如何从Firebase按时间顺序降序排序图像？

Question

我正在尝试在recyclerview中按时间顺序排列上传的照片，但出于某种原因，我的代码不起作用。

recyclerview适配器的代码：

 private void setupAdapter() {
    mPostAdapter = new FirebaseRecyclerAdapter<Post, PostHolder>(
            Post.class,
            R.layout.row_post,
            PostHolder.class,
            FirebaseUtils.getPostQuery()
    ) {

utils类的代码：

 public static DatabaseReference getPostRef() {
    return FirebaseDatabase.getInstance().getReference("posts");
}
public static Query getPostQuery() {
    return getPostRef().orderByChild("timeCreated");
}
public static DatabaseReference getMyPostRef() {
    return FirebaseDatabase.getInstance().getReference("my_posts")
            .child(getCurrentUser().getEmail().replace(".", ","));
}

这是数据库结构：

{
  ...
  "my_posts" : {
    "a@aa,com" : {
      "-KgHOJHOGHAPGyBuVbF5" : true
    },
    "afaf@sg,com" : {
      "-KgHXFz3NoshQNKbXz53" : true,
      "-KgHZJFpkQ7lxx7HcxEV" : true
    },
    ...
  },
  "posts" : {
    "-KgHOJHOGHAPGyBuVbF5" : {
      "numComments" : 0,
      "numLikes" : 0,
      "postId" : "-KgHOJHOGHAPGyBuVbF5",
      "postImageUrl" : "post_images/image:47620",
      "postText" : "",
      "timeCreated" : 1490662278306
    },
    ...
  },
  "posts_liked" : {
    "dskato0603@gmail,com" : {
      "-KgWIDHRyVoX4kHQlCvk" : true
    }
  },
  "user_record" : {
    "a@aa,com" : {
      "posts" : [ "-KgHOJHOGHAPGyBuVbF5" ]
    },
    "jxjsjskss@kfks,com" : {
      "comments" : [ "-KgLRZCT7A_OIZXwa5RD", "-KgLRaAybYi9p1AnO5tN", "-KgMUAKOc30PBRwm5icX" ],
      "posts" : [ "-KgHiMD5jlUcnHcLWcAi", "-KgL3MrPw2D6-N6VACKF", "-KgLDQxqaxVQNs9WcdEW" ]
    }
    ...
  }
}

Answer 1

尝试一下：

LinearLayoutManager linearlayoutmanager = new LinearLayoutManager(context this);
 linearlayoutmanager.setReverselayout(true);
 linearlayoutmanager.setStackFromEnd(true);
RecyclerView.setLayoutManager(linearlayoutmanager);