Android RecyclerView SearchView基本用法1

時間 2019-11-07

標籤 android recyclerview searchview 基本用法欄目 Android 简体版

原文原文鏈接

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

背景:

作了不少年的app開發，貌似沒見過沒有搜索功能的，搜索這個功能還真是挺常見的，通常包括本地搜索，好比筆記類的，有道雲筆記，或者Leanote，或者是qq，微信這樣的IM軟件，搜索本地聊天數據。也有一些是根據關鍵字，發起http請求，讓服務端搜索。在本文主要關注的是本地搜索，好比搜索數據庫中的內容，或者是其餘本地存儲的內容。android

一般會以爲寫搜索頁面，比較麻煩，至少我是這麼以爲的，關於RecyclerView跟SearchView準備多寫幾篇，這篇就講最基礎的使用方式，下篇會講在SearchView在Toolbar中的場景，也就是點擊搜索按鈕，進入搜索頁面自動展開搜索欄。數據庫

解決方案:

xml佈局文件微信

<?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設置的Adapter類app

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的佈局文件用的是Android系統提供的一個比較簡單的佈局，android.R.layout.simple_list_item_1。ide

對SearchView設置監聽事件佈局

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;
    }
});

因爲是本地搜索，但願的效果是能夠實時搜索，每輸入一個字符，就從新搜索一次，因而將搜索事件放到了onQueryTextChange()方法中，若是不但願實時搜索，能夠將過濾數據源的邏輯放到onQueryTextSubmit()方法中，當軟鍵盤彈起的時候，咱們會看到軟鍵盤上右下角是一個搜索的按鈕。點擊此按鈕就會觸發一次搜索。this

完整的java代碼以下：url

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);
        }
    }
}