安卓中使用ViewPager2实现上下滑动翻页

目标

实现上下滑动翻页,类似于抖音、快手短视频的操作方式.

实现方案

• 添加依赖

implementation "androidx.viewpager2:viewpager2:1.0.0"
      

• 布局文件:activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<androidx.viewpager2.widget.ViewPager2
android:id="@+id/vp2"
android:layout_width="match_parent"
android:layout_height="match_parent" />

</LinearLayout>
      

• 适配器

class MyAdapter(fragmentActivity: FragmentActivity, private val fragments: ArrayList<Fragment>) :
    FragmentStateAdapter(fragmentActivity) {
    override fun createFragment(position: Int) = fragments[position]

    override fun getItemCount() = fragments.size
}
      

• Fragment

class Fragment1 : Fragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val tv = TextView(context)
        tv.text = "第一页"
        tv.setBackgroundColor(Color.parseColor("#f7acbc"))
        tv.gravity = Gravity.CENTER
        return tv
    }
}
class Fragment2 : Fragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val tv = TextView(context)
        tv.text = "第二页"
        tv.setBackgroundColor(Color.parseColor("#9b95c9"))
        tv.gravity = Gravity.CENTER
        return tv
    }
}
      

• 调用

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val vp2 = findViewById<View>(R.id.vp2) as ViewPager2
        val fragment1 = Fragment1()
        val fragment2 = Fragment2()
        val fragments = ArrayList<Fragment>()
        fragments.add(fragment1)
        fragments.add(fragment2)
        //设置上下滑动
        vp2.orientation = ViewPager2.ORIENTATION_VERTICAL
        vp2.adapter = MyAdapter(this, fragments)
    }
}