 = (TextView) cdd.findViewById(R.id.Room_ID);
text2.setText("6 (SEECS)");
TextView text3 = (TextView) cdd.findViewById(R.id.Time_ID);
text3.setText("09:00am - 09:50am");
}
}
);
calc_monday.setOnLongClickListener(
new Button.OnLongClickListener() {
public boolean onLongClick(View v) {
SettingDialogClass SDC = new SettingDialogClass(MainActivity.this);
SDC.show();
EditText texii = (EditText) SDC.findViewById(R.id.set_Subject_ID);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(subjectKey, texii.getText().toString());
editor.apply();
return true;
}
}
);
Basically I want that when I longClick a textbox (calc_monday), a dialog box should appear which appears. Now I should be able to write something on the EditText field which appears on this dialog box. Whatever I write should be stored and then displayed when I SINGLE CLICK on the same textbox (calc_monday)
Please see the 2 methods: onClick and onLongClick to understand.
The code is not working, i.e the text I write on EditText field on onLongCLick dialog box is not being displayed when I single click on the textbox.
What's wrong with the code
When you long press calc_monday, it just show your custom dialog with empty value for EditText. To save your text when input in EditText, create a button in your custom dialog, and call onClickListener action for this button, then save value to SharePreferences.
calc_monday.setOnLongClickListener(
new Button.OnLongClickListener() {
public boolean onLongClick(View v) {
SettingDialogClass SDC = new SettingDialogClass(MainActivity.this);
EditText texii = (EditText) SDC.findViewById(R.id.set_Subject_ID);
Button btnSave = (Button)SDC.findViewById(R.id.your_custom_button);
btnSave.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(subjectKey, texii.getText().toString());
editor.apply();
SDC.dismiss();
}
});
SDC.show();
return true;
}
}
);
I think it's should be :
String text = sharedPreferences.getString("Name", " ");
Try these methods for saving and loading Strings with preferences:
//save prefs
public void savePrefs(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
}
//get prefs
public String loadPrefs(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String data = sharedPreferences.getString(key, value);
return data;
}
You can call the load method like this:
subjectKey = loadPrefs("YouCanNameThisAnything", subjectKey);
And you can call the save method like this:
savePrefs("YouCanNameThisAnything", subjectKey);
More details on how to use shared preferences is also available in the documentation here:
http://developer.android.com/reference/android/content/SharedPreferences.html
//create and initialize the intance of shared preference
SharedPreferences sharedPreferences = getSharedPreferences("Session", MODE_PRIVATE);
//save a string
SharedPreferences.Editor edit = sharedPreferences.edit();
edit.putString(subjectKey , texii.getText().toString());
edit.commit();
//retrieve the string
String subject = sharedPreferences.getString(subjectKey, "");
I have two different activity's. First one only showed to the user first time - to store phonenumber inside sharedprefs. I think the problem is my load from prefs method but just in case I will leave everything here to make it more relevant to future users. It looks like in both activitys the "mobilnummer" is saved - but I am having problem to display them.
The idea is it to be overwritten if user updates it - I think the method will do that?
