How to add a null value on a list of ? null cant be added because flutter null safety

Question

I'm creating a drawing app using flutter. I've used gesturedetector onpanstart, onpanend, onpanupdate. But I have to close the array of offsets. Because of null safety I am not able to use 'null'. how can I add a null value on the List or end up the list somehow. or any other ways to make a drawing app using flutter.

onPanEnd:(details){setState((){drawingPoints.add(null!);});}

`final List list = []; list.add(Offset(1,2)); list.add(null);` — pskink, Dec 14 '21 at 17:33
null can't be added as a value of offset, because of flutter null safety added. — dev-ruman, Dec 19 '21 at 17:27

score 0 · Answer 1 · answered Dec 14 '21 at 17:34

0

To clear the available data in your List use .clear() or to assign a null value simply assign null to it

onPanEnd:(details){setState((){drawingPoints = null;});} // to assign null

onPanEnd:(details){setState((){drawingPoints.clear();});} // to clear the data

answered Dec 14 '21 at 17:34

Diwyansh

2,961
1
7
11

both are not working. – dev-ruman Dec 19 '21 at 17:55
you need to show your full code because both are working for me, so you need to share your code. – Diwyansh Dec 19 '21 at 19:28

How to add a null value on a list of ? null cant be added because flutter null safety

1 Answers1