Cara membuat kalkulator di Swift 5

Persyaratan sistem operasi dan perangkat keras

Pilihan lingkungan pengembangan

• Xamarin . Aplikasi pada platform ini ditulis menggunakan C #. Dengan Xamarin, Anda dapat membuat aplikasi Android atau iOS asli. Pengembangan dapat dilakukan dengan menggunakan Visual Studio. Meskipun ada keuntungan seperti itu, kemungkinan besar. beberapa fragmen aplikasi perlu ditulis secara terpisah untuk setiap platform
• React Native. React , -. . , - , - . , .
• Flutter. , Flutter Dart Google. , , . , Flutter — React Native, . Dart, -
• PhoneGap/Cordova. Nitobi, Adobe. , PhoneGap, Apache Cordova, WebView,
• Unity. IOS, . , . gamedev.

Membuat kalkulator

@IBOutlet var holder: UIView!

    var firstNumber = 0
    var resultNumber = 0
    var currentOperations: Operation?
        enum Operation {
        case add, subtract, multiply, divide
    }

    private var resultLabel: UILabel = {
        let label = UILabel()
        label.text = "0"
        label.textColor = .white
        label.textAlignment = .right
        label.font = UIFont(name: "Helvetica", size: 100)
        return label
    }()

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        setupNumberPad() //,      
    }

    private func setupNumberPad() {
        let FontSize:CGFloat = 25 
        //      
        let buttonSize: CGFloat = view.frame.size.width / 4 
        //    1/4
        let zeroButton = UIButton(frame: CGRect(x: 0, y: holder.frame.size.height-buttonSize, width: buttonSize*3, height: buttonSize))
        //  UIButton     
        zeroButton.setTitleColor(.black, for: .normal) 
        //    
        zeroButton.backgroundColor = .white
        //   
        zeroButton.setTitle("0", for: .normal) 
        //    0
        zeroButton.titleLabel?.font = UIFont(name: "Helvetica", size: FontSize)
        // , family    
        zeroButton.tag = 1 
        //         
        holder.addSubview(zeroButton)  //    holder 
        zeroButton.addTarget(self, action: #selector(zeroTapped), for: .touchUpInside) 
        //       
 

        for x in 0..<3 {
            let button_row_1 = UIButton(frame: CGRect(x: buttonSize * CGFloat(x), y: holder.frame.size.height-(buttonSize*2), width: buttonSize, height: buttonSize))
            //   x     x
            button_row_1.setTitleColor(.black, for: .normal) //
            button_row_1.backgroundColor = .white // 
            button_row_1.setTitle("\(x+1)", for: .normal) //  
            holder.addSubview(button_row_1) //    
            button_row_1.tag = x+2 // .. 1  ,   2
            button_row_1.addTarget(self, action: #selector(numberPressed(_:)), for: .touchUpInside)
            // 
        }

       for x in 0..<3 {
            let button_row_2 = UIButton(frame: CGRect(x: buttonSize * CGFloat(x), y: holder.frame.size.height-(buttonSize*3), width: buttonSize, height: buttonSize))
            button_row_2.setTitleColor(.black, for: .normal)
            button_row_2.backgroundColor = .white
            button_row_2.setTitle("\(x+4)", for: .normal)
            button_row_2.addSubview(button_row_2)
            button_row_2.tag = x+5
            button_row_2.addTarget(self, action: #selector(numberPressed(_:)), for: .touchUpInside)
        }
        
        for x in 0..<3 {
            let button_row_3 = UIButton(frame: CGRect(x: buttonSize * CGFloat(x), y: holder.frame.size.height-(buttonSize*4), width: buttonSize, height: buttonSize))
            button_row_3.setTitleColor(.black, for: .normal)
            button_row_3.backgroundColor = .white
            button_row_3.setTitle("\(x+7)", for: .normal)
            holder.addSubview(button_row_3)
            button_row_3.tag = x+8
            button_row_3.addTarget(self, action: #selector(numberPressed(_:)), for: .touchUpInside)
        }
    

