Android RecyclerView paging/pager/page implements based on AsyncListUtil，kotlin

r囧r小猫 2023-10-10 22:26 29阅读 0赞

## Android RecyclerView paging/pager/page implements based on AsyncListUtil，kotlin ##

##  ##

import android.os.Bundle
    import android.util.Log
    import androidx.appcompat.app.AppCompatActivity
    import androidx.recyclerview.widget.GridLayoutManager
    import androidx.recyclerview.widget.RecyclerView
    import androidx.recyclerview.widget.RecyclerView.OnScrollListener
    import kotlinx.coroutines.CoroutineScope
    import kotlinx.coroutines.Dispatchers
    import kotlinx.coroutines.delay
    import kotlinx.coroutines.launch
    
    class MainActivity : AppCompatActivity() {
        companion object {
            val TAG = "test-log"
        }
    
        //假设已经知道全量数据，后续的分段是把源数据一片一片的截出来，装到新的分页数据集里面
        val ITEMS = ArrayList<MyData>()
        var COUNT = 0
    
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)
    
            var mRecyclerView: RecyclerView = findViewById<RecyclerView>(R.id.recycler_view)
            mRecyclerView?.layoutManager = GridLayoutManager(this, 3).apply {
                orientation = GridLayoutManager.VERTICAL
            }
    
            val mAdapter = MyAdapter()
            mRecyclerView?.adapter = mAdapter
    
            MyPagingRecyclerViewUtil.PAGE_SIZE = 50
            var mRecyclerViewUtil = MyPagingRecyclerViewUtil(mRecyclerView!!,
                object : MyPagingRecyclerViewUtil.PagingListener {
                    override fun onFillData(
                        data: Array<out Any>, startPosition: Int, itemCount: Int
                    ) {
                        Log.d(TAG, "onFillData $startPosition $itemCount")
                        fillData(startPosition, itemCount)
                    }
    
                    override fun onVisibleRange(fromPos: Int, toPos: Int) {
                        Log.d(TAG, "onVisibleRange $fromPos $toPos ${ITEMS.size}")
                    }
    
                    override fun refreshData(): Int {
                        return ITEMS.size
                    }
                })
    
            mRecyclerView?.addOnScrollListener(object : OnScrollListener() {
                override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                    mRecyclerViewUtil?.onRangeChanged()
                }
            })
    
            CoroutineScope(Dispatchers.IO).launch {
                repeat(Int.MAX_VALUE) {
                    ITEMS.clear()
    
                    COUNT = (200..400).random()
                    //COUNT=201
                    for (i in 0 until COUNT) {
                        var data = MyData("-$COUNT-")
                        ITEMS.add(data)
                    }
    
                    //触发onFillData()
                    mRecyclerViewUtil?.refresh()
                    delay(20) //如果不时延，新数据不能实时更新到UI
    
                    runOnUiThread {
                        mAdapter.onChange(ITEMS)
    
                        //RecyclerView启动后默认滚到最底部
                        //mRecyclerView?.scrollToPosition(mAdapter.getItemCount() - 1)
                    }
    
                    //模拟下一批新数据在此时间后到
                    delay(5000)
                }
            }
        }
    
        fun fillData(startPosition: Int, itemCount: Int) {
            var pos = 0
            for (i in 0 until itemCount) {
                pos = startPosition + i
                ITEMS.set(pos, MyData("$startPosition $i -$COUNT ${System.currentTimeMillis()}"))
            }
        }
    }

<?xml version="1.0" encoding="utf-8"?>
    <androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity" />

import android.util.Log
    import androidx.annotation.UiThread
    import androidx.annotation.WorkerThread
    import androidx.recyclerview.widget.AsyncListUtil
    import androidx.recyclerview.widget.GridLayoutManager
    import androidx.recyclerview.widget.RecyclerView
    
    
    class MyPagingRecyclerViewUtil(rv: RecyclerView, pagingListener: PagingListener) {
        companion object {
            var PAGE_SIZE = 200
        }
    
        private var mAsyncListUtil: AsyncListUtil<Any>? = null
    
        init {
            var viewCallback = PagingViewCallback(rv, pagingListener)
            var dataCallback = PageingDataCallback(pagingListener)
            mAsyncListUtil =
                AsyncListUtil(Any().javaClass, PAGE_SIZE, dataCallback, viewCallback)
        }
    
        fun onRangeChanged() {
            mAsyncListUtil?.onRangeChanged()
        }
    
        fun refresh(){
            Log.d(MainActivity.TAG,"refresh")
            mAsyncListUtil?.refresh()
        }
    
        private class PageingDataCallback(var listener: PagingListener) :
            AsyncListUtil.DataCallback<Any>() {
    
