await and Future.delayed trong flutter

void createOrderMessage () async {
  print('Run createOrderMessage...');
  var order = await getUserOrder();
  print('Your order is: $order');
}

Future<String> getUserOrder() {
  // Imagine that this function is more complex and slow.
  return Future.delayed(Duration(seconds: 30), () => 'Large Latte');
}

main() async {
  await createOrderMessage();
  countSeconds(4);
 
}

// You can ignore this function - it's here to visualize delay time in this example.
void countSeconds(s) {
  print('Run countSeconds()...');
  for( var i = 1 ; i <= s; i++ ) {
      Future.delayed(Duration(seconds: i), () => print(i));
   }
}

Ket Qua :

Run createOrderMessage... Your order is: Large Latte Run countSeconds()... 1 2 3 4

timer trong flutter

Future.delayed(const Duration(milliseconds: 750), () {
  flag =!flag ;
});

Thay đổi 1 giá trị trước khi load lại toàn bọ trang in flutter

setState(() {
  like = !like;
  if (like)
    dataArray[dataArray.indexOf(item)].likecount++;
  else    dataArray[dataArray.indexOf(item)].likecount-- >= 0;
});