class ViewController: UIViewController {

    var 输入框一 : UITextField?
    var 输入框二 : UITextField?
    var 计算结果 : UILabel?
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        setupUI()
    }

    func setupUI() -> ()
    {
        //第一个输入框
        let oneText = UITextField(frame: CGRect(x: 10, y: 100, width: 80, height: 25))
        oneText.text = "0"
        oneText.textAlignment = .center
        oneText.borderStyle = .roundedRect
        view.addSubview(oneText)
        输入框一 = oneText
        
        //加号lanel
        let 加号 = UILabel(frame: CGRect(x: 100, y: 100, width: 25, height: 25))
        加号.text = "+"
        加号.textAlignment = .center
        view.addSubview(加号)
        
        //第二个输入框
         let twoText = UITextField(frame: CGRect(x: 135, y: 100, width: 80, height: 25))
        twoText.text = "0"
        twoText.textAlignment = .center
        twoText.borderStyle = .roundedRect
        view.addSubview(twoText)
        输入框二 = twoText;
        
        //等号按钮
        let 等号 = UIButton()
        等号.setTitle("=", for: UIControlState(rawValue: 0))
        等号.setTitleColor(UIColor.black(), for: UIControlState(rawValue: 0))
        等号.frame = CGRect(x: 225, y: 100, width: 25, height: 25)
//        等号.layer.borderWidth = 1
//        等号.layer.borderColor = UIColor.blue().cgColor
        view.addSubview(等号)
        等号.addTarget(self, action: #selector(calc), for: .touchUpInside)
        
        //结果label
        let 结果 = UILabel(frame: CGRect(x: 260, y: 100, width: 50, height: 25))
        结果.textAlignment = .left
        结果.text = "0"
        view.addSubview(结果)
        计算结果 = 结果
    }
    
    func calc() -> ()
    {
        print(#function)
//        结算结果?.text = "\(Int(输入框一?.text) ?? ""  + Int(输入框二?.text) ?? "" )"
        
        guard let num1 = Int(输入框一?.text ?? ""), num2 = Int(输入框二?.text ?? "") else{
            print("请输入数值")
            return
        }
        
        计算结果?.text = "\(num1+num2)"
    }
}

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