//使用在RV的adapter中的回调里面
//初始化创建匿名接口  回调
 private var mListener: ((a: Int, b: String) -> Unit)? = null
 //.....
  fun setOnItemClickListener(mListener: (position: Int, item: String) -> Unit) {
    this.mListener = mListener
  }
//调匿名回调接口赋值
mListener?.invoke(data, position.toString())
//用
    mineFragmentRvAdapter?.setOnItemClickListener2 { position, item ->
      showToast("$position ==== $item")
    }
**Unit**：无任何返回的类型  相当于Java的void
**invoke**：mListener?.invoke(data, position.toString()) 相当于mListener.data, position.toString()

//创建用于回调接口
        interface OnItemClickListener {
          fun onItemClick(obj: Any?, position: Int)
        }
    //初始化 
       private var mItemClickListener: OnItemClickListener? = null
//方法调用
    fun setOnItemClickListener(itemClickListener: OnItemClickListener) {
        this.mItemClickListener = itemClickListener
    }
//赋值
mItemClickListener.onItemClick(mData[position], position)
//回调调用
  mineFragmentRvAdapter?.setOnItemClickListener(object : OnItemClickListener {
      override fun onItemClick(obj: Any?, position: Int) {
        showToast("$position ==== $obj")
      }
    });
    **Any**：所有没有显式声明基类的class，它的默认父类就是Any；相当于Java中的Object
    **object **：object的作用是调用内部匿名类