SearchView不更新项目，只更新文本

Question

我正在使用SearchView来过滤音乐项目。但当我搜索一个项目时，歌曲的标题会更新，但不会更新实际的歌曲。最初我有listSongs=musicFiles，它有效，但没有更新项目，只有标题。然后我将其更改为listSongs=mFiles，这将抛出一个nullPointerException。

音乐适配器

public class MusicAdapter extends RecyclerView.Adapter<MusicAdapter.MyVieHolder> {
private Context mContext;
static ArrayList<MusicFiles> mFiles = new ArrayList<>();
MusicAdapter(Context mContext, ArrayList<MusicFiles> mFiles){
MusicAdapter.mFiles = mFiles;
this.mContext = mContext;
}
@NonNull
@Override
public MyVieHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.music_items, parent, false);
return new MyVieHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyVieHolder holder, final int position) {
holder.file_name.setText(mFiles.get(position).getTitle());
byte[] image = getAlbumArt(mFiles.get(position).getPath());
if (image != null){
Glide.with(mContext).asBitmap()
.load(image)
.into(holder.album_art);
}
else{
Glide.with(mContext).asBitmap()
.load(R.drawable.something_3)
.into(holder.album_art);
}
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, MainActivity.class);
intent.putExtra("position" , position);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mContext.startActivity(intent);
notifyDataSetChanged();
}
});
}
@Override
public int getItemCount() {
return mFiles.size();
}
public class MyVieHolder extends RecyclerView.ViewHolder{
TextView file_name;
ImageView album_art;
public MyVieHolder(@NonNull View itemView) {
super(itemView);
file_name = itemView.findViewById(R.id.music_file_name);
album_art = itemView.findViewById(R.id.music_img);
}
}
private byte[] getAlbumArt(String uri){
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
retriever.setDataSource(uri);
byte[] art = retriever.getEmbeddedPicture();
retriever.release();
return art;
}
public void updateList(ArrayList<MusicFiles> musicFilesArrayList){
mFiles = new ArrayList<>();
mFiles.addAll(musicFilesArrayList);
notifyDataSetChanged();

}

主要活动

这是我遇到问题的代码

public void getInentMethod() {
position = getIntent().getIntExtra("position", 0);
listSongs = mFiles;                                       //bug occurs when listSongs = mFiles
if (listSongs != null) {
playBtn.setBackgroundResource(R.drawable.ic_pause);
uri = Uri.parse(listSongs.get(position).getPath());
}
if (mediaPlayer != null) {
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = MediaPlayer.create(getApplicationContext(), uri);
mediaPlayer.start();
}
else {
mediaPlayer = MediaPlayer.create(getApplicationContext(), uri);
playBtn.setBackgroundResource(R.drawable.ic_play);
mediaPlayer.stop();
}
seekBar.setMax(mediaPlayer.getDuration()/1000);
metaData(uri);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.search, menu);
MenuItem menuItem = menu.findItem(R.id.search_option);
SearchView searchView = (SearchView) menuItem.getActionView();
searchView.setOnQueryTextListener(this);
return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onQueryTextSubmit (String query){
return false;
}
@Override
public boolean onQueryTextChange (String newText){
String userInput = newText.toLowerCase();
ArrayList<MusicFiles> musicFilesArrayList = new ArrayList<>();
for (MusicFiles mFiles : musicFiles){
if(mFiles.getTitle().toLowerCase().contains(userInput)){
musicFilesArrayList.add(mFiles);
}
}
musicAdapter.updateList(musicFilesArrayList);
return true;
}

当listSongs=mFiles我收到nullPointerException时，uri参数不能为null。我不知道是什么原因造成的？

我还收到IndexOutOfBoundsException。

由以下原因引起：java.lang.IndexOutOfBoundsException：索引：0，大小：0。

任何帮助都将不胜感激。

Answer 1

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/search_bar"
android:title="search"
android:icon="@drawable/ic_baseline_search_24"
app:showAsAction="always|collapseActionView"
app:actionViewClass="android.widget.SearchView" />

</menu>

内部创建选项菜单

getMenuInflater().inflate(R.menu.main_menu,menu);
MenuItem searchItem=menu.findItem(R.id.search_bar);
MenuItem settingsItem=menu.findItem(R.id.action_settings);
SearchView searchView= (SearchView) searchItem.getActionView();
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
//do filter here
adapter.getFilter().filter(newText);
return false;
}
});
return true;
}
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
if (item.getItemId()==R.id.search_bar) return true;
return super.onOptionsItemSelected(item);
}

在Adapter类中，创建两个数组列表

class Adapter implements Filterable{
private List<TotalItems> totalItems;              //original
private List<TotalItems> totalItemsAll;           //copy
Context context;
public Adapter(ArrayList<TotalItems> totalItems,Context context){
this.totalItems=totalItems;
this.context=context;
this.totalItemsAll=new ArrayList<>(totalItems);
}

@Override
public Filter getFilter() {
return filter;
}
private Filter filter=new Filter() {
@Override
protected FilterResults performFiltering(CharSequence charSequence) {
//TotalItems is my model class
List<TotalItems> filteredList=new ArrayList<>();
if (charSequence==null||charSequence.length()==0)
filteredList.addAll(totalItemsAll);
else {
String filterPattern=charSequence.toString().toLowerCase().trim();
for (TotalItems productList:totalItemsAll){
if (productList.getiName().toLowerCase().contains(filterPattern)){
filteredList.add(productList);
}else Toast.makeText(context,"No results found",Toast.LENGTH_LONG).show();
}
}
FilterResults filterResults=new FilterResults();
filterResults.values=filteredList;
return filterResults;
}
@Override
protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
totalItems.clear();
totalItems.addAll((List)filterResults.values);
notifyDataSetChanged();
}
};
}

让我知道这是否适合你