ios - How do I unable the "Space" Key on the keyboard in Swift? -

i'm creating login system , don't want spaces allowed in username field. instead of check , validating field, want prevent spaces being added.

so, every time user presses spacebar, nothing should happen. how can that? i've seen instagram this.

this code far:

import uikit  class viewcontroller: uiviewcontroller, uitextfielddelegate {      @iboutlet weak var signup: uibarbuttonitem!     @iboutlet weak var navbar: uinavigationbar!     @iboutlet weak var usernametext: uitextfield!       override func viewdidload() {         super.viewdidload()               self.navigationcontroller?.navigationbar.clipstobounds = true         usernametext.attributedplaceholder = nsattributedstring(string:"typeyourusername",             attributes:[nsforegroundcolorattributename: uicolor.whitecolor()])          func textfield(usernametext: uitextfield, shouldchangecharactersinrange range: nsrange, replacementstring string: string) -> bool {             if (string == " ") {                 return false             }             return true         }     }      override func didreceivememorywarning() {         super.didreceivememorywarning()         // dispose of resources can recreated.     }      override func viewwillappear(animated: bool) {         usernametext.becomefirstresponder()     }       override func prefersstatusbarhidden() -> bool {         return true     } } 

yes can it. override uitextfield delegate method shouldchangecharactersinrange. , in method check space character. if found return false.

note: don't forget set delegate textfield.

func textfield(textfield: uitextfield, shouldchangecharactersinrange range: nsrange, replacementstring string: string) -> bool {     if (string == " ") {         return false     }     return true } 

edit: more code

class viewcontroller : uiviewcontroller, uitextfielddelegate {      @iboutlet weak var textfield : uitextfield!      override func viewdidload() {         super.viewdidload()         textfield.delegate = self     }      func textfield(textfield: uitextfield, shouldchangecharactersinrange range: nsrange, replacementstring string: string) -> bool {         if (string == " ") {           return false         }         return true     } } 

here textfield object iboutlet. means text field control in storyboard , connected variable.