The initState
method is called once when the widget is inserted into the tree. It’s used to initialize variables and perform other setup tasks that need to happen once, when the widget is created.
It’s important to call setState
inside initState
because it triggers a rebuild of the widget and ensures that any changes made to the widget’s state during initState
will be reflected in the UI.
If you don’t call setState
after making changes to the state inside initState
, the changes won’t be reflected in the UI, and you may encounter bugs or unexpected behavior.
Here’s an example of calling setState
inside initState
:
class MyWidget extends StatefulWidget {
@override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
int _counter = 0;
@override
void initState() {
super.initState();
_counter = 1;
setState(() {});
}
@override
Widget build(BuildContext context) {
return Text('Counter: $_counter');
}
}
In this example, _counter
is initialized to 1
in initState
, and setState
is called to trigger a rebuild of the widget. This ensures that the change to _counter
will be reflected in the UI.