我是第一次开发扑动应用程序。.我在添加图像方面有问题。我有以下问题:

1. 在哪里创建图像文件夹？
2. 在 pubspec.ymal 中何处添加资产标记？
3. 是否需要任何资产文件夹？

我试过:

 assets:
- images/lake.jpg

Ymal:

完整档案:

name: my_flutter_app
description: A new Flutter application.


dependencies:
flutter:
sdk: flutter


cupertino_icons: ^0.1.2


dev_dependencies:
flutter_test:
sdk: flutter


flutter:
uses-material-design: true,
assets:
- images/lake.jpg

错误日志:

#/properties/flutter/properties/uses-material-design: type: wanted [boolean] got true,
Error detected in pubspec.yaml:
Error building assets


FAILURE: Build failed with an exception.


* Where:
Script '/home/abc/Downloads/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 435


* What went wrong:
Execution failed for task ':app:flutterBuildDebug'.
> Process 'command '/home/abc/Downloads/flutter/bin/flutter'' finished with non-zero exit value 1


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.


* Get more help at https://help.gradle.org


BUILD FAILED in 1s
Finished with error: Gradle build failed: 1

我的主要代码是:

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.


import 'package:flutter/material.dart';
// Uncomment lines 7 and 10 to view the visual layout at runtime.
//import 'package:flutter/rendering.dart' show debugPaintSizeEnabled;


void main() {
//debugPaintSizeEnabled = true;
runApp(new MyApp());
}


class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
Widget titleSection = new Container(
padding: const EdgeInsets.all(32.0),
child: new Row(
children: [
new Expanded(
child: new Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
new Container(
padding: const EdgeInsets.only(bottom: 8.0),
child: new Text(
'Oeschinen Lake Campground',
style: new TextStyle(
fontWeight: FontWeight.bold,
),
),
),
new Text(
'Kandersteg, Switzerland',
style: new TextStyle(
color: Colors.grey[500],
),
),
],
),
),
new Icon(
Icons.star,
color: Colors.red[500],
),
new Text('41'),
],
),
);


Column buildButtonColumn(IconData icon, String label) {
Color color = Theme.of(context).primaryColor;


return new Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
new Icon(icon, color: color),
new Container(
margin: const EdgeInsets.only(top: 8.0),
child: new Text(
label,
style: new TextStyle(
fontSize: 12.0,
fontWeight: FontWeight.w400,
color: color,
),
),
),
],
);
}


Widget buttonSection = new Container(
child: new Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
buildButtonColumn(Icons.call, 'CALL'),
buildButtonColumn(Icons.near_me, 'ROUTE'),
buildButtonColumn(Icons.share, 'SHARE'),
],
),
);


Widget textSection = new Container(
padding: const EdgeInsets.all(32.0),
child: new Text(
'''
Lake Oeschinen lies at the foot of the Blüemlisalp in the Bernese Alps. Situated 1,578 meters above sea level, it is one of the larger Alpine Lakes. A gondola ride from Kandersteg, followed by a half-hour walk through pastures and pine forest, leads you to the lake, which warms to 20 degrees Celsius in the summer. Activities enjoyed here include rowing, and riding the summer toboggan run.
''',
softWrap: true,
),
);


return new MaterialApp(
title: 'Flutter Demo',
home: new Scaffold(
appBar: new AppBar(
title: new Text('Top Lakes'),
),
body: new ListView(
children: [
new Image.asset(
'images/lake.jpg',
width: 600.0,
height: 240.0,
fit: BoxFit.cover,
),
titleSection,
buttonSection,
textSection,
],
),
),
);
}
}

我指的是这个教程 翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳翻译: 奇芳 https://flutter.io/tutorials/layout/

我还想问，是否有任何工具，清洁重建在颤动，因为我找不到任何选择这一点。.

如果你能帮忙，我将不胜感激。

谢谢！