查询模拟器文件夹和文件使用listview展示

 @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        listview = (ListView) findViewById(R.id.listview);        File file = Environment.getExternalStorageDirectory();        String state = Environment.getExternalStorageState();        String path = file.getPath();        showfile(path);    }

    private void showfile(String path) {        File file = new File(path);        File[] files = file.listFiles();        List<String> list = new ArrayList<>();        if (null != files) {            for (int i = 0; i < files.length; i++) {                list.add(files[i].getName());//                Log.d("123456", files[i].getName());                if (files[i].isDirectory()) {                    showfile(files[i].getAbsolutePath());                }            }        }        ListAdapter la = new ListAdapter(MainActivity.this, list);        listview.setAdapter(la);    }