Question

我正在使用FirebaseRecyclerAdapter，我需要显示使用ID等于true的帖子，这里是我的firebase数据库：

＆＃13;

{
  "Following" : {
    "ORBBKfZAAUhqI1h7ojQDzYOjgkp1" : {
      "z2SNUlLd6mQM8nnlkU2VUws5Ggl2" : {
        "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2"
      }
    },
    "pypD1SYZkbcYesk09WuMUY1AkTf1" : {
      "ORBBKfZAAUhqI1h7ojQDzYOjgkp1" : {
        "UID" : "ORBBKfZAAUhqI1h7ojQDzYOjgkp1",
        "Username" : "Ali"
      },
      "z2SNUlLd6mQM8nnlkU2VUws5Ggl2" : {
        "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2",
        "Username" : "Ali"
      }
    },
    "z2SNUlLd6mQM8nnlkU2VUws5Ggl2" : {
      "ORBBKfZAAUhqI1h7ojQDzYOjgkp1" : true,
      "pypD1SYZkbcYesk09WuMUY1AkTf1" : true
    }
  },
  "Posts" : {
    "-KduqnVVczZf5uibQiZ-" : {
      "Describe" : "gg",
      "Profile" : "https://twitter.com/2Top/profile_image?size=original",
      "Time" : 14881230655,
      "UID" : "pypD1SYZkbcYesk09WuMUY1AkTf1",
      "Username" : "Mike",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped906285501.jpg?alt=media&token=0c1a3a3d-6e48-4c4e-ba59-f5646bf8965f"
    },
    "-Ke5gJ00CxbjhOuhzLIx" : {
      "Describe" : "hajj",
      "Time" : 1488318465,
      "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2",
      "Username" : "Mike",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped1717103943.jpg?alt=media&token=a85b2488-5ac7-49a7-9ad0-dbf4e6f29389"
    },
    "-KeCuiFmUCpN19zwsTsR" : {
      "Describe" : "a",
      "Profile" : "https://lh4.googleusercontent.com/-suB77riNoX8/AAAAAAAAAAI/AAAAAAAAAAA/ADPlhfKMzINn-Ki538Sqf6SRGaXC81-WuQ/s200-c/photo.jpg",
      "Time" : 1488439652,
      "UID" : "ORBBKfZAAUhqI1h7ojQDzYOjgkp1",
      "Username" : "2top",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped1913886685.jpg?alt=media&token=c8ad26b2-8f09-453b-b48a-aad9e4d8b5c3"
    },
    "-KeD2fBUQ09HVMrvAneb" : {
      "Describe" : "ee",
      "Profile" : "https://lh4.googleusercontent.com/-suB77riNoX8/AAAAAAAAAAI/AAAAAAAAAAA/ADPlhfKMzINn-Ki538Sqf6SRGaXC81-WuQ/s200-c/photo.jpg",
      "Time" : 1488441999,
      "UID" : "ORBBKfZAAUhqI1h7ojQDzYOjgkp1",
      "Username" : "2to7p",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped1904338270.jpg?alt=media&token=d200b7fc-15e7-4dc4-9913-59c377929e9e"
    },
    "-KeDfnMWiB7k_4J3FBgZ" : {
      "Describe" : "f12g",
      "Profile" : "https://lh4.googleusercontent.com/-suB77riNoX8/AAAAAAAAAAI/AAAAAAAAAAA/ADPlhfKMzINn-Ki538Sqf6SRGaXC81-WuQ/s200-c/photo.jpg",
      "Time" : 1488452517,
      "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2",
