swift-26加法计算器

我以前做的swift笔记, 之前都是整理在onenote上, 最近想到整理出博客. 也方便自己查找, 可以当做自己的一份文档.

import UIKit

class ViewController: UIViewController {

    var numText1: UITextField?
    var numText2: UITextField?
    var sumLabel: UILabel?
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
        
    }

    func setupUI() {
        let textField1 = UITextField(frame: CGRect(x: 20, y: 40, width: 100, height: 30))
        numText1 = textField1
        textField1.borderStyle = UITextBorderStyle.roundedRect
        textField1.text = "0"
        view.addSubview(textField1)
        
        let textField2 = UITextField(frame: CGRect(x: 140, y: 40, width: 100, height: 30))
        numText2 = textField2
        textField2.borderStyle = UITextBorderStyle.roundedRect
        textField2.text = "0"
        view.addSubview(textField2)
        
        let label1 = UILabel(frame: CGRect(x: 120, y: 40, width: 20, height: 30))
        label1.text = "+"
        label1.textAlignment = .center
        view.addSubview(label1)

        let label2 = UILabel(frame: CGRect(x: 240, y: 40, width: 20, height: 30))
        label2.text = "="
        label2.textAlignment = .center
        view.addSubview(label2)

        let label3 = UILabel(frame: CGRect(x: 260, y: 40, width: 50, height: 30))
        sumLabel = label3
        label3.text = "0"
        label3.textAlignment = .right
        view.addSubview(label3)
        
        let button1 = UIButton()
        button1.center = view.center
        button1.setTitle("计算", for: .normal)
        button1.sizeToFit()
        button1.setTitleColor(UIColor.black, for: .normal)
        button1.addTarget(self, action: #selector(calc), for: .touchUpInside)
        view.addSubview(button1)
    }

    func calc() {
        print(#function)
        let num1 = Int(numText1?.text ?? "")
        print(num1)
        let num2 = Int(numText2?.text ?? "")
        
        guard let text1 = num1,
            let text2 = num2 else {
                print("必须都输入数字才能计算")
            return
        }
        
        sumLabel?.text = "\(text1 + text2)"
        
    }

}