How to access the resource of com.android.internal.R

最近在做一个android player项目，想要默认使用android的internal资源，比如：

com.android.internal.R.layout.media_controller

但是，直接使用会报编译错误：

com.android.internal.R does not exist

You cannot import the internal android class, as the internal.R class isn't visible.

但是可以通过其他的方式来访问，如下：

int mediaControllerId = Resources.getSystem().getIdentifier("media_controller", "layout", "android");

View layout = ((LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(mediaControllerId, this);

同理，可以访问：

mPrevButton = (ImageButton) layout.findViewById(Resources.getSystem().getIdentifier("prev","id", "android"));
mProgress = (ProgressBar) layout.findViewById(Resources.getSystem().getIdentifier("mediacontroller_progress","id", "android"));
mPauseButton = (ImageButton) layout.findViewById(Resources.getSystem().getIdentifier("pause","id", "android"));

getIdentifier的使用方式如下，会返回name对应的id，

Resources.getSystem().getIdentifier(name, defType, defPackage)

而上述name/defType/defPackage如何得到？可以从源码中获得相应的信息