title: How to Get Rid of Objective-C In Swift
body: <p>I'm having problems trying to get rid of Objective-C reference in my Swift code. Specifically, if I set the Swift 3 @objc Inference to Default, I get the following runtime error:</p>
  <pre><code>Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Receiving.TaskViewController numberOfComponentsInPickerView:]: unrecognized selector sent to instance 
  </code></pre>
  <p>My code is simple at that point. It is:</p>
  <pre><code>func numberOfComponentsInPickerView(_ pickerView: UIPickerView) -&gt; Int {
      return 1
  }
  </code></pre>
  <p>I'm not sure how to modify my code to stop this error. Or is there some other configuration step I need to do?</p>
  <p>Another issue I'm having is with selectors. If I use #selector(method), I have to put @objc in front of the method. What syntax should be used for a selector parameter so the method doesn't have to be exposed to Objective-C?</p>