Question

我注意到，在创建片段之后，需要一个元素。在Java中，只需要getActivity()，但在Kotlin中似乎更加困难。 <中的>和mTwoPane = <FragmentActivity>(activity).findViewById(R.id.master_container) != null带红色下划线并返回此错误：

期待元素

class MyFragment() : Fragment() {

    private var mAdapter: MyListAdapter? = null

    internal lateinit var mRecyclerView: RecyclerView

    var mTwoPane: Boolean = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setHasOptionsMenu(true)
    }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        val view = inflater.inflate(R.layout.md, container, false)
        mTwoPane = <FragmentActivity>(activity).findViewById(R.id.master_container) != null

        mRecyclerView = view.findViewById(R.id.recyclerView_list)
        mRecyclerView.setHasFixedSize(true)
        mRecyclerView.layoutManager = LinearLayoutManager(this.activity)        
        mRecyclerView.addItemDecoration(DividerItemDecoration(Objects.requireNonNull<Context>(context), LinearLayout.VERTICAL))

        val myList = ArrayList<Product>()
        val items = resources.getStringArray(R.array.product_names)
        val itemDescriptions = resources.getStringArray(R.array.product_descriptions)
        for (n in items.indices) {
            val product = Product(items[n], itemDescriptions[n])
            myList.add(product)
        }

        mAdapter = MyListAdapter(activity, myList, mTwoPane)
        mRecyclerView.adapter = mAdapter

        return view
    }
}

Answer 1

尝试

mTwoPane = (activity as FragmentActivity).findViewById<View>(R.id.master_container) != null

创建片段后需要元素

1 个答案: