试试这个，

 String[] fileList;
    File videoFiles = new File(Environment.getExternalStorageDirectory()+"/myfolder");

    if(videoFiles.isDirectory())
    {
        fileList=videoFiles.list();
    }

   for(int i=0;i<fileList.length;i++)
   {
       Log.e("Video:"+i+" File name",fileList[i]);
   }