title: How to add a button to the UITableView's footer view but preserve the last cell separator?
body: <p>I want to add a Plus button below the last table cell. It should look like this:</p>
  
  <p><a href="https://i.stack.imgur.com/nn2F3.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nn2F3.jpg" alt="enter image description here"></a></p>
  
  <p>To get this result I used this code:</p>
  
  <pre><code>let footerView = UIView()
  tableView.tableFooterView = footerView
  
  addButton.frame = CGRect(x: 0, y: 0, width: 45, height: 45)
  addButton.setTitle("+", for: [])
  addButton.titleLabel?.font = UIFont.systemFont(ofSize: 30)
  
  footerView.addSubview(addButton)
  
  addButton.addTarget(self, action: #selector(addSection), for: .touchUpInside)
  </code></pre>
  
  <p>It looks exactly how I want it but the problem is, as the footer view has a zero frame, the plus button inside it is unresponsive to touch events.</p>
  
  <p>If I set a frame to the footer view:</p>
  
  <pre><code>let footerView = UIView(frame: CGRect(x: 0, y: 0, width: 45, height: 45))
  </code></pre>
  
  <p>The button starts to respond to touches, but the last cell's separator line is gone:</p>
  
  <p><a href="https://i.stack.imgur.com/IJCdm.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IJCdm.jpg" alt="enter image description here"></a></p>
  
  <p>Is there a way to add some interactive content to the table footer view but preserve the last separator line?</p>