android - APK 适用于三星，但在 Nexus 中出现 2 个错误？

Question

在我的应用程序中，首先创建一个 NewFolder，然后我录制音频并将它们保存在这个新文件夹中。
我还有一个 ArrayList 来显示我的记录
我在这里创建 NewFolder

        int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
    String sep = File.separator; // Use this instead of hardcoding the "/"
    String newFolder = "FolderName";
    String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
    File myNewFolder = new File(extStorageDirectory + sep + newFolder);
    //myNewFolder.mkdir();
    myNewFolder.mkdirs();


    while (fs.getfetchstatus() != true) {
        mySongs = fs.findSongs(Environment.getExternalStorageDirectory()); 
              //>>>>>>>>>>HERE IS HAVING ANY ERROR<<<<<<<<<


    }
    if (mySongs != null) {
        dialog.dismiss();
    }
    mySongs = fs.getsonglist();

    items = new String[mySongs.size()];
    for (int i = 0; i < mySongs.size(); i++) {
        items[i] = mySongs.get(i).getName().toString().replace(".3gp", "");

    }
    final ArrayAdapter<String> adp = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, items);
    adp.notifyDataSetChanged();
    lv.setAdapter(adp);

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Intent intent = new Intent(getApplicationContext(), Player.class);
            intent.putExtra("pos", i);
            adp.notifyDataSetChanged();
            startActivity(intent);
            finish();
        }
    });

这是我的 ArrayList

     boolean fetchstatus=false;
ArrayList<File> songs=new ArrayList<File>();

String sep = File.separator; // Use this instead of hardcoding the "/"
String newFolder = "FolderName";
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
File myNewFolder = new File(extStorageDirectory + sep + newFolder);

//File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
FetchSongs(){

}
public ArrayList<File> findSongs(File root){

    ArrayList<File> al=new ArrayList<File>();
   // File[] files=root.listFiles();

    //File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
    File file = new File(Environment.getExternalStorageDirectory(), newFolder);
    File[] files = file.listFiles();


    for (File singleFile : files){
        if(singleFile.isDirectory() && !singleFile.isHidden()){
            al.addAll(findSongs(singleFile));
    //>>>>>>>ERROR HERE<<<<<<<<<<<<<<<<<<<

        }
        else {
            if(singleFile.getName().endsWith(".mp3")){
                al.add(singleFile);
            }
        }
    }

    fetchstatus=true;
    songs=al;
    return al;

}

我有这些错误

     java.lang.RuntimeException: Unable to start activity ComponentInfo
    at org.usr.usr.musicplayer.FetchSongs.findSongs(FetchSongs.java:35)
                                                                   at org.usr.usr.musicplayer.MainActivity.onCreate(MainActivity.java:124)

Answer 1

也许只是这行错误

File file = new File(Environment.getExternalStorageDirectory(), newFolder);

Nexus 并不总是有外部存储，但为了更准确，您应该检查跟踪错误，很可能您能够看到导致运行时错误的确切行