swift3.0键盘弹起遮挡输入框问题的解决方案

extension LoginViewController:UITextFieldDelegate
{
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
//键盘收回，view放下
UIView.animate(withDuration: 0.4, animations: {
self.view.frame.origin.y = 0
})
return true
}
func textFieldDidBeginEditing(_ textView:UITextField) {
//view弹起跟随键盘，高可根据自己定义
UIView.animate(withDuration: 0.4, animations: {
self.view.frame.origin.y = -150
})
}
}