自从谷歌I/O2019发布Flutter web版本之后,有好多开发者尝试搭建环境,我也不例外,先前在公司电脑上搭建过一次,只是没有总结出教程,趁着周末在家无聊,再次在家里电脑搭建环境,由于官方文档中推荐是Visual Studio Code创建的项目,所以我就顺便研究了完全用命令行创建web项目。
本文在Mac环境下完成,windows环境大同小异,可作为参考。
官方英文文档:https://github.com/flutter/flutter_web
To use the Flutter SDK with the flutter_web preview make sure you have upgraded Flutter to at least v1.5.4 by running flutter upgrade from your machine. 在使用flutter_web预览版之前,要保证电脑中安装的Flutter版本是大于1.5.4。
以下是我机器的flutter doctor信息:
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.5.4-hotfix.2, on Mac OS X 10.14.5 18F132, locale zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[✓] iOS toolchain - develop for iOS devices (Xcode 10.2.1)
[✓] Android Studio (version 3.4)
[✓] VS Code (version 1.34.0)
[✓] Connected device (1 available)
• No issues found!
搭建步骤
1、从github上面把flutter_web项目克隆到本地
git clone https://github.com/flutter/flutter_web.git 存放目录随意,不过建议存放目录跟flutter sdk同级,日后更新维护好找
2、安装flutter_web的编译工具webdev
//环境变量只配置了flutter sdk而没有配置dart sdk
flutter pub global activate webdev
//环境变量已经配置了dart sdk
pub global activate webdev
安装过程可能出现如下信息,此为网友在windows上配置时出现的
Resolving dependencies…
It looks like pub.dartlang.org is having some trouble
Pub will wait for a while before trying to connect again.
Got socket error trying to find package webdev at https://pub.dartlang.org.
pub finished with exit code 69
此问题我没碰到过,如果出现上诉问题是因为网络问题,建议多尝试几次。
如果出现如下信息,则安装成功
Precompiling executables…
Precompiled webdev:webdev.
Installed executable webdev.
Activated webdev 2.0.6
上述信息中可能有一个Warning提示需要配置环境变量,按提示将$HOME/.pub-cache/bin配置到环境变量即可
可以尝试执行命令
//环境变量只配置了flutter sdk而没有配置dart sdk
flutter pub global run webdev
//环境变量已经配置了dart sdk
pub global run webdev
到此环境搭建成功了。
3、创建和启动项目
3.1使用现有项目
flutter_web目录下有examples几个demo项目,比如:hello_world
cd <flutter_web目录>/examples/hello_world
执行
flutter pub upgrade 或 pub upgrade
或
flutter pub get 或 pub get
如果出现
RandyWeideMacBook-Pro:hello_world wei$ flutter pub get
! flutter_web 0.0.0 from path ../../packages/flutter_web
! flutter_web_ui 0.0.0 from path ../../packages/flutter_web_ui
Running "flutter packages get" in hello_world... 21.9s
说明项目配置成功了,然后就是启动本地服务
//环境变量只配置了flutter sdk而没有配置dart sdk
flutter pub global run webdev serve
//环境变量已经配置了dart sdk
webdev serve
出现以下信息就是成功了
RandyWeideMacBook-Pro:hello_world wei$ flutter pub global run webdev serve
[INFO] Building new asset graph completed, took 1.5s
[INFO] Checking for unexpected pre-existing outputs. completed, took 1ms
[INFO] Serving `web` on http://localhost:8080
[INFO] Running build completed, took 18.3s
[INFO] Caching finalized dependency graph completed, took 201ms
[INFO] Succeeded after 18.5s with 556 outputs (3217 actions)
[INFO] ------------------------------------------------------------------------
然后就可以在浏览器使用信息中的地址 http://localhost:8080 访问到了。
3.2 创建新项目
官方给两种途径创建新项目 1)使用Visual Studio Code,具体配置Flutter Dart插件就不多说。使用命令面板Flutter: New Web Project,就可以创建一个新项目了,等配置完成后,按F5或者Debug -> Start Debugging,就可以启动服务并自动打开浏览器。
2)使用IntelliJ,没有研究
3)使用Android Studio,因为本身我是开发安卓的,习惯使用Studio进行开发。然而studio并不能创建一个普通的dart项目,或者flutter web项目,相信后期官方一定是能支持的。
目前想使用studio写代码的,可以使用Visual Studio Code,创建完项目完之后,再用Android Studio打开项目,也是可以的。
不过对于没有安装Visual Studio Code的同学来说的话,还可以用命令行来创建项目。
命令行创建web项目需要安装另一个工具
//环境变量只配置了flutter sdk而没有配置dart sdk
flutter pub global activate stagehand
//环境变量已经配置了dart sdk
pub global activate stagehand
跟安装webdev一样 安装成功后可以执行下面命令查看帮助
flutter pub global run stagehand
Stagehand will generate the given application type into the current directory.
usage: stagehand <generator-name>
--[no-]analytics Opt out of anonymous usage and crash reporting.
-h, --help Help!
--version Display the version for stagehand.
--author The author name to use for file headers.
(defaults to "<your name>")
Available generators:
console-full - A command-line application sample.
flutter-web-preview - A simple Flutter Web app.
package-simple - A starting point for Dart libraries or applications.
server-shelf - A web server built using the shelf package.
web-angular - A web app with material design components.
web-simple - A web app that uses only core Dart libraries.
web-stagexl - A starting point for 2D animation and games.
可以看到这个工具可以按照7种模版创建项目,我们使用的是flutter-web-preview,其他模版有兴趣的可以自行研究。
创建一个项目目录,然后
cd 目录
执行命令
//环境变量只配置了flutter sdk而没有配置dart sdk
flutter pub global run stagehand flutter-web-preview
//环境变量已经配置了dart sdk
stagehand flutter-web-preview
一个web项目就创建完成了,可以使用studio打开项目,使用flutter pub get
配置好完之后,可以进行正常的代码了。