How to carry SharedPreferences into a new function of the same activity? (Android Studio)

Question

I'm using SharedPreferences to create settings on one activity that will be applied on other activities. I've created the SharedPreferences in OnCreate, but then I need to set them in a second function that is called when a button is pressed. At the moment the app keeps crashing on launch if I put SharedPreferences anywhere except for OnCreate.

Problem is I don't seem to be able to carry sharedPreferences into the openNextPage function, as all mentions of it in openNextPage bring up an error saying :

Cannot resolve symbol sharedPreferences

So how can I carry the editor over to this function?

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome_screen);

    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

    Button nextBtn = findViewById(R.id.confSetBtn);
    nextBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            openNextPage();
        }
    });
}

public void openNextPage(){
    SharedPreferences.Editor editor = sharedPreferences.edit();

    if(checkBox1.isChecked()){
        editor.putBoolean("value1", true);
    }
    if(checkBox2.isChecked()){
        editor.putBoolean("value2", true);
    }
    editor.apply();

    boolean none = sharedPreferences.getBoolean("value1", false);

    if(none){
        finish();
    }
    else{
        Intent intent = new Intent(welcomeScreen.this, newSettingsActivity.class);
        startActivity(intent);
    }
}

I think you can declare SharedPrefernces as a field of this class — Humza Malik, Jan 05 '20 at 14:21
@HumzaMalik how would I do that? Still kind of new to android studio — MendelumS, Jan 05 '20 at 14:23
you need to learn java first ... You can declare this variable as a field and initiate in onCreate method.......... if you want to use in another method you can also pass sharedpreferences to that method as reference — Humza Malik, Jan 05 '20 at 14:24

score 1 · Answer 1 · answered Jan 05 '20 at 14:31

You can try it like this i have edited your code. I have declared this as property in your class.

SharedPreferences sharedPreferences;
@Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_welcome_screen);

            sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

            Button nextBtn = findViewById(R.id.confSetBtn);
            nextBtn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    openNextPage();
                }
            });
    }

    public void openNextPage(){
            SharedPreferences.Editor editor = sharedPreferences.edit();

            if(checkBox1.isChecked()){
                editor.putBoolean("value1", true);
            }
            if(checkBox2.isChecked()){
                editor.putBoolean("value2", true);
            }
            editor.apply();

            boolean none = sharedPreferences.getBoolean("value1", false);

            if(none){
                finish();
            }
            else{
                Intent intent = new Intent(welcomeScreen.this, newSettingsActivity.class);
                startActivity(intent);
            }
        }

This solves the issue of the values not passing over to ```openNextPage``` but the app is still crashing on launch. Any ideas why? — MendelumS, Jan 05 '20 at 14:45
@Sam that might be fault in your application code ... Review what you exactly want to do then implement that — Humza Malik, Jan 05 '20 at 15:10

score 0 · Answer 2 · answered Jan 05 '20 at 15:55

0

To access a variable across app declare it as:

public static SharedPreferences object;

Follow this link to understand how to use shared preferences in your app. Link

Cheers!

answered Jan 05 '20 at 15:55

Fahad Bin Asif

66
7

score 0 · Answer 3 · answered Jan 05 '20 at 17:04

Pass instance of SharedPreferences as an argument as follows

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome_screen);

    // update 1
    final SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this); 

    Button nextBtn = findViewById(R.id.confSetBtn);
    nextBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // update 2
            openNextPage(sharedPreferences);  
        }
    });
}

// update 3
public void openNextPage(SharedPreferences sharedPreferences){  
    SharedPreferences.Editor editor = sharedPreferences.edit();

    if(checkBox1.isChecked()){
        editor.putBoolean("value1", true);
    }
    if(checkBox2.isChecked()){
        editor.putBoolean("value2", true);
    }
    editor.apply();

    boolean none = sharedPreferences.getBoolean("value1", false);

    if(none){
        finish();
    }
    else{
        Intent intent = new Intent(welcomeScreen.this, newSettingsActivity.class);
        startActivity(intent);
    }
}

How to carry SharedPreferences into a new function of the same activity? (Android Studio)

3 Answers3