颤动一次介绍屏幕？

  • Z时代
  • 2024-01-10
  • 分类：问答

我的应用程序有一个简介屏幕，但是每次打开应用程序时都会显示该屏幕， 屏幕 。

怎么做？

//THIS IS THE SCREEN COMES 1ST WHEN OPENING THE APP (SPLASHSCREEN)
class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => _SplashScreenState();
}
class _SplashScreenState extends State<SplashScreen> {
  @override
  void initState() {
    super.initState();
    //After 2seconds of time the Introscreen will e opened by bellow code
    Timer(Duration(seconds: 2), () => MyNavigator.goToIntroscreen(context));
  }
  //The below code has the text to show for the spalshing screen
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: new Center(
        child: Text('SPLASH SCREEN'),
      ),
    );
  }
}

每次此屏幕打开介绍屏幕时，都会延迟2秒。但我第一次只想用sharedpreference??

请添加所需的代码。

回答：

如果您只想第一次显示介绍屏幕，则需要在本地保存该用户已经看过介绍的屏幕。

对于这种情况，您可以使用Shared

Preference。有一个用于共享首选项的Flutter软件包，您可以使用

：

：

import 'dart:async';
import 'package:after_layout/after_layout.dart';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      color: Colors.blue,
      home: new Splash(),
    );
  }
}
class Splash extends StatefulWidget {
  @override
  SplashState createState() => new SplashState();
}
class SplashState extends State<Splash> with AfterLayoutMixin<Splash> {
  Future checkFirstSeen() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    bool _seen = (prefs.getBool('seen') ?? false);
    if (_seen) {
      Navigator.of(context).pushReplacement(
          new MaterialPageRoute(builder: (context) => new Home()));
    } else {
      await prefs.setBool('seen', true);
      Navigator.of(context).pushReplacement(
          new MaterialPageRoute(builder: (context) => new IntroScreen()));
    }
  }
  @override
  void afterFirstLayout(BuildContext context) => checkFirstSeen();
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: new Center(
        child: new Text('Loading...'),
      ),
    );
  }
}
class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Hello'),
      ),
      body: new Center(
        child: new Text('This is the second page'),
      ),
    );
  }
}
class IntroScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('IntroScreen'),
      ),
      body: new Center(
        child: new Text('This is the IntroScreen'),
      ),
    );
  }
}

感谢BenB注意到错误地使用延迟initState。我用过a，delay因为有时上下文尚未立即准备就绪initState。

因此，现在我替换afterFirstLayout了上下文准备就绪的内容。您将需要安装after_layout软件包。

以上是 颤动一次介绍屏幕？ 的全部内容， 来源链接： utcz.com/qa/397726.html

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