BindingAdp (databinding+recyclerview adapter)

优点

代码少，仅仅一个类，功能仅简化，需要更多功能需要自己扩展

数据绑定后，数据变化自动刷新，无需手动刷新（addOnListChangedCallback）

使用方法

class Adp : BindingAdp(R.layout.item) {
        override fun bindData(binding: ItemBinding, data: Bean) {
            binding.bean = data
        }
    }
adp.addHeaderView(headerBinding.root)//添加头view
adp.setData(list)//设置数据源，变量传递

注ItemBinding为databinding下的item布局，Bean为model，bindData中手动为item设置model

BindingAdp.kt

package wine.ls.com.databinding

import android.databinding.DataBindingUtil
import android.databinding.ObservableArrayList
import android.databinding.ObservableList
import android.databinding.ViewDataBinding
import android.os.Handler
import android.os.Looper
import android.os.Message
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.support.v7.widget.StaggeredGridLayoutManager
import android.support.v7.widget.GridLayoutManager


abstract class LBindingAdp(private val layoutRes: Int) : RecyclerView.Adapter() {
    private val hanlder = object : Handler(Looper.getMainLooper()) {
        override fun handleMessage(msg: Message?) {
            super.handleMessage(msg)
            when (msg!!.what) {
                1 -> notifyDataSetChanged()
                2 -> {
                    val strs = msg.obj.toString().split(",")
                    notifyItemRangeChanged(strs[0].toInt(), strs[1].toInt())
                }
                3 -> {
                    val strs = msg.obj.toString().split(",")
                    notifyItemRangeInserted(strs[0].toInt(), strs[1].toInt())
                }
                4 -> {
                    val strs = msg.obj.toString().split(",")
                    notifyItemRangeRemoved(strs[0].toInt(), strs[2].toInt())
                    notifyItemRangeInserted(strs[1].toInt(), strs[2].toInt())
                }
                5 -> {
                    val strs = msg.obj.toString().split(",")
                    notifyItemRangeRemoved(strs[0].toInt(), strs[1].toInt())
                }
            }
        }
    }
    private var list: ObservableArrayList? = null
    private val HEAD = 1111
    private val NORMAL = 2222
    private var headView: View? = null

    fun addHeaderView(view: View) {
        headView = view
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): LBindingVH {
        return if (viewType == HEAD) {
            LBindingVH(headView!!)
        } else {
            LBindingVH(LayoutInflater.from(parent.context).inflate(layoutRes, parent, false))
        }
    }

    fun setData(lis: ObservableArrayList) {
        this.list = lis
        this.list!!.addOnListChangedCallback(callback)
    }

    private var callback: ObservableList.OnListChangedCallback> = object : ObservableList.OnListChangedCallback>() {
        override fun onChanged(sender: ObservableList) {
            hanlder.sendEmptyMessage(1)
        }

        override fun onItemRangeChanged(sender: ObservableList, positionStart: Int, itemCount: Int) {
            val msg = Message()
            msg.what = 2
            msg.obj = "$positionStart,$itemCount"
            hanlder.sendMessage(msg)
        }

        override fun onItemRangeInserted(sender: ObservableList, positionStart: Int, itemCount: Int) {
            val msg = Message()
            msg.what = 3
            msg.obj = "$positionStart,$itemCount"
            hanlder.sendMessage(msg)
        }

        override fun onItemRangeMoved(sender: ObservableList, fromPosition: Int, toPosition: Int, itemCount: Int) {
            val msg = Message()
            msg.what = 4
            msg.obj = "$fromPosition,$toPosition,$itemCount"
            hanlder.sendMessage(msg)
        }

        override fun onItemRangeRemoved(sender: ObservableList, positionStart: Int, itemCount: Int) {
            val msg = Message()
            msg.what = 5
            msg.obj = "$positionStart,$itemCount"
            hanlder.sendMessage(msg)
        }
    }

    override fun getItemCount() = if (headView != null) list!!.size + 1 else list!!.size
    override fun onBindViewHolder(holder: LBindingVH, position: Int) {
        if (null == headView) {
            val binding = DataBindingUtil.getBinding(holder.itemView) as T
            bindData(binding, list!![position])
            binding.executePendingBindings()
        } else {
            if (position > 0) {
                val binding = DataBindingUtil.getBinding(holder.itemView) as T
                bindData(binding, list!![position - 1])
                binding.executePendingBindings()
            }
        }
    }

    override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
        super.onAttachedToRecyclerView(recyclerView)
        val manager = recyclerView.layoutManager
        if (manager is GridLayoutManager) {
            manager.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
                override fun getSpanSize(position: Int): Int {
                    return if (getItemViewType(position) == HEAD)
                        manager.spanCount
                    else
                        1
                }
            }
        }
    }

    override fun onViewAttachedToWindow(holder: LBindingVH) {
        super.onViewAttachedToWindow(holder)
        val lp = holder.itemView.layoutParams
        if (lp != null && lp is StaggeredGridLayoutManager.LayoutParams) {
            lp.isFullSpan = holder.layoutPosition == 0
        }
    }

    abstract fun bindData(binding: T, data: D)

    override fun getItemViewType(position: Int): Int {
        return if (headView != null && position == 0) {
            HEAD
        } else {
            NORMAL
        }
    }

    class LBindingVH(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val binding: ViewDataBinding? = DataBindingUtil.bind(itemView)
    }
}