initState in Flutter
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In Flutter, initState is a inital/beginning method of StatefulWidget.
“This method is invoked only once during the widget’s lifecycle”, It means when you open StatefulWidget based screen there is initial value allocation to variables or method calling, whatever we mentioned inside initState method first allocated values and then the screen opens.
@override
void initState() {
//Calling superclass (State)
super.initState();
// Initialization counter value 42
counter = 42;
print('initState called');
//method Calling at initial level
testMethod();
}
It’s a common practice to call super.initState() within this method to ensure that the initialization of the state is properly handled by the superclass (State) or parent class
![What is initState What is initState](https://researchthinker.com/wp-content/uploads/2023/12/What-is-initState.png)
Code:
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyStatefulWidget(),
);
}
}
class MyStatefulWidget extends StatefulWidget {
@override
_MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
// Declare variable
int counter = 0;
@override
void initState() {
//Calling superclass (State)
super.initState();
// Initialization counter value 42
counter = 42;
print('initState called');
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('ResearchThinker initState Example'),
),
body: Center(
//Counter value will be 42 because we mentioned 42 inside init State
child: Text('Counter: $counter',style: TextStyle(fontSize:35,fontWeight:FontWeight.bold,
color: Colors.black),),
),
);
}
}