Android使用Kotlin实现多节点进度条

package com.example.lee.linenode
import android.annotation.SuppressLint
import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v7.widget.LinearLayoutManager
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.android.synthetic.main.item_line_node.view.*
class MainActivity : AppCompatActivity() {
 private var list = arrayListOf<StepBean>()
 private var lineNodeAdapter: LineNodeAdapter<StepBean>? = null
 override fun onCreate(savedInstanceState: Bundle?) {
 super.onCreate(savedInstanceState)
 setContentView(R.layout.activity_main)
 initRecyclerView()
 }
 private fun initRecyclerView() {
 getData()
 //创建一个继承于抽象类(LineNodeAdapter)的实例
 lineNodeAdapter = object : LineNodeAdapter<StepBean>(this, list) {
  override fun convert(viewHolder: LineNodeViewHolder, t: StepBean) {
  viewHolder.itemView.title_txt.text = t.title
  viewHolder.itemView.time_txt.text = t.time
  viewHolder.itemView.num_txt.text = t.num.toString()
  if (t.num == 1) {
   if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
   viewHolder.itemView.left_view.background = null
   }
  }
  if (t.num == 4) {
   if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
   viewHolder.itemView.right_view.background = null
   }
  }
  if (t.num < 3) viewHolder.itemView.num_txt.setBackgroundResource(R.drawable.shap_line_number_circle_red)
  }
 }
 val linearLayoutManager = LinearLayoutManager(this)
 linearLayoutManager.orientation = LinearLayoutManager.HORIZONTAL
 //使用来自主代码集的 R.layout.activity_main,而不是 findViewById(R.id.ln_recycler_view) as Recyclerview
 ln_recycler_view.layoutManager = linearLayoutManager
 ln_recycler_view.adapter = lineNodeAdapter
 }
 private fun getData() {
 for (i in 1..4) {
  list.add(StepBean(i, "2017-9-27\n17:1$i", "步骤$i"))
 }
 }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
 <android.support.v7.widget.RecyclerView
 android:id="@+id/ln_recycler_view"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_centerHorizontal="true" />
</RelativeLayout>

package com.example.lee.linenode
import android.content.Context
import android.support.v7.widget.RecyclerView
import android.support.v7.widget.RecyclerView.Adapter
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import kotlinx.android.synthetic.main.item_line_node.view.*
/**
 * Created by lee on 17-9-27.
 */
abstract class LineNodeAdapter<T>(val context: Context, val list: List<T>) : Adapter<LineNodeAdapter.LineNodeViewHolder>() {
 override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): LineNodeViewHolder {
 return LineNodeViewHolder(LayoutInflater.from(context).inflate(R.layout.item_line_node, parent, false))
 }
 override fun onBindViewHolder(viewHolder: LineNodeViewHolder, position: Int) {
 convert(viewHolder, list.get(position))
 }
 abstract fun convert(viewHolder: LineNodeViewHolder, t: T)
 override fun getItemCount(): Int {
 return list.size
 }
 class LineNodeViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:gravity="center_horizontal"
 android:orientation="vertical">
 <TextView
 android:id="@+id/title_txt"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:text="步骤" />
 <LinearLayout
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:gravity="center_vertical"
 android:orientation="horizontal">
 <View
  android:id="@+id/left_view"
  android:layout_width="30dp"
  android:layout_height="1dp"
  android:layout_centerVertical="true"
  android:background="#A6A6A6" />
 <TextView
  android:id="@+id/num_txt"
  android:layout_width="20dp"
  android:layout_height="20dp"
  android:background="@drawable/shap_line_number_circle_grey"
  android:gravity="center"
  android:text="1"
  android:textColor="@color/colorWhite" />
 <View
  android:id="@+id/right_view"
  android:layout_width="30dp"
  android:layout_height="1dp"
  android:layout_centerVertical="true"
  android:background="#A6A6A6" />
 </LinearLayout>
 <TextView
 android:id="@+id/time_txt"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:gravity="center_horizontal"
 android:text="2017-09-27\n15:56" />
</LinearLayout>

package com.example.lee.linenode
/**
 * Created by lee on 17-9-27.
 */
class StepBean(var num: Int, var time: String, var title: String)//直接在主构造函数里声明属性