Question

这就是我制作出来的。

这第一件事是数据库，我不知道到底发生了什么，但它对我不起作用，它不会在应用程序中显示任何数据。

这是包含所有内容的代码

package com.ta3am.ta3ami.ta3ami;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.Picasso;
import com.ta3am.ta3ami.ta3ami.Common.Common;
import com.ta3am.ta3ami.ta3ami.Interface.ItemClickListener;
import com.ta3am.ta3ami.ta3ami.Model.Category;
import com.ta3am.ta3ami.ta3ami.ViewHolder.MenuViewHolder;

public class Home extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
    DatabaseReference ref;
    TextView txtFullName;
    RecyclerView recycler_menu;
    RecyclerView.LayoutManager layoutManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Menu");
        setSupportActionBar(toolbar);

        //Init Firebase
        ref = FirebaseDatabase.getInstance().getReference("Category");

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();
            }
        });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        //Set Name for user
        View headerView = navigationView.getHeaderView(0);
        txtFullName = (TextView)headerView.findViewById(R.id.txtFullName);
        txtFullName.setText(Common.currentUser.getName());

        //Load menu
        recycler_menu =(RecyclerView)findViewById(R.id.recycler_menu);
        recycler_menu.setHasFixedSize(true);
        layoutManager = new LinearLayoutManager(this);
        recycler_menu.setLayoutManager(layoutManager);
        loadMenu();
    }

    private void loadMenu() {

       FirebaseRecyclerAdapter<Category,MenuViewHolder> adapter=new FirebaseRecyclerAdapter <Category, MenuViewHolder>(Category.class, R.layout.menu_item, MenuViewHolder.class, ref) {

           @Override
           protected void populateViewHolder(MenuViewHolder viewHolder, Category model, int position) {

                viewHolder.txtMenuName.setText(model.getName());
                Picasso.with(getBaseContext()).load(model.getImage()).into(viewHolder.imageView);
                final Category clickItem =model;
                viewHolder.setItemClickListener(new ItemClickListener() {
                    @Override
                    public void onClick(View view, int position, boolean isLongClick) {
                        Toast.makeText(Home.this, ""+clickItem.getName(), Toast.LENGTH_SHORT).show();
                    }
                });
           }
        };
        recycler_menu.setAdapter(adapter);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.home, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_menu) {
            // Handle the camera action
        } else if (id == R.id.nav_cart) {

        } else if (id == R.id.nav_orders) {

        } else if (id == R.id.nav_log_out) {

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

关于其他代码的另一件事是ViewHolder，依此类推

package com.ta3am.ta3ami.ta3ami.ViewHolder;

import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import com.ta3am.ta3ami.ta3ami.Interface.ItemClickListener;
import com.ta3am.ta3ami.ta3ami.R;

public class MenuViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    public TextView txtMenuName;
    public ImageView imageView;

    private ItemClickListener itemClickListener;

    public MenuViewHolder(View itemView) {
        super(itemView);

        txtMenuName =(TextView)itemView.findViewById(R.id.menu_name);
        imageView =(ImageView)itemView.findViewById(R.id.menu_image);

        itemView.setOnClickListener(this);
    }

    public void setItemClickListener(ItemClickListener itemClickListener) {
        this.itemClickListener = itemClickListener;
    }

    @Override
    public void onClick(View view){
        itemClickListener.onClick(view,getAdapterPosition(),false);
    }
}

正如我所说的，这里的每件事对我来说都是一件好事，并且有害地工作，但我不知道数据有什么问题

package com.ta3am.ta3ami.ta3ami.Model;

import android.net.Uri;
import android.widget.ImageView;

public class Category {
    private String Name;
    private String Image;

    public Category() {
    }

    public Category(String name, String image) {
        Name = name;
        Image = image;
    }

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    public String getImage() {
        return Image;
    }

    public void setImage(String image) {
        Image = image;
    }
}

Answer 1

您尚未将布局管理器设置为适配器。请根据您的要求设置Layout Manager。像adapter.setLayoutManager(new LinearLayoutManager(context));，然后它将正常工作。

Answer 2

您必须更新FirebaseRecyclerAdapter的语法更新loadMenu（）方法。

private void loadMenu() {
            Query query = ref.limitToLast(10); // you can set data limit for how much data you want in list
            FirebaseRecyclerOptions dataoptions = new FirebaseRecyclerOptions.Builder<Category>().setQuery(query, Category.class).build();
            adapter=new FirebaseRecyclerAdapter <Category, MenuViewHolder>(dataoptions) {

                @Override
                protected void onBindViewHolder(MenuViewHolder viewHolder, Category model, int position) {
                    viewHolder.txtMenuName.setText(model.getName());
                    Picasso.with(getBaseContext()).load(model.getImage()).into(viewHolder.imageView);
                    final Category clickItem =model;
                    viewHolder.setItemClickListener(new ItemClickListener() {
                        @Override
                        public void onClick(View view, int position, boolean isLongClick) {
                            Toast.makeText(Home.this, ""+clickItem.getName(), Toast.LENGTH_SHORT).show();
                        }
                    });
                }
                @Override
                public MenuViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

                    View view = LayoutInflater.from(parent.getContext())
                            .inflate(R.layout.menu_item, parent, false);

                    return new MenuViewHolder(view);
                }

            };
            recycler_menu.setAdapter(adapter);
        }

之后，您需要在活动的OnStart（）方法中注册适配器侦听器。

    @Override
    protected void onStart() {
        super.onStart();
        adapter.startListening();
    }

它不会在recyclerviewer中显示项目

2 个答案: