Java 当我尝试搜索HashMap时，没有发生任何事情

我正在尝试实现一个功能，允许我搜索我的所有歌曲，这些歌曲存储在名为songsList的HashMap中。我已经成功实现了SongslistHashMap。我尝试使用用户键入的字符串过滤结果，该字符串是在用户单击搜索图标时输入的，但什么也没有发生

你知道为什么SongslistHashMap没有被过滤吗

我尝试了区分大小写和不区分大小写的搜索。我试着在完整准确的歌名中搜索几首歌。所以我不认为我正在测试的搜索字符串是一个问题，而是我的代码中的一些东西

playlativity.java

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Locale;

public class PlayListActivity extends ListActivity {

    private EditText editSearch;
    private ImageView searchIcon;
    private ListAdapter adapter;
    private ArrayList<HashMap<String, String>> songsListData;
    private boolean userEnteredSearchString = false;

    // Songs playlist_item
    public ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
    public ArrayList<HashMap<String, String>> filteredSongsList = new ArrayList<HashMap<String, String>>();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.playlist);

        songsListData = new ArrayList<HashMap<String, String>>();

        final SongsManager songsManager = new SongsManager();
        // get all songs from SD card
        this.songsList = songsManager.getPlayList();

        createListViewUsingSongs();


        // Set up the layout elements for this activity
        editSearch = (EditText) findViewById(R.id.search);
        searchIcon = (ImageView) findViewById(R.id.search_icon);

        // Capture Text in EditText when user clicks search icon
        searchIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                String text = editSearch.getText().toString().toLowerCase(Locale.getDefault());
                filteredSongsList = songsManager.filter(text);
                userEnteredSearchString = true;
                createListViewUsingSongs();
            }
        });

        // selecting single ListView item
        ListView listView = getListView();
        // listening to single playlist_item item click
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                                            @Override
                                            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                                                // getting list item index
                                                int songIndex = position;

                                                // Starting new intent
                                                Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                                                // Sending songIndex to PlayerActivity
                                                intent.putExtra("songIndex", songIndex);
                                                setResult(100, intent);
                                                // Closing PlayListView
                                                finish();
                                            }
                                        }

        );
    }

    private void createListViewUsingSongs() {

        if (userEnteredSearchString) {
            // looping through playlist
            for (int i = 0; i < filteredSongsList.size(); i++){
                // creating new HashMap
                HashMap<String, String> song = songsList.get(i);
                // adding HashList to ArrayList
                songsListData.add(song);
            }
        } else {
            // looping through playlist
            for (int i = 0; i < songsList.size(); i++){
                // creating new HashMap
                HashMap<String, String> song = songsList.get(i);
                // adding HashList to ArrayList
                songsListData.add(song);
            }
        }

        // Adding menuItems to ListView
        adapter = new SimpleAdapter(this, songsListData,
                R.layout.playlist_item, new String[]{"songTitle"}, new int[]{
                R.id.songTitle});

        setListAdapter(adapter);
    }
}

导入android.app.ListActivity；
导入android.content.Intent；
导入android.os.Bundle；
导入android.view.view；
导入android.widget.AdapterView；
导入android.widget.EditText；
导入android.widget.ImageView；
导入android.widget.ListAdapter；
导入android.widget.ListView；
导入android.widget.simpledapter；
导入java.util.ArrayList；
导入java.util.HashMap；
导入java.util.Locale；
公共类播放活动扩展了ListActivity{
私人编辑文本编辑搜索；
私有图像视图搜索图标；
专用列表适配器；
私有ArrayList songsListData；
私有布尔值userEnteredSearchString=false；
//歌曲播放列表\u项
public ArrayList songsList=new ArrayList（）；
public ArrayList filteredSongsList=new ArrayList（）；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.playlist）；
songsListData=new ArrayList（）；
final SongsManager SongsManager=new SongsManager（）；
//从SD卡获取所有歌曲
this.songsList=songsManager.getPlayList（）；
createListViewUsingSongs（）；
//设置此活动的布局元素
editSearch=（EditText）findViewById（R.id.search）；
searchIcon=（ImageView）findViewById（R.id.search\u图标）；
//当用户单击搜索图标时捕获EditText中的文本
searchIcon.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图arg0）{
String text=editSearch.getText（）.toString（）.toLowerCase（Locale.getDefault（））；
filteredSongsList=songsManager.filter（文本）；
userEnteredSearchString=true；
createListViewUsingSongs（）；
}
});
//选择单个ListView项
ListView ListView=getListView（）；
//收听单个播放列表\u项目单击
setOnItemClickListener（新的AdapterView.OnItemClickListener（）{
@凌驾
public void onItemClick（AdapterView父对象、视图、整型位置、长id）{
//获取列表项索引
指数=位置；
//开始新的意图
Intent Intent=新的Intent（getApplicationContext（），MainActivity.class）；
//正在向PlayerActivity发送歌曲索引
intent.putExtra（“歌曲索引”，歌曲索引）；
setResult（100，意图）；
//关闭播放视图
完成（）；
}
}
);
}
私有void createListViewUsingSongs（）{
如果（userEnteredSearchString）{
//循环播放列表
对于（int i=0；i