            //如果RecyclerView的数据源总长度发生变化，需要更新这个值，否则getItemRangeInto不会触发新的可视区域range更新。
            override fun refreshData(): Int {
                return listener?.refreshData() ?: 0
            }
    
            @WorkerThread
            override fun fillData(data: Array<out Any>, startPosition: Int, itemCount: Int) {
                listener?.onFillData(data, startPosition, itemCount)
            }
        }
    
        private class PagingViewCallback(val recyclerView: RecyclerView, var listener: PagingListener) :
            AsyncListUtil.ViewCallback() {
            fun getOutRange(rv: RecyclerView, outRange: IntArray) {
                outRange[0] = (rv.layoutManager as GridLayoutManager?)!!.findFirstVisibleItemPosition()
                outRange[1] = (rv.layoutManager as GridLayoutManager?)!!.findLastVisibleItemPosition()
            }
    
            override fun getItemRangeInto(outRange: IntArray) {
                getOutRange(recyclerView, outRange);
                listener?.onVisibleRange(outRange[0], outRange[1])
            }
    
            override fun onDataRefresh() {
    
            }
    
            override fun onItemLoaded(position: Int) {
    
            }
        }
    
    
        interface PagingListener {
            @WorkerThread
            fun onFillData(data: Array<out Any>, startPosition: Int, itemCount: Int) {
    
            }
    
            @UiThread
            fun onVisibleRange(fromPos: Int, toPos: Int) {
    
            }
    
            fun refreshData(): Int {
                return 0
            }
        }
    }

import android.view.LayoutInflater
    import android.view.View
    import android.view.ViewGroup
    import android.widget.TextView
    import androidx.annotation.MainThread
    import androidx.recyclerview.widget.RecyclerView
    
    class MyAdapter() : RecyclerView.Adapter<MyViewHolder>() {
        var items: ArrayList<MyData>? = ArrayList()
    
        @MainThread
        fun onChange(items: ArrayList<MyData>) {
            this.items = items
            this.notifyDataSetChanged()
        }
    
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
            val view = LayoutInflater.from(parent.context)
                .inflate(R.layout.item, parent, false)
            return MyViewHolder(view)
        }
    
        override fun getItemCount(): Int {
            return items?.size!!
        }
    
        override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
            holder.pos.text = "$position"
            holder.text.text = items?.get(position)?.str
        }
    }
    
    class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val pos: TextView = itemView.findViewById(R.id.pos)
        val text: TextView = itemView.findViewById(R.id.text)
    }
    
    data class MyData(var str: String)

<?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:orientation="vertical"
        android:paddingTop="5dp"
        android:paddingBottom="5dp">
    
        <TextView
            android:id="@+id/pos"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:textSize="30dp" />
    
        <TextView
            android:id="@+id/text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:textSize="12dp" />
    
    </LinearLayout>

![9576f75a2b9f44bc8855df9c107c5313.png][]

[Android RecyclerView page/paging load,kotlin（3）\_zhangphil的博客-CSDN博客基于Android官方Paging Library的RecyclerView分页加载框架我之前写了一篇RecyclerView分页加载机制的文章，是基于Android官方的AsyncListUtil实现的，详情见附录文章1。基于Android官方Paging Library的RecyclerView分页加载框架我之前写了一篇RecyclerView分页加载机制的文章，是基于Android官方的AsyncListUtil实现的，详情见附录文章1。【代码】Android Paging 3,kotlin（1）![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/130784241][Android RecyclerView page_paging load_kotlin_3_zhangphil_-CSDN_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android Paging 3_kotlin_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130784241]

