Android Listview不以片段形式填充sd卡中的歌曲

我正在制作一个应用程序，它可以从sd卡上获取歌曲，然后 在listview中填充。但由于某些原因，它不会填充和显示 空白片段。你能帮忙吗？这可能是什么原因造成的 问题多谢各位

bellasongs.java

public class BellaSongs extends ListFragment {

    private ArrayList<ModelBellaSongs> BellaSongList;
    private ListView Bellasongviews;
    Context context;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootview = inflater.inflate(R.layout.bella_songs, container, false);
        Bellasongviews = (ListView)rootview.findViewById(android.R.id.list);

        BellaSongList = new ArrayList<ModelBellaSongs>();
        return rootview;
    }

    public void getBellaSongList() {
        ContentResolver musicResolver = context.getContentResolver();
        Uri musicUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);

        if (musicCursor != null && musicCursor.moveToFirst()) {
            int titlecolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
            int idcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media._ID);
            int artistcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);

            do {
                long thisId = musicCursor.getLong(idcolumn);
                String thistitle = musicCursor.getString(titlecolumn);
                String thisartist = musicCursor.getString(artistcolumn);
                BellaSongList.add(new ModelBellaSongs(thisId, thistitle, thisartist));
            } while (musicCursor.moveToNext());
        }
        getBellaSongList();

        Collections.sort(BellaSongList, new Comparator<ModelBellaSongs>() {
            @Override
            public int compare(ModelBellaSongs a, ModelBellaSongs b) {
                return a.getTitle().compareTo(b.getTitle());
            }
        });

        BellaSongsAdapter bellasongsadapter = new BellaSongsAdapter(getActivity(),BellaSongList);
            Bellasongviews.setAdapter(bellasongsadapter);
    }
}

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">


<ListView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@android:id/list"
    android:layout_gravity="center_vertical"
    android:layout_weight="1" />

 </LinearLayout>

public class BellaSongsAdapter extends BaseAdapter {

    private ArrayList<ModelBellaSongs> bellasongs;
    private LayoutInflater songdetails;

    public BellaSongsAdapter(Context c, ArrayList<ModelBellaSongs>thesongs){
        bellasongs = thesongs;
        songdetails = LayoutInflater.from(c);
    }

    @Override
    public int getCount() {
        return bellasongs.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LinearLayout songLayout=(LinearLayout)songdetails.inflate(R.layout.singlelist_item,parent,false);
        TextView titleview=(TextView)songLayout.findViewById(R.id.text_song_name);
        TextView artistview=(TextView)songLayout.findViewById(R.id.text_artist_name);

        ModelBellaSongs currentsongs = bellasongs.get(position);
        titleview.setText(currentsongs.getTitle());
        artistview.setText(currentsongs.getArtist());
        songLayout.setTag(position);

        return songLayout;
    }
}

public类扩展ListFragment{
私人ArrayList BellaSongList；
私有列表视图；
语境；
@凌驾
已创建ActivityState上的公共无效（Bundle savedInstanceState）{
super.onActivityCreated（savedInstanceState）；
}
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
视图根视图=充气器。充气（R.layout.bella_歌曲，容器，false）；
Bellasongviews=（ListView）rootview.findViewById（android.R.id.list）；
BellaSongList=新的ArrayList（）；
返回rootview；
}
public void getBellaSongList（）{
ContentResolver musicResolver=context.getContentResolver（）；
Uri musicUri=MediaStore.Audio.Media.EXTERNAL\u CONTENT\u Uri；
游标musicCursor=musicSolver.query（musicUri，null，null，null）；
if（musicCursor！=null&&musicCursor.moveToFirst（））{
int titlecolumn=musicCursor.getColumnIndex（MediaStore.Audio.Media.TITLE）；
int ID column=musicCursor.getColumnIndex（MediaStore.Audio.Media.\u ID）；
int-artistcolumn=musicCursor.getColumnIndex（MediaStore.Audio.Media.ARTIST）；
做{
long thisId=musicCursor.getLong（idcolumn）；
String thisttitle=musicCursor.getString（titlecolumn）；
String thisartist=musicCursor.getString（artistcolumn）；
添加（新的模式BellaSongs（thisId，thistitle，thisartist））；
}while（musicCursor.moveToNext（））；
}
getSongList（）；
Collections.sort（BellaSongList，newcomparator（）{
@凌驾
公共整数比较（ModelBella歌曲a、ModelBella歌曲b）{
返回a.getTitle（）.compareTo（b.getTitle（））；
}
});
BellaSongsAdapter BellaSongsAdapter=新的BellaSongsAdapter（getActivity（），BellaSongList）；
setAdapter（bellasongsadapter）；
}
}