      "Username" : "2top",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped1872832638.jpg?alt=media&token=80239844-a872-47e2-9689-92d368dd9452"
    },
    "-KeDfrw4inUQFtIDXJHp" : {
      "Describe" : "fg",
      "Profile" : "https://lh4.googleusercontent.com/-suB77riNoX8/AAAAAAAAAAI/AAAAAAAAAAA/ADPlhfKMzINn-Ki538Sqf6SRGaXC81-WuQ/s200-c/photo.jpg",
      "Time" : 1488452536,
      "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2",
      "Username" : "2top",
      "Wallpaper" : "https://firebasestorage.googleapis.com/v0/b/test-3f4c5.appspot.com/o/Posts%2Fcropped1872832638.jpg?alt=media&token=80239844-a872-47e2-9689-92d368dd9452"
    }
  },
  "Users" : {
    "1DUK1pHEEoaImX8iOOspEMEWCPm2" : {
      "Username" : "Tom"
    },
    "BQOwNdGAeRXiBnVj7ijY1EkFiDC3" : {
      "Username" : "7uthaifah"
    },
    "ECWHIksxJ0Q5SUlIrev4BjnjmrJ3" : {
      "Profile" : "https://lh3.googleusercontent.com/-p1mB5WbUN2s/AAAAAAAAAAI/AAAAAAAAAAo/r3Z4o-VSODQ/s200-c/photo.jpg",
      "Username" : "Jice"
    },
    "I5o3JMpYHwZXQD0t2ogWHCQbrZv1" : {
      "Profile" : "https://lh3.googleusercontent.com/-p1mB5WbUN2s/AAAAAAAAAAI/AAAAAAAAAAo/r3Z4o-VSODQ/s200-c/photo.jpg",
      "Username" : "Mike"
    },
    "ORBBKfZAAUhqI1h7ojQDzYOjgkp1" : {
      "Cover" : "http://lucascontabil.com/home/wp-content/uploads/2015/05/city-wallpaper-7-400x200.jpg",
      "Profile" : "https://lh5.googleusercontent.com/--IAMp28UlmE/AAAAAAAAAAI/AAAAAAAAAAA/AAomvV2EM8Ut2nW9j0YE2vRZhJyQBHMsrA/s200-c/photo.jpg",
      "UID" : "ORBBKfZAAUhqI1h7ojQDzYOjgkp1",
      "Username" : "Dom"
    },
    "ZxqBgLq4ekUJii05AvV86z0i3mH2" : {
      "Profile" : "https://lh3.googleusercontent.com/-p1mB5WbUN2s/AAAAAAAAAAI/AAAAAAAAAAo/r3Z4o-VSODQ/s200-c/photo.jpg",
      "Username" : "Jone"
    },
    "mZ5jjPNLlcc8OguVzWJLAYhavmg1" : {
      "Profile" : "https://twitter.com/2Top/profile_image?size=original",
      "Username" : "Twitter"
    },
    "pypD1SYZkbcYesk09WuMUY1AkTf1" : {
      "Profile" : "https://lh3.googleusercontent.com/-p1mB5WbUN2s/AAAAAAAAAAI/AAAAAAAAAAo/r3Z4o-VSODQ/s200-c/photo.jpg",
      "Username" : "Mike"
    },
    "z2SNUlLd6mQM8nnlkU2VUws5Ggl2" : {
      "Cover" : "http://lucascontabil.com/home/wp-content/uploads/2015/05/city-wallpaper-7-400x200.jpg",
      "Email" : "@dd",
      "Profile" : "https://lh4.googleusercontent.com/-suB77riNoX8/AAAAAAAAAAI/AAAAAAAAAAA/ADPlhfKMzINn-Ki538Sqf6SRGaXC81-WuQ/s200-c/photo.jpg",
      "UID" : "z2SNUlLd6mQM8nnlkU2VUws5Ggl2",
      "Username" : "2277top"
    }
  }
}

