Retrieve and hold the contents of the preferences file 'name', returning a SharedPreferences through which you can retrieve and modify its values. Only one instance of the SharedPreferences object is returned to any callers for the same name, meaning they will see each other's edits as soon as they are made.

8.public final String getString (int resId)

Return a localized string from the application's package's default string table.

9.public abstract Object getSystemService (String name)

Return the handle to a system-level service by name. The class of the returned object varies by the requested name. Currently available names are:

還有很多有用的方法，具體不一一列舉。詳情請參考文件，反正Context很有用。