adapter.java

public class BellaSongs extends ListFragment {

    private ArrayList<ModelBellaSongs> BellaSongList;
    private ListView Bellasongviews;
    Context context;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootview = inflater.inflate(R.layout.bella_songs, container, false);
        Bellasongviews = (ListView)rootview.findViewById(android.R.id.list);

        BellaSongList = new ArrayList<ModelBellaSongs>();
        return rootview;
    }

    public void getBellaSongList() {
        ContentResolver musicResolver = context.getContentResolver();
        Uri musicUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);

        if (musicCursor != null && musicCursor.moveToFirst()) {
            int titlecolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
            int idcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media._ID);
            int artistcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);

            do {
                long thisId = musicCursor.getLong(idcolumn);
                String thistitle = musicCursor.getString(titlecolumn);
                String thisartist = musicCursor.getString(artistcolumn);
                BellaSongList.add(new ModelBellaSongs(thisId, thistitle, thisartist));
            } while (musicCursor.moveToNext());
        }
        getBellaSongList();

        Collections.sort(BellaSongList, new Comparator<ModelBellaSongs>() {
            @Override
            public int compare(ModelBellaSongs a, ModelBellaSongs b) {
                return a.getTitle().compareTo(b.getTitle());
            }
        });

        BellaSongsAdapter bellasongsadapter = new BellaSongsAdapter(getActivity(),BellaSongList);
            Bellasongviews.setAdapter(bellasongsadapter);
    }
}

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">


<ListView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@android:id/list"
    android:layout_gravity="center_vertical"
    android:layout_weight="1" />

 </LinearLayout>

public class BellaSongsAdapter extends BaseAdapter {

    private ArrayList<ModelBellaSongs> bellasongs;
    private LayoutInflater songdetails;

    public BellaSongsAdapter(Context c, ArrayList<ModelBellaSongs>thesongs){
        bellasongs = thesongs;
        songdetails = LayoutInflater.from(c);
    }

    @Override
    public int getCount() {
        return bellasongs.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LinearLayout songLayout=(LinearLayout)songdetails.inflate(R.layout.singlelist_item,parent,false);
        TextView titleview=(TextView)songLayout.findViewById(R.id.text_song_name);
        TextView artistview=(TextView)songLayout.findViewById(R.id.text_artist_name);

        ModelBellaSongs currentsongs = bellasongs.get(position);
        titleview.setText(currentsongs.getTitle());
        artistview.setText(currentsongs.getArtist());
        songLayout.setTag(position);

        return songLayout;
    }
}

bellasongsadapter.java

public class BellaSongs extends ListFragment {

    private ArrayList<ModelBellaSongs> BellaSongList;
    private ListView Bellasongviews;
    Context context;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootview = inflater.inflate(R.layout.bella_songs, container, false);
        Bellasongviews = (ListView)rootview.findViewById(android.R.id.list);

        BellaSongList = new ArrayList<ModelBellaSongs>();
        return rootview;
    }

    public void getBellaSongList() {
        ContentResolver musicResolver = context.getContentResolver();
        Uri musicUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);

        if (musicCursor != null && musicCursor.moveToFirst()) {
            int titlecolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
            int idcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media._ID);
            int artistcolumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);

            do {
                long thisId = musicCursor.getLong(idcolumn);
                String thistitle = musicCursor.getString(titlecolumn);
                String thisartist = musicCursor.getString(artistcolumn);
                BellaSongList.add(new ModelBellaSongs(thisId, thistitle, thisartist));
            } while (musicCursor.moveToNext());
        }
        getBellaSongList();

        Collections.sort(BellaSongList, new Comparator<ModelBellaSongs>() {
            @Override
            public int compare(ModelBellaSongs a, ModelBellaSongs b) {
                return a.getTitle().compareTo(b.getTitle());
            }
        });

        BellaSongsAdapter bellasongsadapter = new BellaSongsAdapter(getActivity(),BellaSongList);
            Bellasongviews.setAdapter(bellasongsadapter);
    }
}

