CODEWITHSUNDEEP
javaandroidarrayssharedpreferences
mathsislife
mathsislife

Reputation: 57

Remembering the previous array from shared preference

Just a quick question regarding sharedPreferences and int arrays. This is some of my code (the relevant bits). And what I want to happen is if the user does something (keeping it vague because it is not relevant), then the array keeps a 2 in that position. Instead what happens is if everytime I close the app or change the activity, the array goes back to being all ones with no twos. This might be a trivial problem, sorry if it is.

public class SecondActivity extends AppCompatActivity {

    int[] list = { 1, 1, 1, 1, 1, 1 };

public void startAQuestion(View view){ 

    checkAnswerButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) { 

                if(editText2.getText().toString().equals(mAnswer)) {

                    list[tappedQuestionmark]=2; 

                    storeIntArray("updateList", list);

                    Log.i("The array is ", Arrays.toString(list));
                }    
            }
            });
        }

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

        int[] isCorrect = getFromPrefs("updateList");

        Log.i("is Correct is ", Arrays.toString(isCorrect));

    }

    public void storeIntArray(String name, int[] array) {
        SharedPreferences.Editor edit = this
                .getSharedPreferences("com.example.sid.sharedpreferencedemo", Context.MODE_PRIVATE).edit();
        edit.putInt("Count_" + name, array.length).commit();
        int count = 0;
        for (int i : array) {
            edit.putInt("IntValue_" + name + count++, i).commit();
        }
        edit.commit();
    }

    public int[] getFromPrefs(String name) {
        int[] ret;
        SharedPreferences prefs = this.getSharedPreferences("com.example.sid.sharedpreferencedemo",
                Context.MODE_PRIVATE);
        int count = prefs.getInt("Count_" + name, 0);
        ret = new int[count];
        for (int i = 0; i < count; i++) {
            ret[i] = prefs.getInt("IntValue_" + name + i, i);
        }
        return ret;
    }

}

Upvotes: 1

Views: 49

Answers (2)

gabrielkerekes
gabrielkerekes

Reputation: 468

Every time you open the app your list variable gets initialized to all ones. You need to load the list from shared preferences into your list variable not into the isCorrect array, because that is where you take the values from when you update the list stored in shared preferences on the click of a button.

Or in onCreate do:

list = isCorrect;

and I think it should work.

Upvotes: 1

Guilherme Montanher
Guilherme Montanher

Reputation: 101

There are 2 solutions you can try.

Solution 1

make your int array static, and refer to the Activity 

public class SecondActivity extends AppCompatActivity {

   public static int[] list = { 1, 1, 1, 1, 1, 1 };

public void startAQuestion(View view){ 
.
.

How to use

SecondActivity.list[tappedQuestionmark]=2;

Solution 2 use the savedInstance to pass your array

public void onSaveInstanceState(Bundle outState){
    outState.putSerializable("list ", list);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
     list = savedInstanceState.getSerializable("list ");

     if(list  != null)
     {
          //Do something with list 
     }

}

I hope it will help you!

Upvotes: 0

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