delay after setState is triggered

محمدرضا حجتی 0
Viewed 39

in the code below that is for throwing dice, I want to wait 2 seconds after each dice throwing. I tested sleep(duration) and await Future.delayed(duration); the first one makes a delay before updating the screen which means when I tap the TextButton, it waits for 2 seconds and then changes the screen, but I want it to be changed and then waits for 2 seconds. The second one actually does nothing and there is no delays. Here is the code:

Duration delay = const Duration(seconds: 2);

enter image description here

delay sequential flutter
2 Answers

You can call delay inside WidgetsBinding, like this:

setState(() {
             ...
});
WidgetsBinding.instance.addPostFrameCallback((_) async {
  await Future.delayed(Duration(seconds: 2));
  print("call"); // update the view then print call after 2 second
});
eamirho3ein0

try..

//Move your onPressCode to a function

Future<void> rollDice() async{
  
  await Future.delayed(Duration(milliseconds: 0), () {
     /// your onPressCode
  });
}

And on your onPress :

onPressed:() async {
  await rollDice();
  await Future.delayed(Duration(milliseconds: 2000), () {});
  print('this print is show after 2 secs');
}

Edit ...

For prevent double tap, you can create a state called canPress with default value = false ...

onPressed:() async {
  if (canPress){
    setState(() => canPress = false);
    await rollDice();
    await Future.delayed(Duration(milliseconds: 2000), () {});
    print('this print is show after 2 secs');
    setState(() => canPress = true);  
  }
}
Sergio Clemente0
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