Explore Widget Lifecycle In Flutter

Flutter is a mobile framework that helps to modernize both iOS and Android app from a single codebase. It is a combination of stateful and stateless widgets. Like all frameworks, Flutter also has a lifecycle associated with all the apps that our Flutter app uses. is managed by lifecycle In this article, we will take a look at different types of apps available in the flutter app, lifecycle.

In this article, we will explore the Widget Lifecycle in Flutter. We will also implement a Widget Lifecycle demo, describe its properties, and use them in your flutter applications. So let’s get started.

Table of Contents :

Flutter

Widget Lifecycle

Widget Lifecycle Method

Code Implementation

Code File

Conclusion

Flutter :

“ Flutter is Google’s UI toolkit that helps you build beautiful and natively combined applications for mobile, web, and desktop in a single codebase in record time, Flutter offers great developer tools, with amazing hot reload”

Widget Lifecycle :

Everything in Flutter is a Widget, so before knowing about Lifecycle, we should know about Widgets in Flutter.

There are two types of widgets in Flutter.

• Stateless Widgets.
• Stateful Widgets.

Before knowing about the Lifecycle, we need to understand the difference between the two widgets.

=> Stateless Widgets: Stateless Widgets in Flutter are those widgets whose state once created cannot be changed, it becomes immutable like on variables, buttons, icons, etc., or any state that cannot be changed on the app to retrieve data. Returns a widget by overwriting the build method. We use it when the UI relies on the information inside the object itself.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

=> Stateful Widget: A Stateful widget maintains data and responds to whatever the data does inside the application. It is a mutable widget, so it is drawn multiple times in its lifetime.

We use this when the user dynamically updates the application screen. This is the most important of all the widgets, as it has a state widget, everyone knows that something has been updated on our screen.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

The life cycle of the StatefulWidget Diagram.

=> A stateful widget has the following lifecycle stages:

Widget Lifecycle Methods:

The life cycle is based on the state and how it changes. A stateful widget has a state so we can explain the life cycle of flutter based on it. Stage of the life cycle:

createState

initState()

didChangeDependencies()

build()

didUpdateWidget()

setState()

deactivate()

dispose()

• > initState(): Flutter’s initState() method is the first method that is used while creating a stateful class, here we can initialize variables, data, properties, etc. for any widget.

int a;
@override
void initState() {
  a= 0;
  super.initState();
}

Note: You can read the full blog here.