try {
            ctx =createPackageContext("com.example.sharetest01",
                    Context.CONTEXT_IGNORE_SECURITY);
        } catch (NameNotFoundException e) {
            Log.e("tag", "没有这个包");
        }
        SharedPreferences sp = ctx.getSharedPreferences("test",
                Context.MODE_WORLD_READABLE|Context.MODE_WORLD_WRITEABLE);
        String value =sp.getString("test", "null");