android - NotifyDataSetChanged 方法不会刷新我的 RecyclerView Kotlin

Question

我试图理解为什么适配器方法notifyDataSetChanged()不刷新我的回收 View 。我在适配器中创建方法时找到了一个解决方案，如下所示:

 fun setData(list: List<DownloadModel>){
    resumeList = list
    notifyDataSetChanged()
 }

这个解决方案有效，但是，我想知道为什么我不能做这样的事情:

private lateinit var downloadAdapter: DownloadRecyclerAdapter

private fun setupAdapter() {
    downloadAdapter = DownloadRecyclerAdapter(
        this@DownloadActivity,
        downloadList,
        { id -> onViewClick(id) },
        { id -> onEditClick(id) },
        { id, position -> onDeleteClick(id, position) }
    )

    savedResumeRv.apply {
        layoutManager = LinearLayoutManager(context)
        layoutAnimation = AnimationUtils.loadLayoutAnimation(
            this@DownloadActivity,
            R.anim.layout_animation_down_to_up
        )
        adapter = downloadAdapter

    }
}

private fun observers() {
    downloadViewModel.getDownloadList().observe(this, Observer { list ->
        downloadList = list
        list?.let {
            downloadAdapter.notifyDataSetChanged()
            }
        })
}

downloadAdapter 持有列表 downloadList 的相同实例，我想知道为什么当我通知 Activity 中的适配器时无法正常工作。

Answer 1

 downloadList = list

由于这一行，下载列表的引用不再相同

尝试

private fun observers() {
    downloadViewModel.getDownloadList().observe(this, Observer { list ->
      with(downloadList){
    clear()
    addAll(list)
}
        downloadList?.let {
            downloadAdapter.notifyDataSetChanged()
            }
        })
}