dart - How to check first time app launch in Flutter

Question

I am a beginner in a flutter, I have created my application but I want to check if the user opens the application for the first time after installing, I have seen this article but did not know how that?

This is the splash screen code, the code move the user directly to the Main screen after 3 sec, But I want to check if user first time opens the app and move the user to Welcome screen or if user not the first time and move the user to the Main screen.

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:book_pen/main.dart';
import 'package:book_pen/Welcome.dart';

void main() {
  runApp(new MaterialApp(
    home: new SplashScreen(),
    routes: <String, WidgetBuilder>{
      '/HomePage': (BuildContext context) => new HomePage(),
      '/WelcomePage': (BuildContext context) => new WelcomePage()
    },
  ));
}

class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => new _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen> {
  startTime() async {
    var _duration = new Duration(seconds: 3);

    return new Timer(_duration, navigationPageHome);
  }

  void navigationPageHome() {
    Navigator.of(context).pushReplacementNamed('/HomePage');
  }

  void navigationPageWel() {
    Navigator.of(context).pushReplacementNamed('/WelcomePage');
  }

  @override
  void initState() {
    super.initState();
    startTime();
  }

@override
  Widget build(BuildContext context) {
    Size size = MediaQuery.of(context).size;
    return Scaffold(
      body: Stack(
        children: <Widget>[
          Center(
            child: new Image.asset(
              'assets/images/SplashBack.jpg',
              width: size.width,
              height: size.height,
              fit: BoxFit.fill,
            ),
          ),
          Center(
              child: new Image.asset(
            'assets/images/BigPurppleSecSh.png',
            height: 150,
            width: 300,
          )),
        ],
      ),
    );
  }
}

Answer 1

@Abdullrahman, please use shared_preferences as suggested by others. Here is how you can do that,

• Depend on shared_preferences package in pubspec.yaml and run Packages get:

dependencies:
  flutter:
    sdk: flutter
  shared_preferences: ^0.5.4+6

• Import the package:

import 'package:shared_preferences/shared_preferences.dart';

• Implement it:

class _SplashScreenState extends State<SplashScreen> {
  startTime() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    bool firstTime = prefs.getBool('first_time');

    var _duration = new Duration(seconds: 3);

    if (firstTime != null && !firstTime) {// Not first time
      return new Timer(_duration, navigationPageHome);
    } else {// First time
      prefs.setBool('first_time', false);
      return new Timer(_duration, navigationPageWel);
    }
  }

  void navigationPageHome() {
    Navigator.of(context).pushReplacementNamed('/HomePage');
  }

  void navigationPageWel() {

    Navigator.of(context).pushReplacementNamed('/WelcomePage');
  }
  ........

Note: SharedPreferences data will be removed if user clears the cache. SharePreferences is a local option. If you want to prevent that, you can use firestore to save bool value but firestore would probably be an overkill for a simple task like this.

Hope this helps.