Flutter onClosing callback for showModalBottomSheet

Question

I have a showModalBottomSheet like the below, which I understand to inherit from BottomSheet (right?)

      showModalBottomSheet<void>(         context: context,         builder: (BuildContext context) {           return Container(             height: 260.0,             child: Text('I am text')           );         },       ); 

What I want to do:

I want to know (listen) when the modal is being closed, and act on it.

I've seen this onClosing callback: https://docs.flutter.io/flutter/material/BottomSheet/onClosing.html

How can I have a listener attached to the showModalBottomSheet, and then act accordingly when it fires?

Answer 1

You can also achieve it by use of whenComplete function of showModalBottomSheet.

Let's see below code

showModalBottomSheet<void>(         context: context,         builder: (BuildContext context) {           return Container(             height: 260.0,             child: Text('I am text')         );       }, ).whenComplete(() {   print('Hey there, I\'m calling after hide bottomSheet'); }); 

Answer 2

Perhaps it's not the best solution, but showModalBottomSheet return a "Future" so you can used it.

For example:

void _showModal() {     Future<void> future = showModalBottomSheet<void>(       context: context,       builder: (BuildContext context) {         return Container(height: 260.0, child: Text('I am text'));       },     );     future.then((void value) => _closeModal(value)); } void _closeModal(void value) {     print('modal closed'); }