为颤振更新省道 - 开卷题库

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最佳答案

It might be due to the fact you are on channel stable which is the most secure builds of the four channels to get updated (channels are listed here)

If you are a bit more curious to try out the new features without having to risk bad builds I advocate channel beta:

Every month, we pick the "best" dev build of the previous month or so, and promote it to beta. These builds have been tested with our codelabs.

where the stable channel has this description:

When we believe we have a particularly good build, we promote it to the stable channel. We intend to do this more or less every quarter, but this may vary. We recommend that you use this channel for all production app releases. We may ship hotfixes to the stable channel for high-priority bugs, although our intent is to do this rarely.

You can change the channel to point at beta by running this command in your terminal: flutter channel beta followed by flutter upgrade to ensure you have got the last release for this particular branch.

Let me know how this affect your situation.

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follow some command given below :

1.flutter version -> give all the flutter version list available.

2.flutter version v1.12.13+hotfix.7 -> you can switch to any given flutter version
in your console by 1st command.

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You have to upgrade flutter from cli with flutter upgrade command. Then flutter will use latest version of Dart SDK. Flutter does not use your local Dart Sdk.

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If using windows, you can use chocolatey to upgrade sdk by using command.

choco upgrade dart-sdk

If you want the latest pre-release version:

choco upgrade dart-sdk --pre

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I have two version of flutter SDK at the same time for two different flutter projects. I had changed the current SDK to 1.12 so it was complaining about dart SDK version. I changed the current version to 1.20 and the problem solved.

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This issue is because of the dart version and by updating flutter the dart version won't update, the way for solving this is, first, you need to be on the dev or master channel,

flutter channel master
flutter upgrade

after that run flutter doctor -v as you see your dart is still an old one

in this step, you should update it manually, as the doc says Dart

for Windows user

choco upgrade dart-sdk

for Mac users if you user brew to install dart

brew upgrade dart

and if you don't, you can install it

 brew tap dart-lang/dart
brew install dart

wish this solves your issue.

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Yeah, the cause of the problem is inherent in the fact that Flutter does not use the dart present on your Local machine the Flutter sdk instead comes with the latest compatible dart sdk shipped along with it.

When you run the command flutter version it prints the current flutter version and the current dart-sdk version shipped along with it. If you wish to use a later version of the dart sdk you'll have to upgrade your flutter sdk and if the specific dart-sdk version you want is not yet available for any branch in the stable channel I will suggest you switch to the master or dev channel and hopefully the latest release of those channels will support the required sdk constraint you need. But beware other branches aside the stable branch are not totally safe as you can encounter strange and unresolved errors so have that at the back of your mind.

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Open terminal commands to Upgrade Flutter – Dart SDK
1-> C:\flutter
2->run command  " flutter channel master "
3->run command after switching " flutter upgrade "

Now open android studio which automatically fetch updated sdk from flutter folder

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You can upgrade dart SDK using terminal by typing flutter upgrade. This will upgrade both flutter and dart SDK. Actually flutter upgrade includes the Flutter and Dart SDK and doesn't install them separately.

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If you struggle to make any of these solutions work, you might have different versions of flutter on your system.

I checked my version on the command line and upgraded via 'flutter upgrade' to the latest stable release, which did not solve the problem in IntelliJ / Android Studio, as that pointed to another local version of flutter.

To check, run 'which flutter' on the command line and check with the version displayed in "Preferences --> Languages & Frameworks --> Flutter" and make sure they point at the same flutter installation.

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if you using android studio, Tools->Flutter->Flutter upgrade click on flutter upgrade then you can install it

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Try this

flutter channel stable
flutter upgrade

or this

flutter channel master
flutter upgrade

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I'm using flutter upgrade channel stable on macOS and it's working fine

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The dark SDK that you updated is probably the one on your global dart installation.

Check your flutter dart path with the command

which flutter dart

If it is looking like this

[/path-to-flutter-sdk]/bin/flutter
/usr/local/bin/dart

you need to change it to use the one associated to flutter:

[/path-to-flutter-sdk]/bin/flutter
[/path-to-flutter-sdk]/bin/dart

To update it, you need to update your $PATH so [/path-to-flutter-sdk]/bin/flutter comes before /usr/local/bin.

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You might need to Update your pubspec.yaml depending on the flutter channel you want to work on:

If you are on stable channel :

Go into pubspec.yaml and type in:

environment:
sdk: ">=2.2.0 <3.0.0"

(Whatever Dart SDK version you want comes in the front)

dependencies:
cupertino_icons: ^1.0.0

If you are on beta channel :

environment:
sdk: ">=2.12.0 <3.0.0"


dependencies:
cupertino_icons: ^1.0.1

Then if you are on stable channel (or beta), open the terminal in your IDE and enter

flutter channel stable
# or flutter channel beta
flutter upgrade
flutter pub get

Check the version with flutter --version

Hope it helps.

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it is so simple if dart was installed with flutter just do the below line:

flutter upgrade