一 创建Flutter应用
如果使用Android Studio 或者Visual Studio Code 可以从IDE中创建一个新Flutter应用程序，以AS为例，这里可以创建四种类型的项目。
当然也可以使用Flutter命令从命令行创建，通过help命令可以看有那些参数， 一般按下面命令就可以创建一个新的flutter项目
flutter create --help
➜flutter create --org com.cc.flutter.hello flutter_hello
Creating project flutter_hello...
Running "flutter packages get" in flutter_hello... 10.9s
Wrote 67 files.
All done!
Run "flutter doctor" for information about installing additional components.
In order to run your application, type:
cd flutter_hello flutter run
Your application code is in flutter_hello/lib/main.dart.