android - 反转 GridRecyclerView Kotlin 中的空白

Question

所以这是我的 GridLayout 我已经声明了 LinearLayoutManager.VERTICAL, true

      var recyclerViewUploaded: RecyclerView? = null
        recyclerViewUploaded = my_posts_recycle
        recyclerViewUploaded.setHasFixedSize(true)
        val gridLayoutManager = GridLayoutManager(this, 2, LinearLayoutManager.VERTICAL, true )
        recyclerViewUploaded.layoutManager = gridLayoutManager
        postList = ArrayList()
        postAdapter = MypostsAdapter(this, postList as ArrayList<Post>)
        recyclerViewUploaded.adapter = postAdapter

应用截图

见上图，问题是它在顶部而不是底部留下了一个空白区域。

我曾尝试使用 Collections.reverse(postList) 但它给出了意想不到的结果，即 post order 123456 变为 125643 而不是 654321。

postList.reverse() 也不做任何事情！

这是我检索图像的功能。

  private fun retrievePosts() {
   val postsRef = FirebaseDatabase.getInstance().reference.child("Posts")
    postsRef.addValueEventListener(object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                (postList as ArrayList<Post>).clear()
                for (snapshot in dataSnapshot.children) {
                    val post = snapshot.getValue(Post::class.java)
                    if (post!!.getPublisher() == profileId) {
                        (postList as ArrayList<Post>).add(post)
                    }
                    if (postList.isNullOrEmpty()){
                        swipe_refresh_profile.isRefreshing = false
                    }
                    postList!!.reversed()
                    swipe_refresh_profile.isRefreshing = false
                    postAdapter!!.notifyDataSetChanged()
                }
            }
        }

        override fun onCancelled(error: DatabaseError) {
            TODO("Not yet implemented")
        }
    }
    )
}

这是我的 JSON 数据库结构

 "Posts" : {
"-MYkL70voeqXhrkli7vE" : {
  "caption" : "Setup by:- @iamlokesh_04\n\nSector Kwgt\nhttps://play.google.com/store/apps/details?id=sector.kustom.pack\n\nMini-music Kwgt\nhttps://play.google.com/store/apps/details?id=minimusicplayerforkwgt.kustom.pack\n\nSelf-made icons\nhttps://t.me/Iamlokesh_04\n\nHope you guys like it  ",
  "postid" : "-MYkL70voeqXhrkli7vE",
  "postimage" : "https://firebasestorage.googleapis.com/v0/b/android-customization.appspot.com/o/Posted%20Pictures%2FAkZI2A4EZbMOHCHPqZp4h4hl2zL2%2F1618940031310.jpg?alt=media&token=946e7836-b032-4d95-93ac-1c04d4342161",
  "publisher" : "AkZI2A4EZbMOHCHPqZp4h4hl2zL2"
},
"-MYkLhERZIZ5az-K3VrQ" : {
  "caption" : "Alpplications used: #37\n\n+Launcher - Nova launcher\n\n+Widgets - https://play.google.com/store/apps/details?id=flawlesskwgt.kustom.pack \n\n+Icon Pack - https://play.google.com/store/apps/details?id=com.panotogomo.darktosca\n\n+Wallpaper - https://play.google.com/store/apps/details?id=com.stark.fluid\n\nTemplate by - https://twitter.com/vhthinh_at?s=09 ",
  "postid" : "-MYkLhERZIZ5az-K3VrQ",
  "postimage" : "https://firebasestorage.googleapis.com/v0/b/android-customization.appspot.com/o/Posted%20Pictures%2FAkZI2A4EZbMOHCHPqZp4h4hl2zL2%2F1618940184176.jpg?alt=media&token=f6ced789-be42-4d72-873f-8316ce557ff9",
  "publisher" : "AkZI2A4EZbMOHCHPqZp4h4hl2zL2"
},
"-MYkLpNkeHPEWwmYDgwN" : {
  "caption" : "Rate my Setup!!  ",
  "postid" : "-MYkLpNkeHPEWwmYDgwN",
  "postimage" : "https://firebasestorage.googleapis.com/v0/b/android-customization.appspot.com/o/Posted%20Pictures%2FAkZI2A4EZbMOHCHPqZp4h4hl2zL2%2F1618940216883.jpg?alt=media&token=59c0b67e-bd5c-4b6c-9c14-36e16676bf58",
  "publisher" : "AkZI2A4EZbMOHCHPqZp4h4hl2zL2"
}

]

在这里，如果帖子的发布者 ID 与配置文件 ID 相同，则会将其添加到 postList 列表中。

我一直在寻找解决方案，任何帮助将不胜感激！

标签： androidfirebasekotlinfirebase-realtime-databasearraylist