android - 更改适配器数据时 RecyclerView 滚动到顶部位置

Question

我对 RecyclerView 中的一篇文章喜欢和不喜欢，我在更改 View 后调用了 api，但问题是 RecyclerView 总是滚动到当我用更新通知它时，顶部。

这是我的适配器代码:

 likeAnim.setOnLikeListener(object : OnLikeListener {
            override fun liked(p0: LikeButton?) {
                if (commentList[position]!!.liked) {
                    // 
 likeButton.setBackgroundResource(R.drawable.heart_ico)
                    isLiked = false
                    callback(commentList[position], 2, layoutPosition)
                } else {
                    // likeButton.setBackgroundResource(R.drawable.filled_like_ico)
                    isLiked = true
                    callback(commentList[position], 1, layoutPosition)
                }
            }

            override fun unLiked(p0: LikeButton?) {
                if (commentList[position]!!.liked) {
                    // likeButton.setBackgroundResource(R.drawable.heart_ico)
                    isLiked = false
                    callback(commentList[position], 2, layoutPosition)
                } else {
                    // likeButton.setBackgroundResource(R.drawable.filled_like_ico)
                    isLiked = true
                    callback(commentList[position], 1, layoutPosition)
                }
            }
        })

这是我的 Activity 代码

        private fun onCommentActionSuccess(list: LikeRequestModel, type: Int, position: Int) {
    when (type) {
        1 -> Log.d("Success", "success: comment like done")
        2 -> Log.d("Success", "success: comment dislike done")
    }
    viewModel.getClassComments(LoginClass.login.user!!.data!!.school_classes_id!![0].id).observe(this@ClassHomeScreenActivity, Observer {
        when {
            it!!.isSuccess() -> onSuccessRefrech(it.data!!.data, position)
        }
    })
}

   private fun onSuccessRefrech(list: MutableList<ClasseCommentModel.Data?>, 
    position: Int) {
    Log.d("Success", "success: comment loaded")
    //initCommentAdapter(list)
    adapter.commentList = list
    // val adapter = ClassCommentsListAdapter(this@ClassHomeScreenActivity, 
      list) { it, type, pos ->
     // likeComment(it!!.id.toString(), type, pos)//Kotlin callback 
     instead of interface in java
    //  }
   // binding.postRV.swapAdapter(adapter, false)
    // adapter.notifyItemChanged(position)
    binding.postRV.scrollToPosition(position)
}

我的初始化适配器函数:

       private fun initCommentAdapter(list: 
        MutableList<ClasseCommentModel.Data?>) {
    adapter = ClassCommentsListAdapter(this@ClassHomeScreenActivity, list) { 
      it, type, position ->
        likeComment(it!!.id.toString(), type, position)//Kotlin callback 
      instead of interface in java
    }
    binding.postRV.setHasFixedSize(true) // 
    binding.postRV.itemAnimator = null // remove recycle view animation
    binding.postRV.layoutManager = 
     LinearLayoutManager(this@ClassHomeScreenActivity, 
      OrientationHelper.VERTICAL, false)
    binding.postRV.adapter = adapter
      }

我的回调函数:

       private fun likeComment(commentId: String, type: Int, position: Int) {
    when (type) {
        1 -> {
            viewModel.likeComment(commentId).observe(this@ClassHomeScreenActivity, Observer {
                when {
                    it!!.isError() -> onErrorAction(it.error)
                    it.isSuccess() -> onCommentActionSuccess(it.data!!, type, position)
                }
            })
        }
        2 -> {
            viewModel.dislikeComment(commentId).observe(this@ClassHomeScreenActivity, Observer {
                when {
                    it!!.isError() -> onErrorAction(it.error)
                    it.isSuccess() -> onCommentActionSuccess(it.data!!, type, position)
                }
            })
        }
    }
}

private fun onCommentActionSuccess(list: LikeRequestModel, type: Int, 
position: Int) {
    when (type) {
        1 -> Log.d("Success", "success: comment like done")
        2 -> Log.d("Success", "success: comment dislike done")
    }



 viewModel.getClassCommentsSingleEvent
 (LoginClass.login.user!!.data!!.school_clas 
  ses_id!![0].id).observe(this@ClassHomeScreenActivity, Observer {
        when {
            it!!.isSuccess() -> onSuccessRefrech(it.data!!.data, position)
        }
    })
}   

我想留在滚动位置而不滚动到顶部

Answer 1

一些提示:

1. 不要使用多个适配器对象。仅使用单个对象并尝试更新数据。更新数据后不要再设置adapter。

2. 更新列表后，只需调用 adapter.notifydatasetchanged() 即可解决您的问题。

希望这能解决您的问题。