How to downgrade the dart version?

[xioxu]

I upgrade the dart version to 2.1 in my Windows Env, but it brokes my project, since one module 'audio-play' throws :
The current Dart SDK version is 2.1.0-dev.3.1.flutter-760a9690c2.
Because ***** depends on audioplayer any which requires SDK version >=1.8.0 <2.0.0, version solving failed.
I try to reinstall the flutter to a old version, and I can sure the dart-sdk is 2.0, but the flutter --version still outpus the dart version is 2.1.
So, I realy want to know how to make my project works, thanks in advance.

[zoechi]

You can't downgrade Dart independent of Flutter.
You can only downgrade Flutter to a version that contains the Dart version you desire.

You can also use dependency_overrides to overrule dependency constraints.
https://www.dartlang.org/tools/pub/dependencies#dependency-overrides

dependency_overrides:
  audioplayer: ^0.5.0

Ideally you'd report an issue with the package that claims not to be compatible with Dart 2.0 final
or even better create a pull request with a fix.

To revert to an older Flutter version you can use git to checkout a specific tag like 0.5.1

[github-actions]

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