Question

我是swift语言的新手（3.0）。我正在开发一个适用于iOS的新应用程序。如何创建用户输入输入，按下按钮，然后在按钮下显示文本的文本框？谢谢！

Answer 1

您可以使用故事板或以编程方式执行此操作。这两个选项都适用于 Xcode 8 Swift 3

<强>故事板

将库中的UITextField，UIButton和UILabel拖到您的视图控制器上
为UITextField和UILabel ViewController.swift文件创建一个IBOutlet。
然后为同一UIButton文件创建ViewController.swift的IBAction。
将此代码写入按钮的动作功能中：

myLabel.text = myTextField.text

您的整个代码应如下所示：

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var myTextField: UITextField!

@IBOutlet weak var myLabel: UILabel!

@IBAction func myButtonPressed(_ sender: AnyObject) {

    myLabel.text = myTextField.text

}

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view, typically from a nib.

}
}

或以编程方式：

import UIKit

class ViewController: UIViewController {

// First create your components

let myTextField: UITextField = {
    let textField = UITextField()
    textField.backgroundColor = .lightGray //Just so you can see it
    textField.translatesAutoresizingMaskIntoConstraints = false
    return textField
}()

let myLabel: UILabel = {
    let label = UILabel()
    label.text = "Label text" //You may want to set this to something else to start with
    label.textAlignment = .center
    label.translatesAutoresizingMaskIntoConstraints = false
    return label
}()

let myButton: UIButton = {
    let button = UIButton()
    button.setTitle("Press me", for: .normal)
    button.setTitleColor(UIColor.blue, for: .normal)
    button.translatesAutoresizingMaskIntoConstraints = false
    return button
}()

//Then add them as subViews in the viewDidLoad method and set some constraints. 

override func viewDidLoad() {
    super.viewDidLoad()

    view.addSubview(myTextField)
    myTextField.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myTextField, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myTextField, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1, constant: -100).isActive = true

    view.addSubview(myLabel)
    myLabel.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myLabel.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myLabel, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1, constant: 0).isActive = true


    view.addSubview(myButton)
    myButton.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myButton.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myButton, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myButton, attribute: .top, relatedBy: .equal, toItem: myTextField, attribute: .bottom, multiplier: 1, constant: 10).isActive = true

//This sets the function for when the button is pressed 
    myButton.addTarget(self, action: #selector(ViewController.myButtonPressed), for: .touchUpInside)
}

//Add code here to when the button is pressed
func myButtonPressed() {

    myLabel.text = myTextField.text

}

}

如何显示用户输入的文本？ Swift 3.0

1 个答案: