如何显示来自用户输入的文本？ Swift 3.0

Question

我是swift语言的新手（3.0）。我正在为iOS的新应用程序工作。我怎样才能创建一个文本框，用户键入输入，按下按钮，然后显示按钮下的文本？谢谢！

Answer 1

您可以使用故事板或以编程方式执行此操作。这两种方法都可以作为的Xcode 8的斯威夫特3

故事板

1. 在UITextField，一个UIButton和UILabel从库中拖拽，在您查看控制器
2. 创建一个IBOutlet的UITextField和UILabel到您的ViewController.swift文件。
3. 然后为UIButton创建一个IBAction到同一个ViewController.swift文件。

4. 编写此代码为您的按钮操作功能：

   myLabel.text = myTextField.text

你的整个代码应该是这样的：

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. 

} 
} 

或者编程：

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 

} 

}