OnStartUp.java
public static final String PREFS_NAME = "MobileNumberSaved";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mobilnummer = (EditText) findViewById(R.id.mobilnummer);
final Button button = (Button) findViewById(R.id.ntonboarding);}
public void SaveToMobile(View v) {
if (mobilnummer.getText().toString().length() >= 8) {
FragmentedUser.SaveMobile(mobilnummer.getText().toString()); // just saves to Parse.com (This works)
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("mobilnummer", mobilnummer.toString());
editor.commit();
}
}
Profile
EditText mobilnummer;
public static final String PREFS_NAME = "MobileNumberSaved";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mobilnummer = (EditText) findViewById(R.id.mobilnummer);
This is the issue/problem i think! (Code below)
SharedPreferences MobileNumberSaved = this.getSharedPreferences("mobilnummer", Context.MODE_PRIVATE);
String tempMobilnummer = mobilnummer.getText().toString();
mobilnummer.setText(tempMobilnummer);
// IF user wants to change mobilenumber
mobilnummer.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
if (mobilnummer.getText().toString().length() >= 8)
FragmentedUser.SaveMobile(mobilnummer.getText().toString());
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("mobilnummer", mobilnummer.toString());
editor.commit();
tlfstatus.setImageResource(R.drawable.ok);
handled = true;
}
return handled;
}
});
I think here is your error:
SharedPreferences MobileNumberSaved = this.getSharedPreferences("mobilnummer", Context.MODE_PRIVATE);
//here it should be MobileNumberSaved instead of mobilnummer, because tehre is no sense to set the same text to the textView again after you got it from there
String tempMobilnummer = MobileNumberSaved.getText().toString();
mobilnummer.setText(tempMobilnummer);
But the correct way to get a value from shared preferences is something like this:
SharedPreferences prefs = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
String savedMobileNumber = prefs.getString("mobilnummer", "");
mobilnummer.setText(savedMobileNumber);
Update: when you save the value in the shared preferences, you save only the editText, not it's value, so do something like this when saving:
SharedPreferences.Editor editor = settings.edit();
//mobilnumber is your EditText, so get it's text like this
editor.putString("mobilnummer", mobilnummer.getText().toString());
editor.commit();
And everything else is still the same that I wrote above
I have a configuration page which has a form on it. When the button is pressed, I want to save that value to a SharedPreference. This SharedPreference value then needs to be accessed from elsewhere in my app.
I am trying to save the value like the below. I want to save the collectionID so I can use it elsewhere
public class ConfigPage extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
Button mButton;
EditText mEdit;
String collectionID;
String key = "GregKey";
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config);
getActionBar().hide();
mButton = (Button)findViewById(R.id.setCollection);
mEdit = (EditText)findViewById(R.id.collectionName);
mButton.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
SharedPreferences settings =
getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, collectionID);
editor.commit();
}
});
}
}
Once it has been saved, I then need to access it in another class, however I can't figure out how to do this. The example above crashes the application at the moment so something isn't quite right
I want to save the collectionID so I can use it elsewhere
Use mButton Button onClick event for saving EditText text in SharedPreferences as :
mButton.setOnClickListener( new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
// save value here in SharedPreferences
SharedPreferences settings =
ConfigPage.this.getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(collectionID, collectionID);
editor.commit();
}
});
Your crash occurs because your value is null:
String savedID;
You need to add a value to the variable:
String savedID = "somevalue";
Also, your key is null as long as the Button is not pressed which will also lead to a crash.
The putString(String key, String value) method enables you to store a specific value with a specific key, that can later be used to reaccess the stored value.
Example:
String key = "somekey";
String value = "yourvaluetostore";
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value); // store the value
editor.commit();
In another Activity:
String key = "somekey";
SharedPreferences sharedPreferences = getSharedPreferences(PREFS_NAME, 0);
// get the value "" is default
String value = sharedPreferences.getString(key, "");
All you need in the other Activity is the key you stored the value with. With this key, you can pull the correct stored value out of the SharedPreferences. --> The key is needed to identify the value.
Since you are using the part of code :
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(collectionID, savedID);
editor.commit();
Log.d("Saved as", savedID);
in the onCreate method, that translates to
...
editor.putString(null, null);
Log.d("Saved as", null);
Correct your code so that you fill those elements before. I guess you wanted to make the save in the OnClick part
Yes something its not quite right here because as i see you are saving nothing. on shared pref you should have a "key" which will be use to identify the saved value in your example it should be something like this
public class ConfigPage extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
public static final String COLLECTIONID_KEY = "COLLECTIONID_KEY";
Button mButton;
EditText mEdit;
String collectionID;
String savedID;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config);
getActionBar().hide();
mButton = (Button)findViewById(R.id.setCollection);
mEdit = (EditText)findViewById(R.id.collectionName);
mButton.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
}
});
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(COLLECTIONID_KEY, collectionID);
editor.commit();
Log.d("Saved as", COLLECTIONID_KEY);
}
}
then to retrieve it :
SharedPreferences sharedPreferences = getSharedPreferences(PREFS_NAME, 0);
String mySavedCollectionID = sharedPreferences.getString(COLLECTIONID_KEY);
and make sure that its done on the Onclick event otherwise you might end up with crash again because after the on-click event in your code the lines below will run anyway and save null!