/**
  * 從本地的sdcard得到數(shù)據(jù)
  * //1.遍歷sdcard,后綴名
  * //2.從內容提供者里面獲取視頻
  * //3.如果是6.0的系統(tǒng)，動態(tài)獲取讀取sdcard的權限
  */
 private void getDataFromLocal() {

  new Thread(){
   @Override
   public void run() {
    super.run();

//    isGrantExternalRW((Activity) context);
//    SystemClock.sleep(2000);
    mediaItems = new ArrayList<>();
    ContentResolver resolver = context.getContentResolver();
    Uri uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
    String[] objs = {
      MediaStore.Video.Media.DISPLAY_NAME,//視頻文件在sdcard的名稱
      MediaStore.Video.Media.DURATION,//視頻總時長
      MediaStore.Video.Media.SIZE,//視頻的文件大小
      MediaStore.Video.Media.DATA,//視頻的絕對地址
      MediaStore.Video.Media.ARTIST,//歌曲的演唱者

    };
    Cursor cursor = resolver.query(uri, objs, null, null, null);
    if(cursor != null){
     while (cursor.moveToNext()){

      MediaItem mediaItem = new MediaItem();

      mediaItems.add(mediaItem);//寫在上面

      String name = cursor.getString(0);//視頻的名稱
      mediaItem.setName(name);

      long duration = cursor.getLong(1);//視頻的時長
      mediaItem.setDuration(duration);

      long size = cursor.getLong(2);//視頻的文件大小
      mediaItem.setSize(size);

      String data = cursor.getString(3);//視頻的播放地址
      mediaItem.setData(data);

      String artist = cursor.getString(4);//藝術家
      mediaItem.setArtist(artist);



     }

     cursor.close();


    }


    //Handler發(fā)消息
    handler.sendEmptyMessage(10);


   }
  }.start();

 }

 /**
  * 解決安卓6.0以上版本不能讀取外部存儲權限的問題
  * @param activity
  * @return
  */
 public static boolean isGrantExternalRW(Activity activity) {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && activity.checkSelfPermission(
    Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

   activity.requestPermissions(new String[]{
     Manifest.permission.READ_EXTERNAL_STORAGE,
     Manifest.permission.WRITE_EXTERNAL_STORAGE
   }, 1);

   return false;
  }

  return true;
 }