title: Custom inputView performing. Custom inputView doesn't appear unless default keyboard is opened
body: <p>I have a problem that I cannot perform custom inputView unless keyboard is opened. I have 2 UITextField one of them has custom inputView. Let's call them tf1 and tf2. tf2 has custom inputView. if I tap tf2 first nothing happening. If I tap tf1 first and default keyboard appears and then when I click tf2 custom inputView appears too. If there is no keyboard on the screen custom inputView doesn't appear. If there is a keyboard on the screen custom inputView can appear. Why?</p>
  
  <p>How I assign inputview is shown below :</p>
  
  <pre><code>let numPad = KeyboardViewController(nibName:"KeyboardView",bundle: NSBundle.mainBundle())
  let numPadFrame = CGRectMake(0, 0, 1024, 352)
  
  override func viewDidLoad() {
      super.viewDidLoad()
  
      customKeyboard = numPad.view
      customKeyboard.frame = numPadFrame
      tf2.inputView = customKeyboard
  </code></pre>