显示 recyclerview 不显示在片段中

Question

我在这个应用程序中使用了三个片段作为导航菜单。 我想将回收者视图放入故事片段中。 但我未能安装回收站视图。 我在下面分享代码。 您将给出其相关的解决方案。

首页 Activityclass.Java

package com.quotescollector;

导入androidx.annotation.NonNull；

导入 androidx.appcompat.app.ActionBarDrawerToggle；

导入androidx.appcompat.app.AppCompatActivity；

导入androidx.appcompat.widget.Toolbar；

导入androidx.core.view.GravityCompat；

导入androidx.drawerlayout.widget.DrawerLayout；

导入androidx.fragment.app.Fragment；

导入androidx.fragment.app.FragmentManager；

导入androidx.fragment.app.FragmentTransaction；

导入androidx.recyclerview.widget.RecyclerView；

导入 android.os.Bundle；

导入 android.view.MenuItem；

导入 com.google.android.material.navigation.NavigationView；

导入 com.quotescollector.Fragments.FragmentAbout；

导入 com.quotescollector.Fragments.FragmentStories；

导入 com.quotescollector.Fragments.FragmentSettings；

公共 class HomeActivity 扩展 AppCompatActivity {

DrawerLayout drawerLayout;

NavigationView navigationView;

Toolbar toolbar;

RecyclerView recyclerView;

@Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_home);

    // Now we will find the toolbar here//

    drawerLayout = findViewById(R.id.drawerLayout);

    navigationView = findViewById(R.id.navView);

    toolbar = findViewById(R.id.toolBar);

    recyclerView = findViewById(R.id.recyclerviewStories);

    //Now we will set the toolBar//

    setSupportActionBar(toolbar);

    getSupportActionBar().setTitle("Quotes Collectors");

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    //Now we set here the String arrays//

    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawerLayout,

工具栏，R.string.OpenDrawer，R.string.CloseDrawer）；

    drawerLayout.addDrawerListener(toggle);

    toggle.syncState();

    //Here we implement one method//

    navigationView.setNavigationItemSelectedListener(new 

NavigationView.OnNavigationItemSelectedListener() {

        @Override

        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            int id = item.getItemId();

            if (id == R.id.About) {

                loadFragment(new FragmentAbout());

            } else if (id == R.id.Stories) {
                loadFragment(new FragmentStories());
            } else {
                loadFragment(new FragmentSettings());
            }
            drawerLayout.closeDrawer(GravityCompat.START);
            return true;
        }
    });

}

@Override
public void onBackPressed() {
    if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
        drawerLayout.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
    super.onBackPressed();
}

private void loadFragment(Fragment fragment) {

    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.add(R.id.Content, fragment);
    fragmentTransaction.commit();
}

}

这是FragmentStoriesclass.java

package com.quotescollector.Fragments;

import android.os.Bundle;

import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.quotescollector.Models.StoriesModel;
import com.quotescollector.R;

import java.util.ArrayList;

public class FragmentStories extends Fragment {
    RecyclerView.Adapter adapter;
    RecyclerView recyclerView;
    ArrayList<StoriesModel> storiesModelList;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_stories, container, false);
        storiesModelList = new ArrayList<>();
        recyclerView = view.findViewById(R.id.recyclerviewStories);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        recyclerView.setAdapter(adapter);
        displayStories();
        return view;
    }
    private void displayStories() {
        storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
        storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));
        storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
        storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));
        storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
        storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));
    }
}

这是Stories Adapterclass.java

package com.quotescollector.Adapters;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.quotescollector.Models.StoriesModel;
import com.quotescollector.R;

import java.lang.reflect.Array;
import java.util.ArrayList;


public class StroiesAdapter extends RecyclerView.Adapter<StroiesAdapter.viewHolder> {

    ArrayList<StoriesModel> storiesModelArrayList;
    Context context;

    //Here we need a constructor//


    public StroiesAdapter(ArrayList<StoriesModel> storiesModelArrayList, Context context) {
        this.storiesModelArrayList = storiesModelArrayList;
        this.context = context;
    }

    @NonNull
    @Override
    public viewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.fragment_stories, parent, false);
        return new viewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull viewHolder holder, int position) {
        StoriesModel storiesModel = storiesModelArrayList.get(position);
        holder.image.setImageResource(storiesModel.getImage());
        holder.text.setText(storiesModel.getText());
    }

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

    public class viewHolder extends RecyclerView.ViewHolder {
        ImageView image;
        TextView text;

        public viewHolder(@NonNull View itemView) {
            super(itemView);

            image = itemView.findViewById(R.id.ImageFeather);
            text = itemView.findViewById(R.id.storiesHandler);
        }
    }
}

Stroies 片段XML 文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Fragments.FragmentStories">

    <!-- TODO: Update blank fragment layout -->

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerviewStories"
        android:layout_width="match_parent"
        tools:listitem="@layout/stories_fragment_sample_layout"
        android:layout_height="match_parent"/>

</LinearLayout>

它是带有 XML 文件和 java 类的故事片段数据。 我无法修复它。 指导我如何在导航菜单中显示 recyclerview。

Answer 1

您没有创建适配器 object 并且您创建了一个名为StroiesAdapter的适配器，但您使用的是错误的RecyclerView.Adapter ，这是更新的代码，试试这个：

 package com.quotescollector.Fragments;
    
    import android.os.Bundle;
    
    import androidx.fragment.app.Fragment;
    import androidx.recyclerview.widget.LinearLayoutManager;
    import androidx.recyclerview.widget.RecyclerView;
    
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    
    import com.quotescollector.Models.StoriesModel;
    import com.quotescollector.R;
    
    import java.util.ArrayList;
    
    public class FragmentStories extends Fragment {
        
        // here is the right type of adapter you made
        StroiesAdapter adapter; 

        RecyclerView recyclerView;
        ArrayList<StoriesModel> storiesModelList;
    
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            View view = inflater.inflate(R.layout.fragment_stories, container, false);
            storiesModelList = new ArrayList<>();
            recyclerView = view.findViewById(R.id.recyclerviewStories);
       
            displayStories();
            return view;
        }
        private void displayStories() {
            storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
            storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));
            storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
            storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));
            storiesModelList.add(new StoriesModel(R.drawable.stories, "Stories"));
            storiesModelList.add(new StoriesModel(R.drawable.asia, "asia"));

       // setting up your recyclerView and adapter after adding 
      // elements to the list.
      recyclerView.setLayoutManager(new 
                              LinearLayoutManager(getContext()));
           // making object for adpter
            adapter = new StroiesAdapter(storiesModelList, getContext());
           // now setting up the adpter
            recyclerView.setAdapter(adapter);

        }
    }