Android 检测到协同路由、异步DiffUtil和不一致性错误

我在组合Kotlin流和异步DiffUtil时遇到问题

我的RecyclerView.Adapter中有此函数，它在计算线程上计算DiffUtil并在主线程上向RecyclerView发送更新：

suspend fun updateDataset(newDataset: List<Item>) = withContext(Dispatchers.Default) {
        val diff = DiffUtil.calculateDiff(object : DiffUtil.Callback()
        {
            override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean
                    = dataset[oldItemPosition].conversation.id == newDataset[newItemPosition].conversation.id

            override fun getOldListSize(): Int = dataset.size
            override fun getNewListSize(): Int = newDataset.size

            override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean
                    = dataset[oldItemPosition] == newDataset[newItemPosition]
        })

        withContext(Dispatchers.Main) {
            dataset = newDataset // <-- dataset is the Adapter's dataset
            diff.dispatchUpdatesTo(this@ConversationsAdapter)
        }
    }

---

由于主线程（而且只有它）执行这两个操作，我怎么可能得到这个错误？

您的差异正在加速。如果您的更新在短时间内出现两次，则可能发生以下情况：

Adapter has dataset 1 @Main
Dataset 2 comes
calculateDiff between 1 & 2 @Async
Dataset 3 comes
calculateDiff between 1 & 3 @Async
finished calculating diff between 1 & 2 @ Async
finished calculating diff between 1 & 3 @ Async
Dispatcher main starts handling messages
replace dataset 1 with dataset 2 using 1-2 diff @Main
replace dataset 2 with dataset 3 using 1-3 diff @Main - inconsistency

替代方案是1-3之间的差异可以在1-2之前完成，但问题保持不变。 当新的计算出现时，您必须取消正在进行的计算，并防止部署无效的差异，例如，在片段中存储作业引用：

var updateJob : Job? = null

private fun updateConversationsList(conversations: List<ConversationsAdapter.Item>)
{
    updateJob?.cancel()
    updateJob = viewLifecycleOwner.lifecycleScope.launch {
        (listConversations.adapter as ConversationsAdapter).updateDataset(conversations)
    }
}

var updateJob:Job？=无效的
私人娱乐更新会话列表（会话：列表）
{
updateJob？.cancel（）
updateJob=viewLifecycleOwner.lifecycleScope.launch{
（listConversations.adapter作为ConversationsAdapter）。updateDataset（conversations）
}
}

---

如果您取消它，那么

withContext（Dispatchers.Main）

将在内部检查继续状态，并且不会运行。

。1.您是否查看了

ListAdapter

和

DiffUtil.ItemCallback

？2.Square正在开发使用

DiffUtil

和协同程序来实现您想要的功能，它可能是一个很好的参考源。感谢cycler，我不知道它看起来很有趣清楚的解释和干净的解决方案。非常感谢。

Adapter has dataset 1 @Main
Dataset 2 comes
calculateDiff between 1 & 2 @Async
Dataset 3 comes
calculateDiff between 1 & 3 @Async
finished calculating diff between 1 & 2 @ Async
finished calculating diff between 1 & 3 @ Async
Dispatcher main starts handling messages
replace dataset 1 with dataset 2 using 1-2 diff @Main
replace dataset 2 with dataset 3 using 1-3 diff @Main - inconsistency

var updateJob : Job? = null

private fun updateConversationsList(conversations: List<ConversationsAdapter.Item>)
{
    updateJob?.cancel()
    updateJob = viewLifecycleOwner.lifecycleScope.launch {
        (listConversations.adapter as ConversationsAdapter).updateDataset(conversations)
    }
}