Question

我试图制作一个按类比例分配租金的应用，但每当我插入所有数据并按下计算按钮时，它只会显示“＆＃34; inf＆＃34;在文本框中。

代码如下：

   class ViewController: UIViewController {




@IBAction func tapIt(sender: UITapGestureRecognizer) {
    monthlyRent.resignFirstResponder()
    moveInMonth.resignFirstResponder()
    moveInDay.resignFirstResponder()
    moveInYear.resignFirstResponder()
    billOn.resignFirstResponder()
}

override func viewDidLoad() {
    super.viewDidLoad()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()


}

var daysInMonth : Int = Int()
var temp : Int = Int()
var daysLivingThere : Int = Int()
var rentPerDay : Double = Double()
var billingDays2 : Int = Int()
var proratedRent : Double = Double()
var addIn = 1
var passingData : String = String()
var dollar = "$"

@IBOutlet var monthlyRent: UITextField!

@IBOutlet var moveInMonth: UITextField!

@IBOutlet var moveInDay: UITextField!

@IBOutlet var moveInYear: UITextField!

@IBOutlet var billOn: UITextField!

@IBOutlet var fieldA: UITextField!


@IBAction func calculate(sender: UIButton) {


    let rentMonthly : Double? = Double(monthlyRent.text!)
    let dayMoveIn : Int? = Int(moveInDay.text!)
    let billingDays : Int? = Int(billOn.text!)
    let monthDays : Double? = Double(daysInMonth)


    switch moveInMonth
    {
    case 1, 3, 5, 7, 8, 10, 12:
        daysInMonth = 31
    case 4, 6, 9, 11:
        daysInMonth = 30
    case 2:
        daysInMonth = 28
    default:
        break
    }


    billingDays2 = billingDays! - addIn
    temp = daysInMonth - dayMoveIn!
    daysLivingThere = temp + billingDays2

    rentPerDay = rentMonthly! / monthDays!
    let a : Double? = Double(daysLivingThere)
    proratedRent = rentPerDay + a!

    let b : String? = String(proratedRent)
    fieldA.text = dollar + b!


}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if (segue.identifier == "btnSubmitSegue") {
        let svc = segue.destinationViewController as! SecondViewController;
        svc.dataPassed = fieldA.text!
    }
}

}

所有代码都位于按钮内。我想将数据从文本框传输到辅助视图控制器，并且迫切需要文本框才能工作。

Answer 1

可能是因为monthDays设置在daysInMonth之前，它依赖于let monthDays :...，将moveInMonth行移到var selectedOptions = $('#cols option:selected').text();切换之后。

Answer 2

再加上David Berry所说的，我在游乐场中运行它并且无法编译，因为“错误：在初始化之前使用常量'daysInMonth'”。确保初始化这些值，你应该很好。

Answer 3

大卫是对的：

改变这个：

let rentMonthly : Double? = Double(monthlyRent.text!)
let dayMoveIn : Int? = Int(moveInDay.text!)
let billingDays : Int? = Int(billOn.text!)
let monthDays : Double? = Double(daysInMonth)


switch moveInMonth
{
case 1, 3, 5, 7, 8, 10, 12:
    daysInMonth = 31
case 4, 6, 9, 11:
    daysInMonth = 30
case 2:
    daysInMonth = 28
default:
    break
}

到此：

let rentMonthly : Double? = Double(monthlyRent.text!)
let dayMoveIn : Int? = Int(moveInDay.text!)
let billingDays : Int? = Int(billOn.text!)


switch moveInMonth
{
case 1, 3, 5, 7, 8, 10, 12:
    daysInMonth = 31
case 4, 6, 9, 11:
    daysInMonth = 30
case 2:
    daysInMonth = 28
default:
    break
}

let monthDays : Double? = Double(daysInMonth)

Swift，计算数据并将其插入文本字段

3 个答案: