现在，我有以下解决方案。也许我忽略了一些使我能够直接访问“ swiftSharedInstance”的东西？

@objc class SingletonTest: NSObject {

    // swiftSharedInstance is not accessible from ObjC
    class var swiftSharedInstance: SingletonTest {
    struct Singleton {
        static let instance = SingletonTest()
        }
        return Singleton.instance
    }

    // the sharedInstance class method can be reached from ObjC
    class func sharedInstance() -> SingletonTest {
        return SingletonTest.swiftSharedInstance
    }

    // Some testing
    func testTheSingleton() -> String {
        return "Hello World"
    }

}

然后在ObjC中，我可以获取sharedInstance类方法（在导入xcode生成的swift标头绑定之后）

SingletonTest *aTest = [SingletonTest sharedInstance];
NSLog(@"Singleton says: %@", [aTest testTheSingleton]);