如何创建按类别显示数据的多回收视图

Question

在我的项目中，我想按类别查询显示从 firebase 到 recycleview 的信息，例如：

布局 1 包含菜单查询 A 布局 2 包含一个菜单查询 B 等等

这是我的代码

   @ Override
     protected void onCreate (Bundle savedInstanceState) {
         super.onCreate (savedInstanceState);
         setContentView (R.layout.activity_post_list);



     // ActionBar actionBar = getSupportActionBar ();
       // actionBar.setTitle ("post list");

         mRecyclerView = findViewById (R.id.recyclerView);
         mRecyclerView.setHasFixedSize (true);
         mRecyclerView.setLayoutManager (new LinearLayoutManager (this));
         mFirebaseDatabase = FirebaseDatabase.getInstance ();

         mRef = mFirebaseDatabase.getReference ("Data / Menu1"); //this section takes queries from firebase addresses


     }

this is my firebase query

如何在不制作很多的情况下制作多个回收视图类？

Answer 1

Android 开发教程 - Recycler View in Recycler View like Google Play using Firebase Realtime Database.

希望本视频对您有所帮助。 https://www.youtube.com/watch?v=K2FSLZzYnnQ&t=1s

Answer 2

要按类别显示数据，您可以使用分段适配器。请看一个例​​子 https://github.com/luizgrp/SectionedRecyclerViewAdapter

Answer 3

您可以试试这个 activity 作为入门示例

SampleActivity.java

public class SampleActivity extends AppCompatActivity {
    DatabaseReference mRef;
    FirebaseDatabase mFirebaseDatabase;
    RecyclerView mRecyclerView;


    ArrayList<InnerDataModel> innerDataModelsMenu1ForAdapter;
    ArrayList<InnerDataModel> innerDataModelsMenu2ForAdapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sample);
        mRecyclerView = findViewById(R.id.recyclerView);
        innerDataModelsMenu1ForAdapter = new ArrayList<>();
        innerDataModelsMenu2ForAdapter = new ArrayList<>();
    }


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

        getDataFromFirestore();
    }

    private void getDataFromFirestore() {

        mFirebaseDatabase = FirebaseDatabase.getInstance();
        mRef = mFirebaseDatabase.getReference("Data/");
        //Get all the data from the Firbase Realtime Database
        mRef.addListenerForSingleValueEvent(new ValueEventListener() {

            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

                for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                    String menuType = snapshot.getKey();
                    if (!TextUtils.isEmpty(menuType)) {
                        //Write logic for each different menu type

                        ArrayList<InnerDataModel> innerDataModelsMenu1 = new ArrayList<InnerDataModel>();
                        ArrayList<InnerDataModel> innerDataModelsMenu2 = new ArrayList<InnerDataModel>();

                        if (menuType.equals("Menu1")) {

                            for (DataSnapshot snapshotInner : dataSnapshot.child("Menu1").getChildren()) {
                                innerDataModelsMenu1.add(snapshotInner.getValue(InnerDataModel.class));
                            }

                            runCodeForMenu1(innerDataModelsMenu1);
                        }
                        if (menuType.equals("Menu2")) {

                            for (DataSnapshot snapshotInner : dataSnapshot.child("Menu2").getChildren()) {
                                innerDataModelsMenu2.add(snapshotInner.getValue(InnerDataModel.class));
                            }

                            runCodeForMenu2(innerDataModelsMenu2);
                        }
                    }
                }

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
                //No Data present
            }

        });


    }

    private void runCodeForMenu2(ArrayList<InnerDataModel> children) {

        innerDataModelsMenu2ForAdapter.addAll(children);
        Log.d("SampleActivity", innerDataModelsMenu2ForAdapter.toString() + "");

    }

    private void runCodeForMenu1(ArrayList<InnerDataModel> children) {
        innerDataModelsMenu1ForAdapter.addAll(children);
        Log.d("SampleActivity", innerDataModelsMenu1ForAdapter.toString() + "");
    }
}

InnerDataModel.java

public class InnerDataModel {
    private String image;
    private String title;
    private String description;

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

从 FireBase 接收并处理数据后，您可以根据两个全局 ArrayLists innerDataModelsMenu1ForAdapter 和 innerDataModelsMenu2ForAdapter 处理您的适配器，并在您的 activity 显示 CardView

中的数据