swift - 验证UITextField

Question

我在我的应用程序中有这个插座:

@IBOutlet var name1: UITextField!

@IBOutlet var name2: UITextField!

@IBOutlet var name3: UITextField!

@IBOutlet var name4: UITextField!

@IBOutlet var newButton: UIButton!

我试图做的是以下内容:

每当用户在这四个文本字段之一中键入内容或删除某些内容时,我想检查是否有任何文本字段为空

如果任何文本字段为空,则应禁用该按钮.

如果设置了所有文本字段(非空),则应启用该按钮.

我的代码:

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

    setButton()

    return true
}

func setButton() {

    let inputValid = checkInput()

    if inputValid {

        newButton.enabled = true

    } else {

        newButton.enabled = false

    }

}

func checkInput() -> Bool {

    let name1Value = name1.text
    let name2Value = name2.text
    let name3Value = name3.text
    let name4Value = name4.text

    if !name1Value.isEmpty && !name2Value.isEmpty && !name3Value.isEmpty && !name4Value.isEmpty {

        return true

    }

    return false

}

好的,它现在可以使用50%.

当我在每个文本字段中键入一个字符时,该按钮仍处于禁用状态.

当我向任何文本字段添加第二个时,按钮被启用等...

有谁可以帮我这个？

问候和感谢!

Answer 1

或者,你可以使用它,每次按下一个键时都会调用它:

name1.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name2.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name3.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name4.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)


func textFieldDidChange(textField: UITextField) {
    if name1.text?.isEmpty || name2.text?.isEmpty || name3.text?.isEmpty || name4.text?.isEmpty {
        //Disable button
    } else {
        //Enable button
    }
}

Answer 2

Swift 4- 这是我为避免长时间使用条件而解决的方法-与接受的答案不同，这还允许您对每个文本字段进行实时验证，可以根据用户键入的内容更新UI。

let textfields : [UITextField] = [name1, name2, name3, name4]
for textfield in textfields {
  textfield.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)
}


@objc func textFieldDidChange(_ textField: UITextField) {
  //set Button to false whenever they begin editing
  yourButton.isEnabled = false
  guard let first = textFields[0].text, first != "" else {
        print("textField 1 is empty")
        return
    }
    guard let second = textFields[1].text, second != "" else {
        print("textField 2 is empty")
        return
    }
    guard let third = textFields[2].text, third != "" else {
        print("textField 3 is empty")
        return
    }
    guard let forth = textFields[3].text, forth != "" else {
        print("textField 4 is empty")
        return
    }
    // set button to true whenever all textfield criteria is met.
    yourButton.isEnabled = true

}