三秒后跳转

 private Handler mHandler = new Handler(new Handler.Callback() {
      @Override
      public boolean handleMessage(Message msg) {
          if (msg!=null){

              Intent intent = new Intent(MainActivity.this,GuidePage.class);
              startActivity(intent);

          }
          return true;

      }
  });
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        new Thread(){
            @Override
            public void run() {
                super.run();
                Message message = new Message();
                mHandler.sendMessageDelayed(message,3000);
            }
        }.start();
    }