Swift - 如何让textfield在仍然正确的答案输入正确的答案后仍识别空格

Question

我正在进行测验，其中存在文本字段并且用户输入答案。但是，我希望它能够识别出正确答案后的空格仍然正确。例如，如果答案是红色，并且用户在红色之后输入一个空格，它仍然被认为是正确的答案。以下是我的代码。请让我知道，并提前感谢您的所有帮助！

import Foundation 

import UIKit 

class Case1Q3ViewController: UIViewController, UITextFieldDelegate { 

    @IBOutlet weak var nextButton: UIButton! 
    @IBOutlet var questionLabel: UILabel! 

    @IBOutlet var correctAnswerLabel: UILabel! 

    @IBOutlet var inputTextField: UITextField! 

    var enteredAnswer: String? 

    var correctAnswer = "Well demarcated" 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     // Do any additional setup after loading the view. 
     NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(InputViewController1.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil) 
     NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(InputViewController1.keyboardWillHide), name: UIKeyboardWillHideNotification, object: nil) 

     inputTextField.delegate = self 

     titlesForLabels() 
     nextButton.enabled = false 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 

    func titlesForLabels() { 
     questionLabel.text = "Describe the borders" 
     correctAnswerLabel.text = correctAnswer 
     correctAnswerLabel.hidden = true 

     inputTextField.text = nil 
     inputTextField.enabled = true 
    } 

    func keyboardWillShow(notification: NSNotification) { 
     let userInfo = notification.userInfo! 

     let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue() 

     UIView.animateWithDuration(0.1, animations: {() -> Void in 
      self.view.frame.origin.y = -keyboardFrame.size.height 
     }) 
    } 

    func keyboardWillHide() { 
     UIView.animateWithDuration(0.1, animations: {() -> Void in 
      self.view.frame.origin.y = 0 
     }) 
    } 

    func textFieldShouldReturn(textField: UITextField) -> Bool { 
     textField.resignFirstResponder() 

     enteredAnswer = textField.text 

     checkForCorrectAnswer() 

     return true 
    } 

    func checkForCorrectAnswer() { 
     if enteredAnswer!.lowercaseString == correctAnswer.lowercaseString { 
      print("Correct") 
      correctAnswerLabel.textColor = UIColor.greenColor() 
      correctAnswerLabel.text = "Correct!" 
      nextButton.enabled = true 

     } else { 
      print("Wrong Answer") 
      correctAnswerLabel.textColor = UIColor.redColor() 
      correctAnswerLabel.text = "Incorrect! Please try again" 
      nextButton.enabled = false 

     } 
     correctAnswerLabel.hidden = false 
    } 
    override func viewWillAppear(animated: Bool) { 
     navigationItem.title = "Case 1 - Q3" 
    } 
} 

Answer 1

你应该检查面前人人平等修剪空白。您可以使用stringByTrimmingCharactersInSet:方法达到此目的。

func checkForCorrectAnswer() 
{ 
    let answer = enteredAnswer!.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet()) 
    if answer.lowercaseString == correctAnswer.lowercaseString 
    { 
     print("Correct") 
     correctAnswerLabel.textColor = UIColor.greenColor() 
     correctAnswerLabel.text = "Correct!" 
     nextButton.enabled = true 

    } 
    else 
    { 
     print("Wrong Answer") 
     correctAnswerLabel.textColor = UIColor.redColor() 
     correctAnswerLabel.text = "Incorrect! Please try again" 
     nextButton.enabled = false 

    } 
    correctAnswerLabel.hidden = false 
} 

Answer 2

你可以使用这样的事情：

let str = "Hi How Are You" 
let newString = str.stringByReplacingOccurrencesOfString(" ", withString: "") 
print(newString) //This prints "HiHowAreYou" 

然后，只需比较一下两者的用户不带空格回答正确的答案。在你的情况，你会使用这样的：

if enteredAnswer.stringByReplacingOccurrencesOfString(" ", withString: "").lowercaseString == correctAnswer.stringByReplacingOccurrencesOfString(" ", withString: "").lowercaseString { 
//Answer Is Correct 

}