一个项目可能会用到多个RecyclerView，而使用RecyclerView必定离不开Adapter，如果不对Adapter进行封装那么一个项目下来要写多少个Adapter，而这些Adapter代码多数都是一样的。今天来说下RecyclerViewAdapter的封装和使用。

Adapter

abstract class MyRecyclerAdapter<T> constructor(
    private val context: Context,
    list: ArrayList<T>,
    private val resID: Int
): RecyclerView.Adapter<BaseViewHolder>() {
    var data = list

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder {
        val view = LayoutInflater.from(context).inflate(resID,parent,false)
        return BaseViewHolder(view)
    }

    override fun getItemCount(): Int {
       return data.size
    }

    //点击事件
    interface OnItemClickListerner{
        fun onItemClick(position: Int)
    }
    private var mOnItemClickListerner:OnItemClickListerner? = null

    fun setOnItemClickListerner(onItemClickListerner:OnItemClickListerner?){
        mOnItemClickListerner = onItemClickListerner
    }

    override fun onBindViewHolder(
        holder: BaseViewHolder,
        position: Int,
        payloads: MutableList<Any>
    ) {
//        if (payloads.isEmpty()){ // 使用 notifyItemChanged(i,ddd[i]) ，notifyItemChanged(position,payloads) ，使用 notifyDataSetChanged()时 payloads为空
            val item = data[position]
            onBindData(holder,position,item)
//        }else{
//            val item1 = payloads[0]
//            onBindData(holder,position,item1 as T)
//        }
        holder.itemView.setOnClickListener {
            mOnItemClickListerner!!.onItemClick(position)
        }
    }

    override fun onBindViewHolder(holder: BaseViewHolder, position: Int) {
        //不使用
    }

    protected abstract fun onBindData(holder: BaseViewHolder, position: Int, item: T)

    fun Refresh(ddd : ArrayList<T>){
        data = ddd
        if (Looper.myLooper() != Looper.getMainLooper()){
            (context as Activity).runOnUiThread {
//                for (i in ddd.indices){
//                    notifyItemChanged(i,ddd[i])
//                }
                notifyDataSetChanged()
            }
        }
        else{
//            for (i in ddd.indices){
//                notifyItemChanged(i,ddd[i])
//            }
            notifyDataSetChanged()
        }
    }
}

open class BaseViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

}

配置RecyclerView

        rv_test = findViewById(R.id.rv_test)
        //瀑布流
        //1）通过LinearLayoutManager：我们可以实现横向、纵向的列表效果
        //2）通过GridLayoutManager：我们可以实现像GridView一样的网格布局
        //3）通过StaggeredGridLayoutManager：我们可以实现瀑布流的效果
        val layoutManager = StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL)
        //layoutManager.gapStrategy = StaggeredGridLayoutManager.GAP_HANDLING_NONE
        rv_test.layoutManager = layoutManager
        //设置增加或删除条目的动画
        rv_test.setItemAnimator( DefaultItemAnimator())

Adapter使用

       val adapter = object : MyRecyclerAdapter<String>(this,list,R.layout.itemview){
            override fun onBindData(holder: BaseViewHolder, position: Int, item: String) {
                textView = holder.itemView.findViewById(R.id.tv_test)
                imageView = holder.itemView.findViewById(R.id.iv_test)
                textView.text = item
                val params = holder.itemView.layoutParams
                params.height = (if (position % 2 == 0) 2 else 3) * 100 + 60   //设置左右视图为不同的高度
                holder.itemView.layoutParams = params//仅仅改变高度
            }
        }
        rv_test.adapter = adapter
        adapter.setOnItemClickListerner(object : MyRecyclerAdapter.OnItemClickListerner{
            override fun onItemClick(position: Int) {
                Log.e("test","点击了  " + position)
            }
        })
    }

刷新数据

   adapter.Refresh(list)

Adapter 刷新

 fun Refresh(ddd : ArrayList<T>){
        data = ddd
        if (Looper.myLooper() != Looper.getMainLooper()){
            (context as Activity).runOnUiThread {
//                for (i in ddd.indices){
//                    notifyItemChanged(i,ddd[i])
//                }
                notifyDataSetChanged()
            }
        }
        else{
//            for (i in ddd.indices){
//                notifyItemChanged(i,ddd[i])
//            }
            notifyDataSetChanged()
        }
    }

大功告成