Android Studio- save object in sharedPreferences [duplicated]

SharedPreferences work the same as a hash table, storing by key / value. These are saved in an XML file in the application folder inside the mobile device.

The Andorid API that you should use is the SharedPreferences .

Form of work:

• The same name must always be used to access them
• There are two forms of access
  • getSharedPreferences (mode) and getSharedPreferences (name, mode)
• There are three access modes:
  • Private (Context.MODE_PRIVATE): Only the application or applications with the same User ID can access these
  • Read (Context.MODE_WORLD_READABLE): Other applications can read them. Very dangerous
  • Writable (Context.MODE_WORLD_WRITEABLE): Other applications can edit them. Very dangerous
• For security, the best thing is that the preferences are private. The other accesses are not recommended by Android.

How to save in them:

• With the SharedPreferences.Editor object we introduce the preferences
• Once entered, you have to save them using the commit () method

• You can save Set objects from API 11

  SharedPreferences preferences = getSharedpreferences("Ejemplo", Context.MODE_PRIVATE);
  SharedPreferences.Editor editor = preferences.edit();
  editor.putBoolean("registrado", true);
  

How to load them:

• To load the preferences we have to use the same name that we use when saving them

• The second parameter indicates the default value that the field takes if the preference does not exist

  SharedPreferences preferences = getSharedpreferences("Ejemplo", Context.MODE_PRIVATE);
  boolean registrado = preferences.getBoolean("registrado", true);