Adding a splash screen to Flutter apps

2019-01-08 07:33发布

How would you approach adding a splash screen to Flutter apps? It should load and display before any other content. Currently there is a brief flash of color before the Scaffold(home:X) widget loads.

标签: flutter
10条回答
你好瞎i
2楼-- · 2019-01-08 08:12

If you flutter created your project, you can follow the steps at https://flutter.io/assets-and-images/#updating-the-launch-screen.

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放荡不羁爱自由
3楼-- · 2019-01-08 08:12

Adding a page like below and routing might help

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutkart/utils/flutkart.dart';
import 'package:flutkart/utils/my_navigator.dart';

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

class _SplashScreenState extends State<SplashScreen> {
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    Timer(Duration(seconds: 5), () => MyNavigator.goToIntro(context));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        fit: StackFit.expand,
        children: <Widget>[
          Container(
            decoration: BoxDecoration(color: Colors.redAccent),
          ),
          Column(
            mainAxisAlignment: MainAxisAlignment.start,
            children: <Widget>[
              Expanded(
                flex: 2,
                child: Container(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      CircleAvatar(
                        backgroundColor: Colors.white,
                        radius: 50.0,
                        child: Icon(
                          Icons.shopping_cart,
                          color: Colors.greenAccent,
                          size: 50.0,
                        ),
                      ),
                      Padding(
                        padding: EdgeInsets.only(top: 10.0),
                      ),
                      Text(
                        Flutkart.name,
                        style: TextStyle(
                            color: Colors.white,
                            fontWeight: FontWeight.bold,
                            fontSize: 24.0),
                      )
                    ],
                  ),
                ),
              ),
              Expanded(
                flex: 1,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    CircularProgressIndicator(),
                    Padding(
                      padding: EdgeInsets.only(top: 20.0),
                    ),
                    Text(
                      Flutkart.store,
                      softWrap: true,
                      textAlign: TextAlign.center,
                      style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 18.0,
                          color: Colors.white),
                    )
                  ],
                ),
              )
            ],
          )
        ],
      ),
    );
  }
}

If you want to follow through, see: https://www.youtube.com/watch?v=FNBuo-7zg2Q

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不美不萌又怎样
4楼-- · 2019-01-08 08:13

Multiple ways you could do this, but the easiest one which I use is:

For Launch Icons I use the flutter library Flutter Launcher Icon

For the Custom Splash Screen I create different Screen resolutions and then add the splash images in the mipmap folder as per the resolution for Android.

The last part is adjusting the launch_background.xml in the drawable folder in res folder in Android.

Just change your code to look like below:

<?xml version="1.0" encoding="utf-8"?>
<!-- Modify this file to customize your launch splash screen -->
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- <item android:drawable="@android:color/white" />
    <item android:drawable="@drawable/<splashfilename>" />     --> -->

    <!-- You can insert your own image assets here -->
    <item>
        <bitmap
            android:gravity="center"
            android:src="@mipmap/<Your splash image name here as per the mipmap folder>"/>
    </item>
</layer-list>

Few devs I have seen add the splash as drawable, I tried this but somehow the build fails in Flutter 1.0.0 and Dart SDK 2.0+. Therefore I prefer to add the splash in bitmap section.

iOS Splash-screen creation is rather simpler.

In the Runner folder in iOS just update the LaunchImage.png files with your custom Splash screen images with same names as LaunchImage.png @2x, @3x, @4x.

Just an addition I feel its good to have a 4x image as well in the LaunchImage.imageset. Just update your code in Content.json with following lines, below 3x scale to add a 4x scale option:

{
      "idiom" : "universal",
      "filename" : "LaunchImage@4x.png",
      "scale" : "4x"
    }
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在下西门庆
5楼-- · 2019-01-08 08:14

Both @Collin Jackson and @Sniper are right. You can follow these steps to set up launch images in android and iOS respectively. Then in your MyApp(), in your initState(), you can use Future.delayed to set up a timer or call any api. Until the response is returned from the Future, your launch icons will be shown and then as the response come, you can move to the screen you want to go to after the splash screen. You can see this link : Flutter Splash Screen

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▲ chillily
6楼-- · 2019-01-08 08:19

persons who are getting the error like image not found after applying the verified answer make sure that you are adding @mipmap/ic_launcher instead of @mipmap/ ic_launcher.png

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Summer. ? 凉城
7楼-- · 2019-01-08 08:22

The code from Jaldhi Bhatt doesn't works for me.

Flutter throws a 'Navigator operation requested with a context that does not include a Navigator.'

I fixed the code wrapping the Navigator consumer component inside of another component that initialize the Navigator context using routes, as mentioned in this article.

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:my-app/view/main-view.dart';

class SplashView extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
        home: Builder(
          builder: (context) => new _SplashContent(),
        ),
        routes: <String, WidgetBuilder>{
          '/main': (BuildContext context) => new MainView()}
    );
  }
}

class _SplashContent extends StatefulWidget{

  @override
  _SplashContentState createState() => new _SplashContentState();
}

class _SplashContentState extends State<_SplashContent>
    with SingleTickerProviderStateMixin {

  var _iconAnimationController;
  var _iconAnimation;

  startTimeout() async {
    var duration = const Duration(seconds: 3);
    return new Timer(duration, handleTimeout);
  }

  void handleTimeout() {
    Navigator.pushReplacementNamed(context, "/main");
  }

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

    _iconAnimationController = new AnimationController(
        vsync: this, duration: new Duration(milliseconds: 2000));

    _iconAnimation = new CurvedAnimation(
        parent: _iconAnimationController, curve: Curves.easeIn);
    _iconAnimation.addListener(() => this.setState(() {}));

    _iconAnimationController.forward();

    startTimeout();
  }

  @override
  Widget build(BuildContext context) {
    return new Center(
        child: new Image(
          image: new AssetImage("images/logo.png"),
          width: _iconAnimation.value * 100,
          height: _iconAnimation.value * 100,
        )
    );
  }
}
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