CODEWITHSUNDEEP
flutterdart
simo9900
simo9900

Reputation: 133

callback function called before executing it in the second page

I have in my main page a Container which use as child a widget PageView with a callback function onBookPlace.

Container(
  child: PageView(
  onBookPlace: onBookPlace(
   dateStart, dateEnd
  ),
  ),
 )

In my PageView, I have the function onBookPlace which should be called when I press onTap

class PageView extends StatelessWidget {

  final VoidCallback onBookPlace;

  const PageView({Key key,this.onBookPlace})
      : super(key: key);
  @override
  Widget build(BuildContext context) {
     return GestureDetector(
     onTap:() {onBookPlace()},
                                 
   );}}

But the problem here is my function is called before I click over the GestureDetector widget. It's called on the construction of the PageView.

How to fix this? I mean that the callback should only be called when I click over the GestureDetector widget.

Thank you

Upvotes: 0

Views: 110

Answers (1)

Bibipkins
Bibipkins

Reputation: 471

I think you should pass a reference to your function, instead of calling it right away. So you probably should remove ()

Container(
  child: PageView1(onBookPlace: onBookPlace)
)

EDIT: if you want to pass some parameters with your function then you can create another function to pass as your callback. For example you can use anonymous function.

Container(
   child: PageView1(onBookPlace: () => onBookPlace(dateStart, dateEnd))
)

The basic idea is that when you want to pass a callback function you want to pass the function itself, not its result. By putting parentheses there you call the function and pass its result, instead of passing a reference to your handler function.

Upvotes: 2

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