RecyclerView android:layout_width="match_parent"无效

使用RecyclerView 时，在xml文件中设置宽度match_parent无效，解决办法如下：

在Adapter中要如下填充view，

        @Override
	public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
		ViewHolder viewHolder = null;
		LayoutInflater mInflater = LayoutInflater.from(mContext);
		switch (viewType) {
		case FragmentBookShelf.GRID:

                    View view = mInflater.from(mContext).inflate(R.layout.item_grid_bookshelf, parent, false));

                    viewHolder = new GridViewHolder(view);

		    break;
		case FragmentBookShelf.LIST:

                    View view = mInflater.from(mContext).inflate(R.layout.item_list_bookshelf, parent, false));
		    viewHolder = new ListViewHolder(view);
                    break;
		}

		return viewHolder;
	}