Getting started with Android: sharedpreferences

Document directory

• 1. Save
• 2. Read

I. sharedpreferences application scenarios

Sharedpreferences is used to save parameters;

It is saved as an XML file in the/data/package/shared_prefs directory;

Ii. sharedpreferences core code

1. Save

Sharedpreferences preference = context. getsharedpreferences ("xiazdong", context. mode _); // obtain sharedpreferenceseditor editor = preference. edit (); // get the editor. putstring ("name", "value"); // enter the string-type parameter editor. putint ("name", value); // Insert the integer parameter editor. commit (); // submit

2. Read

Sharedpreferences preference = context. getsharedpreferences ("FILENAME", context. mode_private); string name = preference. getstring ("name", "defaultvalue"); // obtain the string type parameter named name. Otherwise, the value is defavaluvalueint age = preference. getint ("name", defaultvalue );

Because this method is very simple, you do not need to explain it here;

Iii. Internal principles we mentioned earlier that sharedpreferences are stored in the/data/shared_prefs directory in XML format. Here we will verify this. If we execute the following statement:

SharedPreferences preference = context.getSharedPreferences("xiazdong", Context.MODE_PRIVATE);Editor editor = preference.edit();editor.putString("name", "xiazdong");editor.putInt("age", 20);editor.commit();

The XML file is as follows:

<?xml version='1.0' encoding='utf-8' standalone='yes' ?><map><string name="name">xiazdong</string><int name="age" value="20" /></map>