Persistent Swift Compiler Error: 'Value of type 'ObjectiveCClass' has no member 'method' in Flutter iOS App with Azure Speech SDK

Question

I am developing a Flutter application and integrating the Azure Speech SDK for keyword recognition on iOS. I'm working with a mixed Swift/Objective-C codebase and am consistently encountering a Swift compiler error, despite extensive troubleshooting.

The Core Problem:

My Swift AppDelegate.swift class cannot access a method (setFlutterChannel) that is explicitly declared and implemented in my custom Objective-C class (KeywordRecognizer). So basically, the app will recognize the keyword/wake word, but then it doesn't trigger the next action I guess because it's not bridging correctly to the swift code.

The Specific Error Message (consistently):

Swift Compiler Error (Xcode): Value of type 'KeywordRecognizer' has no member 'setFlutterChannel'

/Users/kimberlycoston/ShelfSenseSolo/ios/Runner/AppDelegate.swift:20:27

(Note: The exact line number might vary slightly based on file edits, but it always points to the call keywordRecognizer?.setFlutterChannel(keywordChannel)).

My Setup:

• iOS Native Code: (files linked here: https://drive.google.com/drive/folders/1jiBiHnrDFqn6gg6WOpXaf0BneUZL9eNd?usp=sharing)
  • __KeywordRecognizer.h__ (Objective-C header): Declares setFlutterChannel:(FlutterMethodChannel *)channel; and @property (strong, nonatomic, nullable) FlutterMethodChannel *flutterChannel;. It imports Foundation.h, SPXSpeechApi.h, and Flutter.h.
  • __KeywordRecognizer.m__ (Objective-C implementation): Implements setFlutterChannel: and uses self.flutterChannel for callbacks (e.g., [strongSelf.flutterChannel invokeMethod:@"onWakeWordDetected" arguments:nil];).
  • __Runner-Bridging-Header.h__: Imports GeneratedPluginRegistrant.h, SPXSpeechApi.h, KeywordRecognizer.h, and Flutter.h.
  • __AppDelegate.swift__: Instantiates KeywordRecognizer and attempts to call setFlutterChannel on it. It uses @objc class AppDelegate: FlutterAppDelegate.
• Azure Speech SDK Integration:
  • The MicrosoftCognitiveServicesSpeech.xcframework (the iOS embedded binary) is manually added to the Xcode project's "Frameworks, Libraries, and Embedded Content" section, with "Embed & Sign" selected.
  • The Podfile has been cleared of any MicrosoftCognitiveServicesSpeech-iOS or MicrosoftCognitiveServicesSpeechEmbedded-iOS entries to prevent conflicts. pod install has been run after Podfile changes.

Troubleshooting Steps Taken (without success, leading to this forum post):

1.  Confirmed method declaration/implementation: Verified setFlutterChannel is correctly in KeywordRecognizer.h and implemented in KeywordRecognizer.m.

2.  Bridging Header: Confirmed Runner-Bridging-Header.h explicitly imports KeywordRecognizer.h.

3.  Xcode Build Settings:

• "Objective-C Bridging Header" is set correctly to Runner/Runner-Bridging-Header.h for all build configurations.
• "Defines Module" is set to "Yes" for the Runner target.
• "Product Module Name" is consistent across all build configurations (Runner).

4.  File Inclusion/Compilation:

• KeywordRecognizer.m is explicitly listed and enabled in "Build Phases" -> "Compile Sources" for the Runner target.
• AppDelegate.swift is also in "Compile Sources".

5.  Clean Builds: Performed numerous "Product > Clean Build Folder" operations and manually deleted Xcode's Derived Data (~/Library/Developer/Xcode/DerivedData).

6.  Framework Management: Ensured the Azure SDK .xcframework is the only method of integration for the Speech SDK (no lingering CocoaPods entries).

7.  File Re-adding: As a last resort, removed KeywordRecognizer.h and KeywordRecognizer.m from the Xcode project (removed reference), cleaned Derived Data, and then re-added them.

Despite all these extensive efforts, the Swift compiler consistently reports that KeywordRecognizer has no setFlutterChannel member. It's as if the Swift compiler cannot properly resolve the Objective-C class's full interface from the bridging header.

ANY guidance or suggestions would be greatly appreciated!! Thank you!

Answer 1

Hello Kimberly !

Thank you for posting on Microsoft Learn.

Swift sees your class as a generic @objc type or only sees the interface declared in a module map but not the specific method.

The KeywordRecognizer.h uses @interface KeywordRecognizer : NSObject if it's declared like this, you're good.

If you're using a @class forward declaration for KeywordRecognizer somewhere instead of an import, Swift won't know the full class layout.

Remove @import KeywordRecognizer or any use of a compiled module that doesn’t expose the full interface.

If your project accidentally compiled KeywordRecognizer into a static library or dynamic framework, Swift will see only what’s in the module map usually not your custom methods like setFlutterChannel.

Go to your Xcode project > Build Settings (for Runner target), and verify the following:

Objective-C Bridging Header: Runner/Runner-Bridging-Header.h

Defines Module: YES

Always Embed Swift Standard Libraries: YES

Also, check that KeywordRecognizer.h is explicitly listed in your bridging header.