how to set a shared preference

Question

I am trying to set a shared preference but the below code results in false on both occasions.

I first get the value of the flag when it doesn't exist and expect a false . However, then I set the value to true and fetch the flag again and this time I expect true but it is still false .

    SharedPreferences sharedPref = getSharedPreferences("myapp",0);
    //fetch value when it does not exist
    Boolean mobileFlag = sharedPref.getBoolean("mobile_flag", false);
    Log.d("mobileFlag1", mobileFlag+"");
    //set the value
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putBoolean("mobile_flag",true);
    //fetch value when it has been set. 
    mobileFlag = sharedPref.getBoolean("mobile_flag", false);
    Log.d("mobileFlag2", mobileFlag+"");

both times the results of the log messages is:

D/mobileFlag1﹕ false
D/mobileFlag2﹕ false

Answer 1

您未提交新值

editor.putBoolean("mobile_flag",true).commit();

Answer 2

在SharedPreferences中完成变量的编辑后，需要提交更改。

editor.commit();

Answer 3

after using editor.putBoolean("mobile_flag",true); you need to put editor.commit() . This will save your sharedPreference otherwise nothing will be saved.