当我运行 flutter doctor 时，它显示了以下错误：
Running flutter doctor...
Doctor summary (to see all details, run flutter doctor -v):
[?] Flutter (Channel stable, v1.2.1, on Microsoft Windows [Version 10.0.17134.112], locale en-US)
[!] Android toolchain - develop for Android devices (Android SDK version 27.0.3)
X Flutter requires Android SDK 28 and the Android BuildTools 28.0.3
To update using sdkmanager, run:
D:/Tools/sdk\tools\bin\sdkmanager "platforms;android-28" "build-tools;28.0.3"
or visit https://flutter.io/setup/#android-setup for detailed instructions.
X Android license status unknown.
[?] Android Studio (version 3.3)
[!] IntelliJ IDEA Ultimate …