[Android Paging3/Page3 Cursor query segment photo into 3 grid RecyclerView,kotlin （2）\_zhangphil的博客-CSDN博客基于Android官方Paging Library的RecyclerView分页加载框架我之前写了一篇RecyclerView分页加载机制的文章，是基于Android官方的AsyncListUtil实现的，详情见附录文章1。Android Paging Library是Android官方support。基于Android官方Paging Library的RecyclerView分页加载框架\_android setmainthreadexecutor\_zhangphil的博客-CSDN博客。![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/130751993][Android Paging3_Page3 Cursor query segment photo into 3 grid RecyclerView_kotlin _2_zhangphil_-CSDN_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android Paging Library_Android_support_Android_Paging Library_RecyclerView_android setmainthreadexecutor_zhangphil_-CSDN_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130751993]

[Android Paging 3 Flow or LiveData,kotlin（1）\_zhangphil的博客-CSDN博客【代码】Android Paging 3,kotlin（1）![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/130735753][Android Paging 3 Flow or LiveData_kotlin_1_zhangphil_-CSDN_Android Paging 3_kotlin_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130735753]

[Android Room联合AsyncListUtil实现RecyclerView分页加载ORM数据\_zhangphil的博客-CSDN博客Android Room联合AsyncListUtil实现RecyclerView分页加载ORM数据我之前写了一系列关于AsyncListUtil实现RecyclerView和ListView的分页加载机制和技术路线，见附录文章4,5。同时也写了一些列文章介绍Android官方推出的ORM数据库：Room技术，见附录文章1,2。现在结合Android分页加载框架AsyncListUtil，以及An![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/78661838][Android Room_AsyncListUtil_RecyclerView_ORM_zhangphil_-CSDN_Android Room_AsyncListUtil_RecyclerView_ORM_AsyncListUtil_RecyclerView_ListView_4_5_Android_ORM_Room_1_2_Android_AsyncListUtil_An_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_78661838]

[基于Android官方AsyncListUtil优化改进RecyclerView分页加载机制（一）\_recyclerview 分页机制\_zhangphil的博客-CSDN博客基于Android官方AsyncListUtil优化改进RecyclerView分页加载机制（一）Android AsyncListUtil是Android官方提供的专为列表这样的数据更新加载提供的异步加载组件。基于AsyncListUtil组件，可以轻易实现常见的RecyclerView分页加载技术。AsyncListUtil技术涉及的细节比较繁复，因此我将分别写若干篇文章，分点、分解Async![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/78603499][Android_AsyncListUtil_RecyclerView_recyclerview _zhangphil_-CSDN_Android_AsyncListUtil_RecyclerView_Android AsyncListUtil_Android_AsyncListUtil_RecyclerView_AsyncListUtil_Async_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_78603499]

[9576f75a2b9f44bc8855df9c107c5313.png]: https://img-blog.csdnimg.cn/9576f75a2b9f44bc8855df9c107c5313.png
[favicon32.ico]: https://g.csdnimg.cn/static/logo/favicon32.ico
[Android RecyclerView page_paging load_kotlin_3_zhangphil_-CSDN_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android Paging 3_kotlin_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130784241]: https://blog.csdn.net/zhangphil/article/details/130784241
[Android Paging3_Page3 Cursor query segment photo into 3 grid RecyclerView_kotlin _2_zhangphil_-CSDN_Android_Paging Library_RecyclerView_RecyclerView_Android_AsyncListUtil_1_Android Paging Library_Android_support_Android_Paging Library_RecyclerView_android setmainthreadexecutor_zhangphil_-CSDN_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130751993]: https://blog.csdn.net/zhangphil/article/details/130751993
[Android Paging 3 Flow or LiveData_kotlin_1_zhangphil_-CSDN_Android Paging 3_kotlin_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_130735753]: https://blog.csdn.net/zhangphil/article/details/130735753
[Android Room_AsyncListUtil_RecyclerView_ORM_zhangphil_-CSDN_Android Room_AsyncListUtil_RecyclerView_ORM_AsyncListUtil_RecyclerView_ListView_4_5_Android_ORM_Room_1_2_Android_AsyncListUtil_An_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_78661838]: https://blog.csdn.net/zhangphil/article/details/78661838
[Android_AsyncListUtil_RecyclerView_recyclerview _zhangphil_-CSDN_Android_AsyncListUtil_RecyclerView_Android AsyncListUtil_Android_AsyncListUtil_RecyclerView_AsyncListUtil_Async_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_78603499]: https://blog.csdn.net/zhangphil/article/details/78603499