Kotlin-需要成员声明[重复]

Question

我试图将我的应用程序从Java转换为静态编程语言。

我使用了Android Studio内置转换器并修复了它生成的大部分错误。

对于科特林来说，这一次让我很难受：

我得到了这个用Java编写的类，并进行了转换，显然没有任何错误，这有助于我在回收视图中管理项目点击：

class ItemClickSupport private constructor(private val mRecyclerView: RecyclerView) {
    private var mOnItemClickListener: OnItemClickListener? = null
    private var mOnItemLongClickListener: OnItemLongClickListener? = null
    private val mOnClickListener = View.OnClickListener { v ->
        if (mOnItemClickListener != null) {
            val holder = mRecyclerView.getChildViewHolder(v)
            mOnItemClickListener!!.onItemClicked(mRecyclerView, holder.adapterPosition, v)
        }
    }

    private val mOnLongClickListener = View.OnLongClickListener { v ->
        if (mOnItemLongClickListener != null) {
            val holder = mRecyclerView.getChildViewHolder(v)
            return@OnLongClickListener mOnItemLongClickListener!!.onItemLongClicked(mRecyclerView, holder.adapterPosition, v)
        }
        false
    }

    private val mAttachListener = object : RecyclerView.OnChildAttachStateChangeListener {
        override fun onChildViewAttachedToWindow(view: View) {
            if (mOnItemClickListener != null) {
                view.setOnClickListener(mOnClickListener)
            }
            if (mOnItemLongClickListener != null) {
                view.setOnLongClickListener(mOnLongClickListener)
            }
        }

        override fun onChildViewDetachedFromWindow(view: View) {

        }
    }

    init {
        mRecyclerView.setTag(R.id.item_click_support, this)
        mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener)
    }

    fun setOnItemClickListener(listener: OnItemClickListener): ItemClickSupport {
        mOnItemClickListener = listener
        return this
    }

    fun setOnItemLongClickListener(listener: OnItemLongClickListener): ItemClickSupport {
        mOnItemLongClickListener = listener
        return this
    }

    private fun detach(view: RecyclerView) {
        view.removeOnChildAttachStateChangeListener(mAttachListener)
        view.setTag(R.id.item_click_support, null)
    }

    interface OnItemClickListener {

        fun onItemClicked(recyclerView: RecyclerView, position: Int, v: View)
    }

    interface OnItemLongClickListener {

        fun onItemLongClicked(recyclerView: RecyclerView, position: Int, v: View): Boolean
    }

    companion object {

        fun addTo(view: RecyclerView): ItemClickSupport {
            var support: ItemClickSupport? = view.getTag(R.id.item_click_support) as ItemClickSupport
            if (support == null) {
                support = ItemClickSupport(view)
            }
            return support
        }

        fun removeFrom(view: RecyclerView): ItemClickSupport? {
            val support = view.getTag(R.id.item_click_support) as ItemClickSupport
            support?.detach(view)
            return support
        }
    }
}

在main活动中，转换后在onCreate函数中设置如下：

ItemClickSupport.addTo(recyclerView!!).setOnItemClickListener { recyclerView, position, v ->
            val itemIntent = Intent(this@AddSubscription, CreateSubscription::class.java)

            ...
        }

IDE给我以下错误：

类型不匹配：

必需：ItemClickSupport。OnItemClickListener

发现：（？？？，？？？，？？？）-

现在，我知道单位是Kotlin的void，但我不知道错误在哪里。

按照建议检查了这个答案后，我编写了以下代码：

ItemClickSupport.addTo(recyclerView!!).setOnItemClickListener(
                object: ItemClickSupport.OnItemClickListener {
                    val itemIntent = Intent(this@AddSubscription, CreateSubscription::class.java)
                    val bundle = Bundle()
                    bundle.putParcelable("selected", filteredList!![position])
                    itemIntent.putExtras(bundle)
                    startActivity(itemIntent)
        })

现在我得到了

预期的成员声明

正如在另一个答案中所述，它与构造函数有关。

这是项ClickSupport吗。OnItemClickListener构造函数？如果是，我应该改变什么？

我怀疑错误仍然是由OnClickSupport类被错误地转换为kotlin引起的，即使它没有任何sintax错误

Answer 1

由于您已将这两个文件转换为静态编程语言，并且OnItemClickListener接口是用静态编程语言编写的，因此您不能传递这样的函数lambda。最好的方法是创建接口的匿名实例（您也可以使用lambda，但为了理解起见，我发布的没有lambda）

ItemClickSupport.addTo(recyclerView!!)
    .setOnItemClickListener (object:OnItemClickListener{
        override fun onItemClicked(recyclerView: RecyclerView, position: Int, v: View ){ 
            val itemIntent = Intent(this@AddSubscription, CreateSubscription::class.java)
             ... 
        }
    })

或者，您可以在ItemClickSupport中使用Highorder Function来仅接收lambda并避免接口。