想問下在3-1章節中有兩處“mHandler.postDelayed(new MyRunnable(), 2000);”，請問，分別的含義有什么不同？？

class?MyRunnable?implements?Runnable?{

????@Override
????public?void?run()?{
????????index++;
????????index?=?index?%?4;
????????mImageView.setImageResource(images[index]);

????????mHandler.postDelayed(new?MyRunnable(),?2000);
????}
}

@Override
protected?void?onCreate(Bundle?savedInstanceState)?{
????super.onCreate(savedInstanceState);
????setContentView(R.layout.activity_main);

????mTextView?=?(TextView)?findViewById(R.id.textview);
????mImageView?=?(ImageView)?findViewById(R.id.imageView);

????mHandler.postDelayed(new?MyRunnable(),?2000);