Flutter plugin development Unresolved reference: io

Question

Its my first attempt to create a flutter plugin, I created flutter plugin project from android studio and its running fine, when I tried to add platform specific code for android I stuck in some issues, in the same project platform specific code editing is almost dead (no linting). I imported MyPluginProject/android in android studio and there are also some issues,

Unresolved reference: io

Here is output of flutter doctor

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.7.8+hotfix.2, on Linux, locale en_US.UTF-8)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.0)
[✓] Android Studio (version 3.4)
[✓] Connected device (1 available)

• No issues found!

Answer 1

Solved the problem by following these steps from this issue on github.

1. Delete the .idea folder in the project (do not know if is needed but just to be sure)
2. In Android Studio click on Open an existing Android studio project and select the folder your_plugin/example/android (It's important to open your_plugin/example/android first and then your_plugin).

Answer 2

Shahzad Akram's answer didn't work for me but another tip from the given github link did:

Add the following to the module's build.gradle:

apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

after the other apply declarations, and

flutter {
    source '..'
}

at the bottom.

Edit: It looks like the extra lines need to be commented out for the depending project to build; definitely not ideal

Answer 3

In my case I had to:

1. Open the Flutter Project on Android Studio
2. Open the file located on android/src/main/kotlin/com/example/flutter_your_plugin/FlutterYourPlugin.kt
3. Android Studio will suggest you to Open for Editing in Android Studio

PS: My Android Studio Version: Android Studio Arctic Fox | 2020.3.1 Patch 3

Answer 4

In my case, it's happen because I have 2 Kotlin extension on VS code, you should remove one.