SongsManager.java

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Locale;

public class SongsManager {

    private HashMap<String, String> song;
    private String songString;

    // SDCard Path
    final String MEDIA_PATH = "/storage/extSdCard/music";
    private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
    private ArrayList<HashMap<String, String>> filteredSongsList = new ArrayList<HashMap<String, String>>();


    // Constructors
    public SongsManager(String song) {
        this.songString = songString;
    }

    public SongsManager() {
    }

    /**
     * Function to read all mp3 files from sdcard
     * and store the details in ArrayList
     */
    public ArrayList<HashMap<String, String>> getPlayList() {
        File home = new File(MEDIA_PATH);

        if (home.listFiles(new FileExtensionFilter()).length > 0) {
            for (File file : home.listFiles(new FileExtensionFilter())) {
                HashMap<String, String> song = new HashMap<String, String>();
                song.put("songTitle", file.getName().substring(0, (file.getName().length() - 4)));
                song.put("songPath", file.getPath());

                // Adding each song to SongList
                songsList.add(song);
            }
        }
        // return songs playlist_item array
        return songsList;
    }

    public String getSong() {
        return this.songString;
    }

    /**
     * Class to filter files which are having .mp3 extension
     */
    class FileExtensionFilter implements FilenameFilter {
        public boolean accept(File dir, String name) {
            return (name.endsWith(".mp3") || name.endsWith(".MP3") || name.endsWith(".wma"));
        }
    }

    // Filter Class
    public ArrayList<HashMap<String, String>> filter(String searchString) {
        searchString = searchString.toLowerCase(Locale.getDefault());

        songsList.clear();
        songsList = getPlayList();

        //searchString is empty, so show all songs in results
        if (searchString.length() == 0) {

            if (filteredSongsList != null){
                filteredSongsList.clear();
            }
            filteredSongsList = songsList;
        }

        //only return songs that match the search string
        else {

            if (filteredSongsList != null){
                filteredSongsList.clear();
            }

            for (HashMap<String, String> song : songsList) {
                if (song != null) {
                    String songTitle = song.get("songTitle");
                    if (songTitle.toLowerCase().contains(searchString)) {
                        filteredSongsList.add(song);
                    }
                }
            }
        }

        return filteredSongsList;
    }
}

导入java.io.File；
导入java.io.FilenameFilter；
导入java.util.ArrayList；
导入java.util.HashMap；
导入java.util.Locale；
公共类歌曲管理器{
私家歌；
私人弦乐；
//SD卡路径
最终字符串MEDIA_PATH=“/storage/extSdCard/music”；
private ArrayList songsList=new ArrayList（）；
private ArrayList filteredSongsList=new ArrayList（）；
//建设者
公共歌曲管理器（弦乐歌曲）{
this.songString=songString；
}
公共歌曲管理器（）{
}
/**
*从SD卡读取所有mp3文件的功能
*并将详细信息存储在ArrayList中
*/
公共阵列列表getPlayList（）{
文件主目录=新文件（媒体路径）；
if（home.listFiles（新文件扩展筛选器（））.length>0）{
对于（文件：home.listFiles（新的FileExtensionFilter（）））{
HashMap宋=新HashMap（）；
song.put（“songTitle”，file.getName（）.substring（0，（file.getName（）.length（）-4））；
put（“songPath”，file.getPath（））；
//将每首歌曲添加到歌曲列表
歌曲列表。添加（歌曲）；
}
}
//返回歌曲播放列表\项目数组
返回歌曲列表；
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    <EditText
        android:id="@+id/search"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="4"
        android:hint="Type song &amp; click search icon"
        android:inputType="text"
        android:maxLength="40">
        <requestFocus />
    </EditText>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/search_icon"
        android:layout_weight="1"
        android:src="@drawable/ic_search"/>

