在Swift中按回车键切换文本字段

Question

我正在设计一个iOS应用程序,我希望在我的iPhone中按下返回键时,它会将我引导到下一个文本字段.

我发现了几个类似的问题,并且有很好的答案,但它们恰好都在Objective-C中,我正在寻找Swift代码,现在这就是我现在所拥有的:

func textFieldShouldReturn(emaillabel: UITextField) -> Bool{
    return true
}

它被放置在连接的文件和包含文本字段的UIView的控制器中,但我不确定这是不是正确的地方.

我基本上是新手,所以解释每一个小步骤,否则我会设法弄乱它.此外,我正在使用最新版本的Xcode,如果这有任何区别.

好的,所以我试了这个并得到了这个错误:
//could not find an overload for '!=' that accepts the supplied arguments

func textFieldShouldReturn(textField: UITextField) -> Bool {
    let nextTag: NSInteger = textField.tag + 1
    // Try to find next responder
    let nextResponder: UIResponder = textField.superview!.viewWithTag(nextTag)!
    if (nextResponder != nil) {
        // could not find an overload for '!=' that accepts the supplied arguments

        // Found next responder, so set it.
        nextResponder.becomeFirstResponder()
    } else {
        // Not found, so remove keyboard.
        textField.resignFirstResponder()
    }
    return false // We do not want UITextField to insert line-breaks.
}

在此先感谢好朋友!!

Answer 1

Swift 3.0(检查以前版本的编辑历史记录):

class ViewController: UIViewController,UITextFieldDelegate {
   // Link each UITextField (Not necessary if delegate and tag are set in Interface Builder)
   @IBOutlet weak var someTextField: UITextField!

   override func viewDidLoad() {
      super.viewDidLoad()
      // Do the next two lines for each UITextField here or in the Interface Builder
      someTextField.delegate = self
      someTextField.tag = 0 //Increment accordingly
   }

   func textFieldShouldReturn(_ textField: UITextField) -> Bool {
      // Try to find next responder
      if let nextField = textField.superview?.viewWithTag(textField.tag + 1) as? UITextField {
         nextField.becomeFirstResponder()
      } else {
         // Not found, so remove keyboard.
         textField.resignFirstResponder()
      }
      // Do not add a line break
      return false
   }
}

确保您的UITextField代理已设置且标记正确递增.这也可以通过Interface Builder完成.

这是我发现的Obj-C帖子的链接:如何浏览文本字段(下一个/完成按钮)

Answer 2

斯威夫特4

您可以轻松切换到另一个TextField.

• 在ViewController中添加UITextFieldDelegate和添加textFieldShouldReturn(_:)方法
• 在Interface Builder中从TextField拖动到ViewController.然后选择属性.注意:对所有TextField执行此操作delegate

• IBOutlet为所有TextField创建一个

  class ViewController: UIViewController, UITextFieldDelegate {
  
    @IBOutlet weak var txtFieldName: UITextField!
    @IBOutlet weak var txtFieldEmail: UITextField!
    @IBOutlet weak var txtFieldPassword: UITextField!
  
    override func viewDidLoad() {
      super.viewDidLoad()
  
    }
  
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
      if textField == txtFieldName {
         textField.resignFirstResponder()
         txtFieldEmail.becomeFirstResponder()
      } else if textField == txtFieldEmail {
         textField.resignFirstResponder()
         txtFieldPassword.becomeFirstResponder()
      } else if textField == txtFieldPassword {
         textField.resignFirstResponder()
      }
     return true
    }
  }
  

Answer 3

我建议你应该使用switch语句textFieldShouldReturn(_:).

// MARK: UITextFieldDelegate

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    switch textField {
    case nameTextField:
        phoneTextField.becomeFirstResponder()
    case phoneTextField:
        emailTextField.becomeFirstResponder()
    case emailTextField:
        descriptionTextField.becomeFirstResponder()
    default:
        textField.resignFirstResponder()
    }
    return false
}

Answer 4

这种方法需要在表视图和集合视图中进行一些更改,但我认为它对于简单的表单是可以的.

将您连接textFields到一个IBOutletCollection,按y坐标对其进行排序,然后textFieldShouldReturn(_:)跳转到下一个文本字段,直到结束:

@IBOutlet var textFields: [UITextField]!

...

textFields.sortInPlace { $0.frame.origin.y < $1.frame.origin.y }

...

func textFieldShouldReturn(textField: UITextField) -> Bool {
    if let currentIndex = textFields.indexOf(textField) where currentIndex < textFields.count-1 {
        textFields[currentIndex+1].becomeFirstResponder()
    } else {
        textField.resignFirstResponder()
    }
    return true
}    

或者只看示例项目(xcode 7 beta 4)

Answer 5

快速且以编程方式

class MyViewController: UIViewController, UITextFieldDelegate {

    let textFieldA = UITextField()
    let textFieldB = UITextField()
    let textFieldC = UITextField()
    let textFieldD = UITextField()

    var textFields: [UITextField] {
        return [textFieldA, textFieldB, textFieldC, textFieldD]
    }

    override func viewDidLoad() {
        // layout textfields somewhere 
        // then set delegate
        textFields.forEach { $0.delegate = self }
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if let selectedTextFieldIndex = textFields.firstIndex(of: textField), selectedTextFieldIndex < textFields.count - 1 {
            textFields[selectedTextFieldIndex + 1].becomeFirstResponder()
        } else {
            textField.resignFirstResponder() // last textfield, dismiss keyboard directly
        }
        return true
    }
}

Answer 6

Caleb 的Swift 4.0版本

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    if let nextField = self.view.viewWithTag(textField.tag + 1) as? UITextField {
        nextField.becomeFirstResponder()
    } else {
        textField.resignFirstResponder()
    }
    return false
}

PStextField.superview?不适合我