Android RecyclerView SearchView基本用法1

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本文同步自http://javaexception.com/archives/82

背景:

做了很多年的app开发,貌似没见过没有搜索功能的,搜索这个功能还真是挺常见的,一般包括本地搜索,比如笔记类的,有道云笔记,或者Leanote,或者是qq,微信这样的IM软件,搜索本地聊天数据。也有一些是根据关键字,发起http请求,让服务端搜索。在本文主要关注的是本地搜索,比如搜索数据库中的内容,或者是其他本地存储的内容。

通常会觉得写搜索页面,比较麻烦,至少我是这么觉得的,关于RecyclerView跟SearchView准备多写几篇,这篇就讲最基础的使用方式,下篇会讲在SearchView在Toolbar中的场景,也就是点击搜索按钮,进入搜索页面自动展开搜索栏。

解决方案:

xml布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">
 
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
 
        <android.support.v7.widget.SearchView
            android:id="@+id/search_view"
            android:layout_width="match_parent"
            app:queryHint="搜索"
            android:layout_height="wrap_content" />
 
        <View
            android:layout_width="match_parent"
            android:background="#dddddd"
            android:layout_height="1px"/>
    </LinearLayout>
 
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_marginTop="2dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
 
</LinearLayout>

RecyclerView设置的Adapter类

class Adapter extends RecyclerView.Adapter {
    private List<String> datas = new ArrayList<>();
 
    public void setDatas(List<String> datas) {
        this.datas = datas;
    }
 
    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(android.R.layout.simple_list_item_1, viewGroup, false);
        return new ViewHolder(view);
    }
 
    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
        ViewHolder holder = (ViewHolder) viewHolder;
        holder.textView.setText(datas.get(position));
    }
 
    @Override
    public int getItemCount() {
        return datas.size();
    }
}
 
class ViewHolder extends RecyclerView.ViewHolder {
    TextView textView;
 
    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        textView = itemView.findViewById(android.R.id.text1);
    }
}

RecyclerView item的布局文件用的是Android系统提供的一个比较简单的布局,android.R.layout.simple_list_item_1。

对SearchView设置监听事件

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }
 
    @Override
    public boolean onQueryTextChange(String newText) {
        if (TextUtils.isEmpty(newText)) {
            adapter.setDatas(datas);
            adapter.notifyDataSetChanged();
        } else {
            adapter.setDatas(search(newText));
            adapter.notifyDataSetChanged();
        }
        return false;
    }
});

由于是本地搜索,希望的效果是可以实时搜索,每输入一个字符,就重新搜索一次,于是将搜索事件放到了onQueryTextChange()方法中,如果不希望实时搜索,可以将过滤数据源的逻辑放到onQueryTextSubmit()方法中,当软键盘弹起的时候,我们会看到软键盘上右下角是一个搜索的按钮。点击此按钮就会触发一次搜索。

完整的java代码如下:

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
 
    private SearchView searchView;
    private RecyclerView recyclerView;
    private Adapter adapter;
    private List<String> datas;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        searchView = findViewById(R.id.search_view);
        recyclerView = findViewById(R.id.recycler_view);
        adapter = new Adapter();
        datas = generateDatas();
        adapter.setDatas(datas);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }
 
            @Override
            public boolean onQueryTextChange(String newText) {
                if (TextUtils.isEmpty(newText)) {
                    adapter.setDatas(datas);
                    adapter.notifyDataSetChanged();
                } else {
                    adapter.setDatas(search(newText));
                    adapter.notifyDataSetChanged();
                }
                return false;
            }
        });
    }
 
    private List<String> search(String query) {
        List<String> filterDatas = new ArrayList<>();
        for (String source : datas) {
            if (source.contains(query)) {
                filterDatas.add(source);
            }
        }
        return filterDatas;
    }
 
    private List<String> generateDatas() {
        List<String> list = new ArrayList<>();
        for (int index = 0; index < 10; index++) {
            list.add("Hello World " + (index + 1));
        }
        return list;
    }
 
    class Adapter extends RecyclerView.Adapter {
        private List<String> datas = new ArrayList<>();
 
        public void setDatas(List<String> datas) {
            this.datas = datas;
        }
 
        @NonNull
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
            View view = LayoutInflater.from(viewGroup.getContext()).inflate(android.R.layout.simple_list_item_1, viewGroup, false);
            return new ViewHolder(view);
        }
 
        @Override
        public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
            ViewHolder holder = (ViewHolder) viewHolder;
            holder.textView.setText(datas.get(position));
        }
 
        @Override
        public int getItemCount() {
            return datas.size();
        }
    }
 
    class ViewHolder extends RecyclerView.ViewHolder {
        TextView textView;
 
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            textView = itemView.findViewById(android.R.id.text1);
        }
    }
}

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Android RecyclerView SearchView基本用法1

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