Trouble passing Swift 4 String to Obj-C++ -[_SwiftValue dataUsingEncoding:]: unrecognized selector sent to instance

Question

I have some Objective-C++ code like this:

// header

@interface MyObjcClass

- (void) myMethod: (NSString *) text;         


        

Answer 1

I'd try

func mySwiftFunc(text: String) {
     myObjcClassInstance.perform(#selector(NSSelectorFromString("myMethod:"), with: text as NSString)
}

If that won't work try:

func mySwiftFunc(text: String) {
    let selector : Selector = NSSelectorFromString("myMethod:")
    let methodIMP : IMP! = myObjcClassInstance.method(for: selector)
    unsafeBitCast(methodIMP,to:(@convention(c)(Any?,Selector,NSString)->Void).self)(myObjcClassInstance,selector,text as NSString)
}

Probably possible without selector name "myMethod:" String dependence, but I skipped the casting gymnastics as it's not the essence of the problem.