你会如何在Flutter应用程序中添加启动画面?它应该在任何其他内容之前加载和显示。目前,在Scaffold(home:X)小部件加载之前,会有一个短暂的颜色闪烁。
当前回答
这是在Flutter中添加动态启动画面的最佳方法。
主要。飞镖
import 'package:flutter/material.dart';
import 'constant.dart';
void main() => runApp(MaterialApp(
title: 'GridView Demo',
home: SplashScreen(),
theme: ThemeData(
primarySwatch: Colors.red,
accentColor: Color(0xFF761322),
),
routes: <String, WidgetBuilder>{
SPLASH_SCREEN: (BuildContext context) => SplashScreen(),
HOME_SCREEN: (BuildContext context) => BasicTable(),
//GRID_ITEM_DETAILS_SCREEN: (BuildContext context) => GridItemDetails(),
},
));
SPLASHSCREEN。飞镖
import 'dart:async';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:app_example/constants.dart';
class SplashScreen extends StatefulWidget {
@override
SplashScreenState createState() => new SplashScreenState();
}
class SplashScreenState extends State<SplashScreen>
with SingleTickerProviderStateMixin {
var _visible = true;
AnimationController animationController;
Animation<double> animation;
startTime() async {
var _duration = new Duration(seconds: 3);
return new Timer(_duration, navigationPage);
}
void navigationPage() {
Navigator.of(context).pushReplacementNamed(HOME_SCREEN);
}
@override
dispose() {
animationController.dispose();
super.dispose();
}
@override
void initState() {
super.initState();
animationController = new AnimationController(
vsync: this,
duration: new Duration(seconds: 2),
);
animation =
new CurvedAnimation(parent: animationController, curve: Curves.easeOut);
animation.addListener(() => this.setState(() {}));
animationController.forward();
setState(() {
_visible = !_visible;
});
startTime();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
fit: StackFit.expand,
children: <Widget>[
new Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Padding(
padding: EdgeInsets.only(bottom: 30.0),
child: new Image.asset(
'assets/images/powered_by.png',
height: 25.0,
fit: BoxFit.scaleDown,
),
)
],
),
new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Image.asset(
'assets/images/logo.png',
width: animation.value * 250,
height: animation.value * 250,
),
],
),
],
),
);
}
}
常量。飞镖
String SPLASH_SCREEN='SPLASH_SCREEN';
String HOME_SCREEN='HOME_SCREEN';
主屏幕。飞镖
import 'package:flutter/material.dart';
class BasicTable extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("Table Widget")),
body: Center(child: Text("Table Widget")),
);
}
}
其他回答
添加如下所示的页面和路由可能会有所帮助
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),
)
],
),
)
],
)
],
),
);
}
}
如果你想坚持到底,请参见: https://www.youtube.com/watch?v=FNBuo-7zg2Q
Flutter为您提供了默认的启动画面的能力,但有很多插件可以做这项工作。如果你不想使用插件来完成任务,你担心添加一个新的插件可能会影响你的应用程序大小。然后你可以这样做。
为安卓
打开launch_background.xml,然后你可以放入启动画面图像,或者你想要的渐变颜色。这是用户打开应用程序时看到的第一件事。
为IOS
用Xcode打开你的应用,点击Runner > asset。xcassets > LaunchImage,你可以在这里添加图像。如果你想编辑启动屏幕图像的位置,你可以在LaunchScreen.storyboard上编辑。
SplashScreen(
seconds: 3,
navigateAfterSeconds: new MyApp(),
// title: new Text(
// 'Welcome In SplashScreen',
// style: new TextStyle(fontWeight: FontWeight.bold, fontSize: 20.0),
// ),
image: new Image.network('https://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Tesla_Motors.svg/1200px-Tesla_Motors.svg.png'),
backgroundColor: Colors.white,
styleTextUnderTheLoader: new TextStyle(),
photoSize: 150.0,
loaderColor: Colors.black),
),
);
@Collin Jackson和@Sniper都是对的。你可以按照以下步骤分别在android和iOS上设置启动映像。然后在你的MyApp()中,在你的initState()中,你可以使用Future.delayed来设置定时器或调用任何api。在Future返回响应之前,你的启动图标将会显示,然后随着响应的到来,你可以在启动画面后移动到你想要去的屏幕。您可以看到此链接:颤振启动画面
为安卓 App -> SRC -> main -> res ->drawble->launch_background.xml 和取消 注释块是这样的
<item>
<bitmap
android:gravity="center"
android:src="@mipmap/launch_image" /></item>
有人在这样编码后会出现错误吗 在android studio中使用与系统同步或使缓存无效并重置。这解决了我的问题 在颤振调试模式需要一些时间采取启动画面。构建后,它将减少像本机android