＆＃13;

我使用过这种方法，但它不起作用：

mDatabase = FirebaseDatabase.getInstance().getReference().child("Posts");

    mAuth = FirebaseAuth.getInstance();
    mCurrentUser = mAuth.getCurrentUser();

    mDatabaseFriends = FirebaseDatabase.getInstance().getReference().child("Following").child(mCurrentUser.getUid());

    Query q = mDatabaseFriends.orderByKey().equalTo(true);
    mQuery = mDatabase.orderByChild("UID").equalTo(q.toString());

    @Override
    public void onStart() {
        super.onStart();

        FirebaseRecyclerAdapter<Getting_Posts, PostViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Getting_Posts, PostViewHolder>(
                Getting_Posts.class, R.layout.post_card_design, PostViewHolder.class, mQuery) {
            @Override
            protected void populateViewHolder(final PostViewHolder viewHolder, final Getting_Posts model, int position) {}};

如果ids = true

，我需要使用它来显示帖子的查询

这是我使用它的方法，但它只显示以下第一个用户：

mDatabaseFriends.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for(DataSnapshot following : dataSnapshot.getChildren()) {

                Query X = mDatabase.orderByChild("UID").equalTo(following.getKey());

                FirebaseRecyclerAdapter<Getting_Posts, PostViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Getting_Posts, PostViewHolder>(
                        Getting_Posts.class, R.layout.post_card_design, PostViewHolder.class, X ) {}});

Answer 1

您可以使用常规的RecyclerAdapter实现您想要的效果。使用您当前的数据库设计，您将无法将所需内容转换为单个firebase查询，因此FirebaseRecyclerAdapter已经用完。

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

另一个选择是简单地更改数据库设计以允许使用FirebaseRecyclerAdapter或FirebaseIndexRecyclerAdapter（更有可能）。我认为你需要使用客户端扇出来实现这一点。

这些链接应该与您要实现的目标相关。

The Firebase Blog: Client-side fan-out

Firefeed

编辑：添加了特定于此情况的代码

已经有一段时间了，我现在无法测试代码，但请告诉我这是否适合您。

首先是适配器

mDatabaseFriends.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for(DataSnapshot following : dataSnapshot.getChildren()) {
                mDatabase.orderByChild("UID").equalTo(following.getKey()).addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        Getting_Posts model = dataSnapshot.getValue(Getting_Posts.class);
                        // Here you can add your 'post' to a dataset that you can use to initialize a new RecyclerAdapter
                    }

                    @Override
                    public void onCancelled(DatabaseError databaseError) {

                    }
                });
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

以下列方式使用它。在您的activity / fragment中声明以下属性。

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.PostViewHolder> {
    private ArrayList<Getting_Posts> mdataSet;

    public RecyclerAdapter(ArrayList<Getting_Posts> dataSet) {
        mdataSet = dataSet;
    }

    @Override
    public RecyclerAdapter.PostViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View inflatedView = LayoutInflater.from(parent.getContext()).inflate(R.layout.post_card_design, parent, false);
        return new PostViewHolder(inflatedView);
    }

    @Override
    public void onBindViewHolder(RecyclerAdapter.PostViewHolder holder, int position) {
        Gettings_Posts post = mdataSet.get(position);
        // Set the properties of the holder
        // I don't know what properties you used in the viewholder so I'll just give an example
        // example: holder.Name.setText(post.getName());
    }

    @Override
    public int getItemCount() {
        return mdataSet.size();
    }

    public void add(int position, Getting_Posts post) {
        mdataset.add(position, post);
        notifyItemInserted(position);
    }
}

在onCreate中将它们初始化为这样。

ArrayList<Getting_Posts> posts;
private RecyclerAdapter mAdapter;
private RecyclerView mRecycler;

然后添加原始解决方案，只需替换以下行

mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view); // Replace this with the ID of your recyclerView
mRecyclerView.setHasFixedSize(true);
LinearLayoutManager mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new RecyclerAdapter(posts);
mRecycler.setAdapter(mAdapter);

用这个

Getting_Posts model = dataSnapshot.getValue(Getting_Posts.class);

就像我说的那样，我没有时间测试它，所以可能会有一些错误，但我想给你一些工作。您应该能够在线找到大量有关RecyclerView和RecyclerAdapter的文档，以帮助您解决此问题。

如果值等于true，则Firebase会显示帖子

1 个答案:

编辑：添加了特定于此情况的代码