Question

OK here is my problem. I have a spinner and every option in spinner should edit textview in my layout (option in spinner you can see in position command), so I have made it with SharedPreferences, it is not problem, when I select some option in spinner, so the textview is changed, but when I kill my app and then re-open, the textview is default (the same as defined in my layout). So where is the problem?

First Activity:

if(position == 4){
    SharedPreferences myPrefsUv = CPUActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
    SharedPreferences.Editor prefsEditorUv = myPrefsUv.edit();
    prefsEditorUv.putString(maxUv, "1");
    prefsEditorUv.commit();
}

if(position == 5){
    SharedPreferences myPrefsUv = CPUActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
    SharedPreferences.Editor prefsEditorUv = myPrefsUv.edit();
    prefsEditorUv.putString(maxUv, "2");
    prefsEditorUv.commit();
}

if(position == 6){
    SharedPreferences myPrefsUv = CPUActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
    SharedPreferences.Editor prefsEditorUv = myPrefsUv.edit();
    prefsEditorUv.putString(maxUv, "3");
    prefsEditorUv.commit();
}

if(position == 7){
    SharedPreferences myPrefsUv = CPUActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
    SharedPreferences.Editor prefsEditorUv = myPrefsUv.edit();
    prefsEditorUv.putString(maxUv, "4");
    prefsEditorUv.commit();
}

Second Activity:

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_layout);

        SharedPreferences myPrefsUv = UVActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
        String prefNameUv = myPrefsUv.getString(maxUv, "");
        if(prefNameUv == "1"){
            final TextView textUv = (TextView)findViewById(R.id.text_max);
            textUv.setText("100");
        }
        if(prefNameUv == "2"){
            final TextView textUv = (TextView)findViewById(R.id.text_max);
            textUv.setText("110");
        }
        if(prefNameUv == "3"){
            final TextView textUv = (TextView)findViewById(R.id.text_max);
            textUv.setText("120");
        }
        if(prefNameUv == "4"){
            final TextView textUv = (TextView)findViewById(R.id.text_max);
            textUv.setText("130");
        }
    }

Thank you.

Answer 1

You are adding the different values with the same key? This way I think it will always return the first match. I don’t see in your code “maxUv” to be assigned different values, according to the different cases.

1) I suggest you move to if/else construct. This way, when you’re in the right case, the remaining conditions are not evaluated.

2) call the following lines outside the if/else construct. You don’t need to get the SharedPreferences Editor in every case.

SharedPreferences myPrefsUv = CPUActivity.this.getSharedPreferences("myPrefsUv", MODE_PRIVATE);
SharedPreferences.Editor prefsEditorUv = myPrefsUv.edit();

Same for the acquiring of TextView textUv in the second Activity. Just acquire reference once, and use the same reference in all cases.

3) In the second Activity, you’re also comparing Strings with == operator, but Strings should be compared with equals().