Question

我在onPause方法中保存了一个布尔值的状态。我尝试过使用editor.apply（）和editor.commit（），但仍然没有保存这些值。这是onPause方法：

@Override
protected void onPause() {
            SharedPreferences.Editor editor = preferences.edit();
            editor.clear(); //I have tried omitting it
            editor.putBoolean(MUTE_TAG,mute);
            editor.apply(); // I tried editor.commit() but with no effect
            boolean mute1 = preferences.getBoolean(MUTE_TAG,false);
            Log.d(TAG,"Values:\n"+ "mute1 " + mute1 + " mute);
            super.onPause();
        }

注意：当我尝试从不同的活动再次访问SharedPreferences中的值时，它不会更新。这是设置代码

public static boolean mute;
public static final String PREFS = "prefs";
    init(Context context) {
    preferences = context.getSharedPreferences(PREFS,MODE_PRIVATE);
    mute = preferences.getBoolean(MUTE_TAG,false);
        }

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.d(TAG,"MUTE PRESSED");
            mute = isChecked;
            break;
}

Answer 1

What about after saving? Does the logcat show the current/expected value?

Here is what has worked for me:

Before : private boolean mute = true; but after sending the app to background. the result showed it true. While the default value is false;

COPIED YOUR CODE AS-IS

ONLY PROBLEM: Unclosed string literal

    @Override
    protected void onPause() {
        SharedPreferences preferences = getSharedPreferences("SHARED_PREFERENCES_NAME", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = preferences.edit();

        mute = !mute ;
        Log.d(TAG, "UPDATED MUTE VALUE :: " + mute);

        editor.clear(); //I have tried omitting it
        editor.putBoolean(MUTE_TAG,mute);
        editor.apply(); // I tried editor.commit() but with no effect
        boolean mute1 = preferences.getBoolean(MUTE_TAG,false);
        Log.d(TAG,"Values:\n"+ "mute:  " + mute1 + " mute");
        super.onPause();
    }

SOLUTION #2

It is connected to this What's the difference between commit() and apply() in Shared Preference . Try using commit again, commit will block super.onPause from executing thus making sure it saves

SOLUTION #3

Your activities are calling onPause after onCreate thus saving back the default mute value. Therefore, Create a class & add STATIC PUBLIC /PUBLIC STATIC variables that will store the mute value & only save it when an activity is being destroyed. This static variable will not change it's value across activities

SharedPreferences未保存在onPause方法中

1 个答案: