RecyclerView系列：RecyclerView基本使用java版

Posted 2022-06-23 zhangjin1120

RecyclerView系列一直缺一篇基础使用的文章，终于补上了，为后续分析第三方库BaseRecyclerViewAdapterHelper做准备。

先上效果图，为了醒目，我加了边框背景。

我用的是android studio BumbleBee | 2021.1.1 Patch 3 ，新建项目后，默认导入了recyclerview，所以不用手动导入recyclerView的依赖。如下图：

低版本Android Studio还是需要手动导入的，可以参考：RecyclerView使用指南（一）—— 基本使用

布局文件activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:background="#000000"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

item的布局文件navigation_item.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/nav_item_layout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent">

    <ImageView
        android:id="@+id/nav_item_icon"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:src="@mipmap/icon_tabbar_home_sel"
        app:layout_constraintBottom_toTopOf="@id/nav_item_text"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent" />

    <TextView
        android:id="@+id/nav_item_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="首页"
        android:textColor="#ffffff"
        android:textSize="24sp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/nav_item_icon" />

</androidx.constraintlayout.widget.ConstraintLayout>

ItemData，NavigationViewAdapter一起贴出来

public class ItemData 
    public String title;
    public int imgId;

    public ItemData(String title, int imgId) 
        this.title = title;
        this.imgId = imgId;
    



public class NavigationViewAdapter extends RecyclerView.Adapter<NavigationViewAdapter.NavigationViewHolder> 

    private ArrayList<ItemData> list;
    public NavigationViewAdapter(ArrayList<ItemData> list)
        this.list = list;

    

    @NonNull
    @Override
    public NavigationViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.navigation_item, parent, false);
        NavigationViewHolder viewHolder = new NavigationViewHolder(view);
        return viewHolder;
    

    @Override
    public void onBindViewHolder(@NonNull NavigationViewHolder holder, int position) 
        ItemData itemData = list.get(position);
        holder.nagv_icon.setImageResource(itemData.imgId);
        holder.nagv_title.setText(itemData.title);
    

    @Override
    public int getItemCount() 
        return list.size();
    

    public static class NavigationViewHolder extends RecyclerView.ViewHolder 
        ImageView nagv_icon;
        TextView nagv_title;

        public NavigationViewHolder(@NonNull View itemView) 
            super(itemView);
            nagv_icon = itemView.findViewById(R.id.nav_item_icon);
            nagv_title = itemView.findViewById(R.id.nav_item_text);
        
    

MainActivity中初始化RecyclerView，设置LayoutMananger和Adapter

public class MainActivity extends AppCompatActivity 
    RecyclerView rv;
    ArrayList<ItemData> mList;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rv = findViewById(R.id.rv);
        initList();
        NavigationViewAdapter adapter = new NavigationViewAdapter(mList);
        LinearLayoutManager layoutManager = new LinearLayoutManager(MainActivity.this);
        rv.setLayoutManager(layoutManager);
        rv.setAdapter(adapter);
    

    private void initList() 
        mList = new ArrayList<>();
        mList.add(new ItemData("首页", R.mipmap.icon_tabbar_home_sel));
        mList.add(new ItemData("房间", R.mipmap.icon_tabbar_room));
        mList.add(new ItemData("全屋", R.mipmap.icon_tabbar_home_sel));
        mList.add(new ItemData("应用", R.mipmap.icon_tabbar_home_sel));
        mList.add(new ItemData("通行", R.mipmap.icon_tabbar_home_sel));
        mList.add(new ItemData("社区", R.mipmap.icon_tabbar_home_sel));
    

需要的两张图片

直接附在博客上有水印，所以大家自己去阿里巴巴矢量图标库上找吧！

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