Question: I am trying to initialize a central manager instance to make an app with Bluetooth connectivity.

This is part of my code:

```
class ViewController: UIViewController, CBCentralManagerDelegate {
   var myCentralManager = CBCentralManager(delegate: self, queue: nil) //error on this line
   func centralManagerDidUpdateState(central: CBCentralManager!) { 
}

```

I get an error:

> 
> "Type 'ViewController -> () -> ViewController!' does not conform to protocol 'CBCentralManagerDelegate'
> 
> 
> 

The only method required by the protocol is `centralManagerDidUpdateState()` which I have added, so why do I get an error?

Answer: 
The error message is a little deceiving and is pointing you away from the actual issue. The problem is that you are accessing `self` in the initializer for a stored property, which you can't do like this.

One workaround is to simply declare the property without initializing it, and then move the assignment to the variable to somewhere like an initializer for your view controller, or one of your view controller's lifecycle methods, like viewDidLoad.
I actually found a tricky workaround, as long as you already found some other's open source project which uses CBCentralManagerDelegate. (And it is not hard to find some open source projects that use CBCentralManagerDelegate)

Lets say in the open source project, "ViewController.swift" uses CBCentralManagerDelegate. 
In your project, you need "TESTViewController.swift" to use CBCentralManagerDelegate.

Now all you need to do is to 

Step 1, Copy (that is, drag) the ViewController.swift (which is from the open source project) to your project

Step 2, delete all lines in the ViewController.swift, which was just dragged to your project.

Step 3, If needed, rename it from ViewController.swift to TESTViewController.swift, and rename the class name as well.

Step 4, Now you can write your own code
"class TESTViewController: UIViewController, CBCentralManagerDelegate {...} "

Yeah, this might be silly, but it does work for my project quickly.