Android多行横向来回自动滚动

使用自定义RecyclerView实现，先看效果，能用得上的再继续往下看……

上代码~

自定义AutoRollRecyclerView，继承RecyclerView，重点只有这一个类

class AutoRollRecyclerView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null
) : RecyclerView(context, attrs) {

    companion object {
        private const val TIME_AUTO_ROLL: Long = 16L //隔多长时间移动一次
    }

    private val autoPollTask by lazy { AutoRollTask() }
    private var running: Boolean = false //是否正在自动轮询
    private var canRun: Boolean = false//是否可以自动轮询

    inner class AutoRollTask : Runnable {

        private val distanceOnce = 1 //每次滚动距离设置
        private var isScrollToEnd = false //是否滚动到了最右边

        override fun run() {
            val recyclerView = this@AutoRollRecyclerView
            if (recyclerView.running && recyclerView.canRun) {

                //当前显示区域的宽度（屏幕从左到右可见区域） + 横向滚动偏移量 >= recyclerView的整体横向宽度（包含屏幕外的）
                if (recyclerView.computeHorizontalScrollExtent() + recyclerView.computeHorizontalScrollOffset() >= recyclerView.computeHorizontalScrollRange()) {
                    isScrollToEnd = true
                } else if (recyclerView.computeHorizontalScrollOffset() == 0) {
                    isScrollToEnd = false
                }
                //横向滚动，只修改x即可
                recyclerView.scrollBy(if (isScrollToEnd) -distanceOnce else distanceOnce, 0)
                //每隔TIME_AUTO_ROLL滚动一次
                recyclerView.postDelayed(recyclerView.autoPollTask, TIME_AUTO_ROLL)
            }
        }
    }

    /**
     * 开始
     */
    fun start() {
        if (running)
            stop()
        canRun = true
        running = true
        postDelayed(autoPollTask, TIME_AUTO_ROLL)
    }

    /**
     * 停止
     */
    fun stop() {
        running = false
        removeCallbacks(autoPollTask)
    }

    override fun onTouchEvent(e: MotionEvent): Boolean {
        when (e.action) {
            MotionEvent.ACTION_DOWN -> { //当点击按下时，停止滚动
                if (running)
                    stop()
            }
            MotionEvent.ACTION_UP,
            MotionEvent.ACTION_CANCEL,
            MotionEvent.ACTION_OUTSIDE -> { //松开时，继续滚动
                if (canRun)
                    start()
            }
        }
        return super.onTouchEvent(e)
    }
}

下面是Demo示例代码

布局文件：activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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:orientation="vertical"
    tools:context=".MainActivity">

    <!-- com.demo.application.widget 是AutoRollRecyclerView所在包-->
    <com.demo.application.widget.AutoRollRecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</androidx.appcompat.widget.LinearLayoutCompat>

每个item布局：item_topic.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.AppCompatTextView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/tvName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginHorizontal="5dp"
    android:layout_marginVertical="3dp"
    android:background="@drawable/shape_bg_topic"
    android:paddingHorizontal="10dp"
    android:paddingVertical="4dp"
    android:textColor="#00A89C"
    android:textSize="12sp"
    tools:text="# 书中自有浓情意浓情意" />

适配器TopicAdapter

/**
 * BaseQuickAdapter是第三方库BRVAH里的类（https://github.com/CymChad/BaseRecyclerViewAdapterHelper）
 * 可以在主module的build.gradle里引入
 * implementation 'io.github.cymchad:BaseRecyclerViewAdapterHelper:4.0.1'
 */
class TopicAdapter : BaseQuickAdapter<String, QuickViewHolder>() {

    override fun onBindViewHolder(holder: QuickViewHolder, position: Int, item: String?) {
        holder.setText(R.id.tvName, item)
    }

    override fun onCreateViewHolder(
        context: Context,
        parent: ViewGroup,
        viewType: Int
    ): QuickViewHolder {
        return QuickViewHolder(R.layout.item_topic, parent)
    }
}

MainActivity

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    private val adapter by lazy { TopicAdapter() }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        //横向Staggered布局
        binding.recyclerView.layoutManager =
            StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.HORIZONTAL)
        //设置adapter
        binding.recyclerView.adapter = adapter
        //填装数据
        adapter.submitList(
            arrayListOf(
                "# 书中自有颜如玉",
                "# 举头望明月",
                "# 贴贴",
                "# 哈哈哈哈哈哈",
                "# 极限运动",
                "# 请回答1988",
                "# 健身达人",
                "# LOL",
                "# 德玛西亚",
                "# 我的地盘听我的",
                "# 哼哼哈嘿"
            )
        )
    }

    override fun onResume() {
        super.onResume()
        binding.recyclerView.start()
    }

    override fun onPause() {
        super.onPause()
        binding.recyclerView.stop()
    }
}

▲新手小备注：Activity里使用了viewBinding，记得在模块build.gradle里开启支持

android {
    
    ……
    
    viewBinding {
        enabled = true
    }
}

结束~