[移动开发]ViewPager2 入门demo

直接上代码，采用kotlin编写。
Activity 源码如下：

package com.canbot.u05.activity

import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.fragment.app.FragmentActivity
import androidx.recyclerview.widget.RecyclerView
import androidx.viewpager2.widget.ViewPager2
import com.canbot.u05.R
import com.canbot.u05.activity.Splash.CustomAdapter.ViewHolder
import kotlinx.android.synthetic.main.splash.*

/**
 */
class Splash : FragmentActivity() {

    class Callback : ViewPager2.OnPageChangeCallback() {
        override fun onPageScrolled(
            position: Int,
            positionOffset: Float,
            positionOffsetPixels: Int
        ) {

        }

        override fun onPageSelected(position: Int) {
            Log.d(TAG, "onPageSelected $position")

        }

        override fun onPageScrollStateChanged(state: Int) {

        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.splash)
        val names = arrayOf("1", "2", "3","4","5","6")
        pager.adapter = CustomAdapter(names)
        pager.registerOnPageChangeCallback(Callback())
    }

    class CustomAdapter(private val dataSet: Array<String>) : RecyclerView.Adapter<ViewHolder>() {

        class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
            val textView: TextView = view.findViewById(R.id.textView) as TextView
        }

        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
            val view = LayoutInflater.from(parent.context)
                .inflate(R.layout.item2, parent, false)
            return ViewHolder(view).also {
                Log.d(TAG, "onCreateViewHolder $it")
            }
        }

        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
            holder.textView.text = dataSet[position]
            Log.d(TAG, "onBindViewHolder: " + holder)
        }

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

    companion object {
        val TAG = "Splash"
    }

}

下面是 splash.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:background="#ffffff">
	<androidx.viewpager2.widget.ViewPager2
		android:id="@+id/pager"
		android:background="#3F51B5"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent" />
</RelativeLayout>

最后是 item2.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffff00">
    <TextView
        android:id="@+id/textView"
        android:layout_centerInParent="true"
        android:layout_centerHorizontal="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="50dp"
        android:text="TextView" />
</RelativeLayout>

使用版本：

  implementation "androidx.viewpager2:viewpager2:1.0.0"