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">


<ListView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@android:id/list"
    android:layout_gravity="center_vertical"
    android:layout_weight="1" />

 </LinearLayout>

public class BellaSongsAdapter extends BaseAdapter {

    private ArrayList<ModelBellaSongs> bellasongs;
    private LayoutInflater songdetails;

    public BellaSongsAdapter(Context c, ArrayList<ModelBellaSongs>thesongs){
        bellasongs = thesongs;
        songdetails = LayoutInflater.from(c);
    }

    @Override
    public int getCount() {
        return bellasongs.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LinearLayout songLayout=(LinearLayout)songdetails.inflate(R.layout.singlelist_item,parent,false);
        TextView titleview=(TextView)songLayout.findViewById(R.id.text_song_name);
        TextView artistview=(TextView)songLayout.findViewById(R.id.text_artist_name);

        ModelBellaSongs currentsongs = bellasongs.get(position);
        titleview.setText(currentsongs.getTitle());
        artistview.setText(currentsongs.getArtist());
        songLayout.setTag(position);

        return songLayout;
    }
}

公共类BellaSongsAdapter扩展BaseAdapter{
私人ArrayList bellasongs；
私人停车场详细信息；
公共BellaSongsAdapter（上下文c，数组列表歌曲）{
贝拉歌曲=歌曲；
songdetails=Layoutiner.from（c）；
}
@凌驾
public int getCount（）{
返回bellasongs.size（）；
}
@凌驾
公共对象getItem（int位置）{
返回null；
}
@凌驾
公共长getItemId（int位置）{
返回0；
}
@凌驾
公共视图getView（int位置、视图转换视图、视图组父视图）{
LinearLayout songLayout=（LinearLayout）songdetails.inflate（R.layout.singlelist_项，父项，false）；
TextView titleview=（TextView）songLayout.findViewById（R.id.text\u song\u name）；
TextView artistview=（TextView）songLayout.findViewById（R.id.text\u artist\u name）；
ModelBellaSongs currentsongs=bellasongs.get（位置）；
titleview.setText（currentsongs.getTitle（））；
artistview.setText（currentsongs.getArtister（））；
songLayout.setTag（位置）；
返回布局；
}
}

我认为您的id引用不正确

Bellasongviews = (ListView)rootview.findViewById(android.R.id.list);

确保您的this

android.R.id.list

id正确，它应该从

R.id.yourId

不要在这里导入android.R在这里导入您的项目

---

检查您的XML布局文件的id或将其粘贴到您的问题中。

我认为您的id引用不正确

Bellasongviews = (ListView)rootview.findViewById(android.R.id.list);

确保您的this

android.R.id.list

id正确，它应该从

R.id.yourId

不要在这里导入android.R在这里导入您的项目

---

检查XML布局文件的id或将其粘贴到您的问题中。

查看您的代码，我看到了getBellaSingList（）方法。该方法检索数据，甚至重复调用自身，但它不会在

onCreateView（）中调用。

。因此，从技术上讲，您不是在填充数据集。您需要在初始化视图时调用它-请验证此方法的逻辑。

查看您的代码，我看到了getBellaSingList（）方法。此方法正在检索数据，甚至重复调用自己，但它不会在

onCreateView（）中调用。

。因此，从技术上讲，您不是在填充数据集。您需要在初始化视图时调用它-请验证此方法的逻辑。

返回的游标不是空的吗？请附上BellaSongsAdapter。class@YuriiTsap这里我添加了适配器类。是否正确。返回的游标不为空？请附上BellaSongsAdapter。class@YuriiTsap这里我添加了适配器类。是否正确。之前我使用了R.id.customid，但在运行时它引发了一个异常，即id应该包含在R.id.customid之后的android。我添加了xml。我在songs.java中将id从

android.R.id.list

更改为

R.id.list

，但最终在xml中从

android:id/list

更改为

@+id/list

，但在运行时它仍然没有填充listview。之前我使用了R.id.customid，但在运行时它抛出了一个异常，即id应该包括android在R.id.customid之后，我添加了xml。我在songs.java中将id从

android.R.id.list

更改为

R.id.list

，但最终在xml中从

android:id/list

更改为

@+id/list

，但它仍然没有填充ru中的列表视图