recyclerview实践demo，支持item点击事件

背景

项目中之前使用recyclerview较多，简单总结一下，持续优化。

基本使用

话不多说，直接上代码。

1、xml布局文件中个使用recyclerview。

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout 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=".activity.RecyclerViewActivity"> <androidx.recyclerview.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="match_parent" android:layout_height="match_parent"/> </androidx.constraintlayout.widget.ConstraintLayout>

2、activity中使用代码

public class RecyclerViewActivity extends AppCompatActivity { RecyclerView recyclerView; List<Sample> sampleList = new ArrayList<>(); int listSize = 100; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_recycler_view); recyclerView = findViewById(R.id.recyclerView); initSampleList(); ListAdapter listAdapter = new ListAdapter(sampleList, this); // 垂直线性布局 // LinearLayoutManager layoutManager = new LinearLayoutManager(null); // 瀑布流布局 StaggeredGridLayoutManager staggeredGridManager = new StaggeredGridLayoutManager(2, 1); // 1、设置adapter recyclerView.setAdapter(listAdapter); // 2、设置布局 recyclerView.setLayoutManager(staggeredGridManager); } private void initSampleList() { for (int i = 0; i < listSize; i++) { Sample sample = new Sample(); sample.setIcon(R.drawable.ball); sample.setTvName("ball: " + i); sample.setTvContent("ball price: " + i * 100); sampleList.add(sample); Sample sample1 = new Sample(); sample1.setIcon(R.drawable.tao); sample1.setTvName("tao: " + i); sample1.setTvContent("tao price: " + i * 100); sampleList.add(sample1); Sample sample2 = new Sample(); sample2.setIcon(R.drawable.apple); sample2.setTvName("apple: " + i); sample2.setTvContent("apple price: " + i * 100); sampleList.add(sample2); } } }

可以看到，recyclerview使用的关键是设置好对应的adapter。

3、自定义adapter，item监听可以放在ViewHolder中实现

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ListHolder> { List<Sample> sampleList; Context context; /** * 1、定义Adapter首先需要一个ViewHolder * 2、实现item监听可以放在ViewHolder中实现 */ static class ListHolder extends RecyclerView.ViewHolder implements View.OnClickListener { TextView tvName; TextView tvContent; ImageView ivIcon; Context context; public ListHolder(@NonNull View itemView, Context context) { super(itemView); tvName = itemView.findViewById(R.id.list_name); tvContent = itemView.findViewById(R.id.list_content); ivIcon = itemView.findViewById(R.id.list_icon); itemView.setOnClickListener(this); this.context = context; } @Override public void onClick(View v) { Toast.makeText(context, getAdapterPosition() + "", Toast.LENGTH_SHORT).show(); } /** * 给每个控件设置对应的数据 */ public void setData(Sample sample) { tvContent.setText(sample.getTvContent()); tvName.setText(sample.getTvName()); ivIcon.setImageResource(sample.getIcon()); } } /** * 构造函数 */ public ListAdapter(List<Sample> sampleList, Context context) { this.sampleList = sampleList; this.context = context; } /** * ViewHolder 首先用inflate方法解析布局，把整个布局传入，再通过ViewHolder把这个布局里的每个控件设置进来 */ @NonNull @Override public ListHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { View sampler = View.inflate(parent.getContext(), R.layout.layout_list,null); return new ListHolder(sampler, context); } @Override public void onBindViewHolder(@NonNull ListHolder holder, int position) { holder.setData(sampleList.get(position)); } @Override public int getItemCount() { if (sampleList != null) { return sampleList.size(); } return 0; } }

adapter中实现item的点击事件，是通过自定义ViewHolder实现的监听事件接口，对比看的话这是一种比较优雅的实现方案。 实现效果如下：