[Android存储]Shared Preferences
[引用 http://developer.android.com/guide/topics/data/data-storage.html#pref]
我们可以使用Shared Preferences来存储Key-Values对的私有数据，其中包括：booleans, floats, ints, longs, and strings.但是没有提供Object对象的存储。这些私有数据可以被持久的保存即使应用程序本身被关闭。
1）Shared Preferences提供了2个方法：
a)getSharedPreferences(String name, int mode)
当需要多个 preferences file时需要使用该方法通过名字来定义
b)getPreferences(int mode)
如果只需要使用一个preferences file无需使用名字
c)mode的值：
Activity.MODE_PRIVATE = 0x0000;
where the created file can only be accessed by the calling application
Activity.MODE_WORLD_READABLE = 0x0001;
Allow all other applications to have read access
Activity.MODE_WORLD_WRITEABLE = 0x0002;
Allow all other applications to have write access
2)写入值到preferences file
a)call edit() to get a SharedPreferences.Editor.
b)Add values with methods such as putBoolean() and putString().
c)Commit the new values with commit()
public class Calc extends Activity { public static final String PREFS_NAME = "MyPrefsFile"; @Override protected void onCreate(Bundle state){ super.onCreate(state); . . . // Restore preferences SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); // If only store one preferences file use below method // SharedPreferences settings = getSharedPreferences(0); boolean silent = settings.getBoolean("silentMode", false); setSilent(silent); } @Override protected void onStop(){ super.onStop(); // We need an Editor object to make preference changes. // All objects are from android.context.Context SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); // If only store one preferences file use below method SharedPreferences settings = getSharedPreferences([b][/b]0); SharedPreferences.Editor editor = settings.edit(); editor.putBoolean("silentMode", mSilentMode); // Commit the edits! editor.commit(); }}