iOS - Can't access Swift Singleton from Objective-C - ios

Question

I can't access my Swift Singleton Class from my Objective-C ViewController.
Xcode does recognize my Swift Class, it builds, so I don't think it is a bridging header issue.
Here is my Swift Singleton Class :
#objc class MySingleton : NSObject {
static let shared = MySingleton()
private override init() {}
}
And then in my .m file I import this header :
#import "myProject-Swift.h"
And use the Singleton this way :
MySingleton *testSingleton = [MySingleton shared];
or this way :
[MySingleton shared];
It does recognize the MySingleton class type, but I can't access any functions or properties of this class.
What am I missing? All the similar posts didn't help.
EDIT: I made a test function
func testPrint() {
print("Singleton worked")
}
And called it this way in the objective-c file :
[[MySingleton shared] testPrint];
No known instance for selector 'testPrint'

Answer 1

In your Swift Singleton class, add #objc for the method testPrint() like:
#objc func testPrint() {
print("Singleton worked")
}
Now, you access the method from Objective-C class:
[[MySingleton shared] testPrint];

Answer 2

use #objc attribute before the testPrint() function. refer documentation
To be accessible and usable in Objective-C, a Swift class must be a descendant of an Objective-C class or it must be marked #objc.

Answer 3

You need to add #objc to any property or function you want to expose to Objective-C, including the static shared property:
class MySingleton : NSObject {
#objc static let shared = MySingleton()
private override init() { }
#objc func testPrint() { print("Singleton worked") }
}
Then, the call from Objective-C file:
MySingleton *singleton = [MySingleton shared];
[singleton testPrint];
Note that marking the whole class as #objc isn't a replacement for the above. It is actually not needed anymore, and it's enough to inherit from NSObject.