读写自定义的数据：
ContentResolver cr = context.getContentResolver();
android.provider.Settings.System.putInt(cr, "i_name", 88);
int i = android.provider.Settings.System.getInt(cr, "i_name");
需要权限：
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
Allows an application to read or write the system settings.
