title: How to add a TextField to UIAlertView in Swift
body: <p>I have this code, but I dont know how to show a textfield inside the UIAlertView.</p>
  
  <pre><code>var altMessage = UIAlertController(title: "Warning", message: "This is Alert Message", preferredStyle: UIAlertControllerStyle.Alert)
  altMessage.addAction(UIAlertAction(title: "Done", style: UIAlertActionStyle.Default, handler: nil))
  self.presentViewController(altMessage, animated: true, completion: nil)
  </code></pre>
  
  <p>I have this code for textfield , how can I show this in UIAlerView   </p>
  
  <pre><code>var my:UITextField = UITextField(frame: CGRectMake(0, 0, 10, 10))
  </code></pre>
  
  <hr>
  
  <p>I also tried this code:</p>
  
  <pre><code>var alert = UIAlertView()
  alert.title = "Enter Input"
  alert.addButtonWithTitle("Done")
  alert.alertViewStyle = UIAlertViewStyle.PlainTextInput
  alert.addButtonWithTitle("Cancel")
  alert.show()
  </code></pre>
  
  <p>When I specify the AlertStyle plainText, it shows a TextField with default placeholder, "Login".. I want to change that, I want to show a Keyboard of Decimal Pad. I also want to handle the value the user enters into the textField. Can someone help me with this?</p>