    </LinearLayout>

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:divider="#242424"
        android:dividerHeight="1dp"
        android:listSelector="@drawable/list_selector" />

</LinearLayout>

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Locale;

public class PlayListActivity extends ListActivity {

    private EditText editSearch;  //search text input by user
    private ImageView searchIcon;
    public SimpleAdapter simpleAdapter;
    private ListView listView;
    private ArrayList<HashMap<String, String>> songsListData;
    public ArrayList<HashMap<String, String>> songsList = new ArrayList<>();  //stores all the songs
    public ArrayList<HashMap<String, String>> filteredSongsList = new ArrayList<>();  //stores songs that match search
    private int songsAddedCounter = 0;  //counter for debugging -> are songs being added to list?

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.playlist);

        // Set up the layout elements for this activity
        editSearch = (EditText) findViewById(R.id.search);
        searchIcon = (ImageView) findViewById(R.id.search_icon);

        songsListData = new ArrayList<>();  //Stores all the songs to put into ListView

        final SongsManager songsManager = new SongsManager();
        // get all songs from SD card
        this.songsList = songsManager.getPlayList();  //gets all the songs from the phone and puts them in the HashMap

        createListViewUsingSongs();  //draws the ListView on the screen using the songsList HashMap

        // selecting single ListView item
        listView = getListView();

        // listening to single playlist_item item click
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                                            @Override
                                            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                                                int songIndex = position; // getting list item index

                                                // Starting new intent
                                                Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                                                // Sending songIndex to PlayerActivity
                                                intent.putExtra("songIndex", songIndex);
                                                setResult(100, intent);
                                                // Closing PlayListView
                                                finish();
                                            }
                                        }

        );

        /**
         * When user clicks search icon, execute a search, then update the ListView simpleAdapter
         */
        searchIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                String text = editSearch.getText().toString().toLowerCase(Locale.getDefault());
                filteredSongsList = songsManager.filter(text);
                updateListViewUsingSongs();
            }
        });
    }

    private void createListViewUsingSongs() {
        // looping through playlist
        for (int i = 0; i < songsList.size(); i++) {
            // creating new HashMap
            HashMap<String, String> song = songsList.get(i);
            // adding HashList to ArrayList
            songsListData.add(song);

        }

        // Adding menuItems to ListView
        simpleAdapter = new SimpleAdapter(this, songsListData,
                R.layout.playlist_item, new String[]{"songTitle"}, new int[]{
                R.id.songTitle});

        setListAdapter(simpleAdapter);
    }

    private void updateListViewUsingSongs() {

        songsAddedCounter = 0;
        songsListData.clear();  //super important that we start from zero, and add only the filtered songs!

        // looping through playlist
        for (int i = 0; i < filteredSongsList.size(); i++) {
            // creating new HashMap
            HashMap<String, String> song = filteredSongsList.get(i);
            // adding HashList to ArrayList
            songsListData.add(song);
            songsAddedCounter++;
        }
        Toast.makeText(getApplicationContext(), "Search results: " + songsAddedCounter + " songs", Toast.LENGTH_SHORT).show();

        simpleAdapter = null;

        simpleAdapter = new SimpleAdapter(this, songsListData,
                R.layout.playlist_item, new String[]{"songTitle"}, new int[]{
                R.id.songTitle});


        setListAdapter(simpleAdapter);
        simpleAdapter.notifyDataSetChanged();
    }
}