Question

我在向计算器添加历史记录时遇到问题（lblHistory标签）我想将以前的输入存储在lblHistory : UILabel

中

但它所做的就是存储第一个数字及其操作。

是否有任何算法可以存储计算器的所有先前输入？

这是我的班级MyCalculator.swift

Class MyCalculator

//
//  MyCalculator.swift
//  Calculator
//
//  Created by
//  abcdefgh
//

import Foundation

class MyCalculator
{
    var memory: Float = 0

    var percentnum: Float = 0

    var currentNum: Float = 0

    var result: Float = 0

    var operation: String = ""

    var isOperation: Bool = false

    var isRepeatOperation: Bool = false

    var isNum: Bool = false

    func operation (operation:String) -> Float
    {
        if operation == "+" {
            result = result + currentNum
        }
        else if operation == "-" {
            result = result - currentNum
        }
        else if operation == "*" {
            result = result * currentNum
        }
        else if operation == "/" {
            result = result / currentNum
        }
        return result
    }

    func percent(percentNum:Float) ->Float
    {
        let valpercent = percentNum * 0.01
        result = result * valpercent
        return result
    }

    func clearAll() {
        result = 0
        currentNum = 0
        isNum = false

    }

}

这是我的计算器的视图控制器。

查看控制器

/  ViewController.swift
//  Calculator
//
//  Created by 
//  abcdefgh
//

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    //Start Calculator


    //Label History: This is where the history is displayed
    @IBOutlet weak var lblHistory: UILabel!


    //Label Result: This is where the result is displayed
    @IBOutlet weak var lblResult: UILabel!


    //Initialization
    let calc = MyCalculator() //call the class MyCalculator

//Function for Number Inputs
@IBAction func btnNumInput(sender: AnyObject)
{
    let num = sender.currentTitle
    if calc.isNum == false
    {
        lblResult.text = num
        calc.isNum = true
    }
    else
    {
        lblResult.text = lblResult.text! + num!!
    }
    calc.isRepeatOperation = false
    lblResult.adjustsFontSizeToFitWidth = true
}

//Function for Operations
@IBAction func btnOperations(sender: AnyObject)
{
    calc.isNum = false
    if calc.isOperation && !calc.isRepeatOperation
    {
        calc.currentNum = Float(lblResult.text!)!
        if calc.operation == "+"
        {
            calc.result = calc.operation("+")
        }
        else if calc.operation == "-"
        {
            calc.result = calc.operation("-")
        }
        else if calc.operation == "*"
        {
            calc.result = calc.operation("*")
        }
        else if calc.operation == "/"
        {
            calc.result = calc.operation("/")
        }
        if calc.operation == "/" && calc.currentNum == 0
        {
            lblResult.text = "Cannot divide by zero"
            lblResult.adjustsFontSizeToFitWidth = true
        }
        else
        {
            let stringresult = String(format:"%g" , calc.result)
            lblResult.text = "\(stringresult)"
            calc.isOperation = false
        }
    }
    else
    {
        calc.result = Float(lblResult.text!)!
    }

    let strresult = String(format:"%g", calc.result)
    calc.operation = sender.currentTitle!!
    lblHistory.text = strresult + calc.operation
    calc.isOperation = true
    calc.isRepeatOperation = true
}

从这里的代码：

let strresult = String(format:"%g", calc.result)
calc.operation = sender.currentTitle!!
lblHistory.text = strresult + calc.operation

这应该存储历史标签的任何输入，但它只存储第一个输入及其运算符。

结果：

2+2 =4 //this is the input variables and operation
//the result is 4 and display on lblResult: UILabel
2+ // the "2+" is only stored in lblHistory: UILabel not the whole input itself

在计算器上添加历史记录（iOS）

0 个答案: