Attempt to invoke virtual method 'void android.app.ActionBar.setTitle的解决方法

在安卓4.4.2的关于蓝牙开发的一个sample BluetoothChat中，调试时，老是出错：Attempt to invoke virtual method 'void android.app.ActionBar.setTitle

上网查了一下，是这么说的：

（http://www.tuicool.com/articles/IRzUR3M）

The LayoutManager is probably
the most interesting part of theRecyclerView .
This class is responsible for layouting all child views. There isone default implementation available: LinearLayoutManager which
you can use for vertical as well as horizontal lists.

You have to set a LayoutManager for
your RecyclerView otherwise
you will see an exception at Runtime:

所以我就把源代码中的：

private final void setStatus(int resId)

private final void setStatus(CharSequence subTitle)

这两个方法注释掉，就可以正常运行了。