SharedPreferences

存储数据

保存数据一般分为四个步骤：

1. 使用Activity类的getSharedPreferences方法获得SharedPreferences对象
2. 使用SharedPreferences接口的edit获得SharedPreferences.Editor对象
3. 通过SharedPreferences.Editor接口的putXXX方法保存key-value对
4. 通过SharedPreferences.Editor接口的commit方法保存key-value对

读取数据

读取数据一般分为两个步骤：

1. 使用Activity类的getSharedPreferences方法获得SharedPreferences对象
2. 通过SharedPreferences对象的getXXX方法获取数据

总结

1. 通过Activity类的getSharedPreferences方法获得SharedPreferences对象
2. 如果要编辑，则使用edit()方法获取SharedPreferences.Editor对象
3. get或者put
4. 修改后要提交commit()

public static final String PREFS_NAME = "test";

private void saveUserInfo(String name){
    SharedPreferences userInfo = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
    SharedPreferences.Editor editor = userInfo.edit();
    editor.putString("username", name);
    editor.putInt("age", 20);
    editor.commit();//提交修改
}

private String getUserInfo(){
    SharedPreferences userInfo = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
    String username = userInfo.getString("username", "人间几度清明");//读取username
    int age = userInfo.getInt("age", 0);//读取age
    return username;
}

private void removeUserInfo(){
    SharedPreferences userInfo = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
    SharedPreferences.Editor editor = userInfo.edit();//获取Editor
    editor.remove("age");
    editor.commit();
}

private void clearUserInfo(){
    SharedPreferences userInfo = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
    SharedPreferences.Editor editor = userInfo.edit();//获取Editor
    editor.clear();
    editor.commit();
}