No known class method for selector 'swiftMethod:'

[naninunenoy]

Xcode: 10.2
Swift Language Version: 4

@objc attribute is required to call from obj-c source code in Swift4.
https://github.com/apple/swift-evolution/blob/master/proposals/0160-objc-inference.md
And Xcode 10.2 can only use Swift4 or later.

Please fix Exapmle.swift this way.

import Foundation

class Example : NSObject {
    static func callUnityMethod(_ message: String) {
        // Call a method on a specified GameObject.
        UnitySendMessage("CallbackTarget", "OnCallFromSwift", message)
    }
    
    // !!Here!!
    @objc static func swiftMethod(_ message: String) {
        print("\(#function) is called with message: \(message)")
        
        self.callUnityMethod("Hello, Unity!")
    }
}

[richardschembri]

@naninunenoy Fixed this issue on my fork, currently have a pending pull request.
https://github.com/richardschembri/unity-swift

[muyen]

@richardschembri, thank you fro the fix.