        let clearButton = UIButton(frame: CGRect(x: 0, y: holder.frame.size.height-(buttonSize*5), width: view.frame.size.width - buttonSize, height: buttonSize))
        clearButton.setTitleColor(.black, for: .normal)
        clearButton.backgroundColor = .init(red: 0, green: 2, blue: 0.8, alpha: 1) //       rgb
         clearButton.titleLabel?.font = UIFont(name: "Helvetica", size: FontSize-4) //     
        clearButton.setTitle("CE", for: .normal)
        holder.addSubview(clearButton) //     holder
        clearButton.addTarget(self, action: #selector(clearResult), for: .touchUpInside) //  

        let operations = ["=","+", "-", "x", "÷"] //  

        for x in 0..<5 {
            let button_operand = UIButton(frame: CGRect(x: buttonSize * 3, y: holder.frame.size.height-(buttonSize * CGFloat(x+1)), width: buttonSize, height: buttonSize))
            button_operand.setTitleColor(.black, for: .normal)
            button_operand.backgroundColor = .init(red: 2, green: 0.8, blue: 0, alpha: 1) // 
            button_operand.setTitle(operations[x], for: .normal)
            holder.addSubview(button_operand)
            button_operand.tag = x+1 
            // ,       
            button_operand.titleLabel?.font = UIFont(name: "Helvetica", size: FontSize)
            button_operand.addTarget(self, action: #selector(operationPressed(_:)), for: .touchUpInside)
        }

    resultLabel.frame = CGRect(x: 20, y: clearButton.frame.origin.y - 110.0, width: view.frame.size.width - 40, height: 100)
    holder.addSubview(resultLabel)
} //    

Bekerja dengan penangan

    @objc func clearResult() {
        resultLabel.text = "0" //    0
        currentOperations = nil //    
        firstNumber = 0 //      0
    }
    
    @objc func zeroTapped() {
        //    
        if resultLabel.text != "0" {
            if let text = resultLabel.text {
                resultLabel.text = "\(text)\(0)" //  
            }
        }
    }

    @objc func numberPressed(_ sender: UIButton) {
        let tag = sender.tag - 1
        
        if resultLabel.text == "0" {
            resultLabel.text = "\(tag)"
        }
        else if let text = resultLabel.text {
        //   
            resultLabel.text = "\(text)\(tag)"
        }
    }

 @objc func operationPressed(_ sender: UIButton) {
        let tag = sender.tag
        
        if let text = resultLabel.text, let value = Int(text), firstNumber == 0 {
            //   
            firstNumber = value
            resultLabel.text = "0"
        }
        
        if tag == 1 {
            if let operation = currentOperations {
                var secondNumber = 0
                if let text = resultLabel.text, let value = Int(text) {
                    secondNumber = value
                }
                
                switch operation {
                case .add:
                    
                    firstNumber = firstNumber + secondNumber
                    secondNumber = 0 //  
                    resultLabel.text = "\(firstNumber)" 
                    currentOperations = nil
                    firstNumber = 0 //     Label 
                    
                    break
                    
                case .subtract:
                    firstNumber = firstNumber - secondNumber
                    secondNumber = 0
                    resultLabel.text = "\(firstNumber)"
                    currentOperations = nil
                    firstNumber = 0
                    
                    break
                    
                case .multiply:
                    firstNumber = firstNumber * secondNumber
                    secondNumber = 0
                    resultLabel.text = "\(firstNumber)"
                    currentOperations = nil
                    firstNumber = 0
                    
                    break
                    
                case .divide:
                    firstNumber = firstNumber / secondNumber
                    secondNumber = 0
                    resultLabel.text = "\(firstNumber)"
                    currentOperations = nil
                    firstNumber = 0
                    break
                }
            }
        }
        else if tag == 2 {
            currentOperations = .add 
            //     .    ,    
        }
        else if tag == 3 {
            currentOperations = .subtract
        }
        else if tag == 4 {
            currentOperations = .multiply
        }
        else if tag == 5 {
            currentOperations = .divide
        }
    }
}

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