title: Dismiss Keyboard when editing UItextfield on Swift
body: <p>i want to make a calculator with two textfield. there are numbers buttons and mathematical operations buttons. but i couldn't dismiss keyboard when clicking textfield. i never want to show keyboard but , want to edit textfield with numbers buttons.</p>
  
  <p>touchbegans or textFieldShoulBeginEditing method didn't worked for me.</p>