如何在Android上的RecyclerView上滚动时修复计时器？

Question

在我的应用程序中，我想使用多个CountDownTimer来显示RecyclerView中的优惠时间。我已经在Kotlin中编写了下面的代码，但在滚动时，计时器不断重启。例如，计时器从4:19开始，而滚动而不是在10秒后显示4:09仍显示4:19。

活动代码：

class MainActivity : AppCompatActivity() {

    private lateinit var apisList: ApisList
    private lateinit var retrofit: Retrofit
    private lateinit var todayAdapter: AuctionsTodayAdapter
    private val todayModel: MutableList<Today> = mutableListOf()
    private lateinit var layoutManager: RecyclerView.LayoutManager

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        //Initialize
        retrofit = ApiClient.instance
        apisList = retrofit.create(ApisList::class.java)
        todayAdapter = AuctionsTodayAdapter(themedContext, todayModel)
        layoutManager = LinearLayoutManager(themedContext)
        //RecyclerView
        main_list.setHasFixedSize(true)
        main_list.layoutManager = layoutManager
        main_list.adapter = todayAdapter

        if (isNetworkAvailable()) getData(1, 10)
    }

    private fun getData(page: Int, limit: Int) {
        main_loader.visibility = View.VISIBLE
        val call = apisList.getAuctionsToday(page, limit)
        call.let {
            it.enqueue(object : Callback<AuctionsTodayResponse> {
                override fun onFailure(call: Call<AuctionsTodayResponse>, t: Throwable) {
                    main_loader.visibility = View.GONE
                    Log.e("auctionsTodayList", t.message)
                }

                override fun onResponse(call: Call<AuctionsTodayResponse>, response: Response<AuctionsTodayResponse>) {
                    if (response.isSuccessful) {
                        response.body()?.let { itBody ->
                            main_loader.visibility = View.GONE
                            if (itBody.toString().isNotEmpty()) {
                                todayModel.clear()
                                todayModel.addAll(itBody.res.today)
                                todayAdapter.notifyDataSetChanged()
                            }
                        }
                    }
                }
            })
        }
    }
}

适配器代码：

class AuctionsTodayAdapter(val context: Context, val model: MutableList<Today>) :
    RecyclerView.Adapter<AuctionsTodayAdapter.MyHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyHolder {
        val view = LayoutInflater.from(context).inflate(R.layout.row_main_list, parent, false)
        val holder = MyHolder(view)

        //holder.setIsRecyclable(false)

        return holder
    }

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

    override fun onBindViewHolder(holder: MyHolder, position: Int) {
        val modelUse = model[position]
        holder.setData(modelUse)



        if (holder.newCountDownTimer != null) {
            holder.newCountDownTimer!!.cancel()
        }
        var timer = modelUse.calculateEnd

        timer = timer * 1000

        holder.newCountDownTimer = object : CountDownTimer(timer, 1000) {
            override fun onTick(millisUntilFinished: Long) {
                var seconds = (millisUntilFinished / 1000).toInt()
                val hours = seconds / (60 * 60)
                val tempMint = seconds - hours * 60 * 60
                val minutes = tempMint / 60
                seconds = tempMint - minutes * 60
                holder.rowMain_timer.rowMain_timer.text =
                    String.format("%02d", hours) + ":" + String.format(
                        "%02d",
                        minutes
                    ) + ":" + String.format("%02d", seconds)
            }

            override fun onFinish() {
                holder.rowMain_timer.text = "00:00:00"
            }
        }.start()

    }

    inner class MyHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        var newCountDownTimer: CountDownTimer? = null

        lateinit var rowMain_timer: TextView

        init {
            rowMain_timer = itemView.findViewById(R.id.rowMain_timer)
        }

        fun setData(model: Today) {
            model.image.let {
                Glide.with(context)
                    .load(Constants.MAIN_BASE_URL + it)
                    .apply(RequestOptions.diskCacheStrategyOf(DiskCacheStrategy.RESOURCE))
                    .into(itemView.rowMain_img)
            }
            model.title.let { itemView.rowMain_title.text = it }
        }
}

我怎样才能解决这个问题？

Answer 1

当你想在你的适配器中使用Timer时，不应该在onBindViewHolder中使用它。 因为onBindViewHolder会在您滚动项目时调用每个项目 您应该使用Timer进入适配器的构造函数，并且每隔一秒使用notifyDataSetChanged您的适配器。 别担心，这种结构并不坏结构而不是内存泄漏。你可以在个人资料标签中查看！

class AuctionsTodayAdapter(val context: Context, val model: MutableList<Today>) :
    RecyclerView.Adapter<AuctionsTodayAdapter.MyHolder>() {

    private var newData: Long = 0

    init {
        for (items in model) {
            items.end.let {
                newData = items.end.toLong()
            }
        }
        //set the timer which will refresh the data every 1 second.
        object : CountDownTimer(newData, 1000) {
            override fun onFinish() {
                notifyDataSetChanged()
            }

            override fun onTick(p0: Long) {
                var i = 0
                val dataLength = model.size
                while (i < dataLength) {
                    val item = model[i]
                    item.end -= 1000
                    i++
                }
                notifyDataSetChanged()
            }
        }.start()
    }

    override fun onBindViewHolder(holder: MyHolder, position: Int) {
        var modelUse = model[position]
        //Img
        modelUse.image.let {
            Glide.with(context)
                .load(Constants.MAIN_BASE_URL + it)
                .apply(RequestOptions.diskCacheStrategyOf(DiskCacheStrategy.RESOURCE))
                .into(holder.rowMAIN_img)
        }
        //Timer
        modelUse.end.let {
            if (modelUse.calculateEnd > 0) {
                holder.rowMAIN_timer.text = getDurationBreakdown(modelUse.end.toLong())
            } else {
                holder.rowMain_timer.text = "Finished"
            }
        }
    }

    private fun millToMins(milliSec: Long): String {
        var seconds = (milliSec / 1000).toInt()
        val hours = seconds / (60 * 60)
        val tempMint = seconds - hours * 60 * 60
        val minutes = tempMint / 60
        seconds = tempMint - minutes * 60

        return String.format("%02d", hours) + ":" + String.format(
            "%02d",
            minutes
        ) + ":" + String.format("%02d", seconds)
    }
}

我希望我能帮助你。

Answer 2

每个CountDownTimer都有ViewHolder。每次滚动，recyclerView都会创建新的CountDownTimer。所以，如果我正确地得到你的问题，你应该有整个适配器的单个CountDownTimer。使其成为适配器类的本地字段。