1.首先，我们需要在build.gradle文件中引入paging3库：

dependencies { def paging_version = "3.0.0-alpha07" implementation "androidx.paging:paging-runtime:$paging_version" }

2.然后，在自定义AsyncPagingDataDiffer类中，我们可以使用DiffUtil进行数据差异比较并异步分发更新：

import androidx.paging.AsyncPagingDataDiffer import androidx.paging.AsyncPagingDataDiffer.PagingDataDiffData import androidx.recyclerview.widget.DiffUtil

class CustomAsyncPagingDataDiffer( private val callback: DiffUtil.ItemCallback ) : AsyncPagingDataDiffer(callback) {

override fun onCurrentListChanged(
    previousList: PagingData,
    currentList: PagingData,
    // after computing diff result on background thread, dispatch changes to the UI thread
    updateCallback: () -> Unit
) {
    computeDiffAsync(previousList, currentList) { diffResult ->
        updateCallback() // trigger update on UI thread
        dispatchDiff(diffResult, previousList, currentList)
    }
}

// asynchronous diff computation
private fun computeDiffAsync(
    previousList: PagingData,
    currentList: PagingData,
    callback: (DiffUtil.DiffResult) -> Unit
) {
    val callbackByField = callbackByField(previousList, currentList)
    val diffCallback = object : DiffUtil.Callback() {
        override fun getOldListSize() = previousList.size
        override fun getNewListSize() = currentList.size
        override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int) =
            callbackByField.areItemsTheSame(
                previousList[oldItemPosition],
                currentList[newItemPosition]
            )
        override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int) =
            callbackByField.areContentsTheSame(
                previousList[oldItemPosition],
                currentList[newItemPosition]
            )
        override fun getChangePayload(oldItemPosition: Int, newItemPosition: Int) =
            callbackByField.getChangePayload(
                previousList[oldItemPosition],
                currentList[newItemPosition]
            )
    }
    DiffUtil
        .calculateDiff(diffCallback, false)
        .dispatchUpdatesTo { diffResult, _ -> callback(diffResult) }
}

// diffUtil callback to pass in
private fun callbackByField(
    previousList: PagingData,
    currentList: PagingData
): DiffUtil.ItemCallback = object : DiffUtil.ItemCallback() {
    override fun areItemsTheSame(oldItem: