Question

我正在尝试将文字添加到UILabel的新行，现在它会替换当前文本。

如何将文字附加到UILabel？
如何向UILabel添加新行？

@IBAction func sign(sender: AnyObject) {


    if (ForUs.text == ""){
        input1 = 0

    } else{

        input1 = Int((ForUs.text)!)!
    }

    if (ForThem.text == ""){

        input2 = 0
    } else {
        input2 = Int((ForThem.text)!)!
    }

    ForUs.text?.removeAll()
    ForThem.text?.removeAll()

    input1total += input1
    input2total += input2

    Us.text = "\(input1total)"
    Them.text = "\(input2total)"


    if ( input1total >= 152){
        print("you win")

    }
    if (input2total >= 152){
        print("you lose")
    }

}

Answer 1

您发布的代码存在很多问题。

首先，明确代码。我们应该能够复制代码，粘贴它，例如游乐场，它应该工作。有时这是不可能的，但在你的情况下它是。

您的代码问题：

打开你的选项，每次你没有独角兽去世!!
您无法直接从Swift String转换为Int

此方法会以不会产生可选值的方式将String转换为Int。

// elaborate for extra clarity
let forUsTextNSString = forUsText as NSString
let forUSTextFloat = forUsTextNSString.floatValue
input1 = Int(forUSTextFloat)

这是更新的代码，现在编译：

// stuff I used to test this
var forUs = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
var forThem = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

var us = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
var them = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

// more stuff I used to test this
var input1 : Int = 0
var input2 : Int = 0
var input1total : Int = 0
var input2total : Int = 0

func sign() { // changed to non IB method, don't copy and paste this

    // unwrap some optionals (google nil coalescing operator)
    let forUsText = forUs.text ?? ""
    let forThemText = forThem.text ?? ""
    var usText = us.text ?? ""
    var themText = them.text ?? ""

    // elaborate way to convert String to Int (empty string returns a 0)
    let forUsTextNSString = forUsText as NSString
    let forUSTextFloat = forUsTextNSString.floatValue
    input1 = Int(forUSTextFloat)

    // compact method
    input1 = Int((forUsText as NSString).floatValue)
    input2 = Int((forThemText as NSString).floatValue)

    forUs.text = ""
    forThem.text = ""

    input1total += input1
    input2total += input2

    us.text = "\(input1total)"
    them.text = "\(input2total)"


    if ( input1total >= 152){
        print("you win")

    }
    if (input2total >= 152){
        print("you lose")
    }    
}

现在回答这个问题：

UILabel有一个属性numberOfLines
\n用于在文字中插入换行符

增加numberOfLines并在新文本之前添加\n的新文字。

usText += "\n\(input1total)"
themText += "\n\(input2total)"

// change += 1 to = 2 if that is what you actually need
us.numberOfLines += 1
them.numberOfLines += 1

us.text = usText
them.text = themText

在UILabel的新行上添加文本

1 个答案: