Question

我目前正在玩swift。我正在关注Lynda.com手表套件教程，该教程通过创建一个简单的手表计算器来引导观众。

以下方法抛出错误＆＃34;一行上的连续语句必须用＆＃39;;＆＃39;＆＃34;＆＃34;

分隔

 func updateText(){
         guard let labelInt:Int64 = Int64(labelString) else {
             label.setText("Number is too big")
             return
         }
         label.setText("\(labelInt)")
     }

由于某些原因，xCode不识别保护，因此该语句会抛出错误。我看过多个使用后卫的教程，我错过了什么？该教程似乎使用完全相同的方法字符到字符没有问题。

整个文件供参考：

 import WatchKit
 import Foundation

 class InterfaceController: WKInterfaceController {

     var labelString:String = "0"

     @IBOutlet var label: WKInterfaceLabel!
     @IBAction func tapped0(){tappedNumber(0)}
     @IBAction func tapped1(){tappedNumber(1)}
     @IBAction func tapped2(){tappedNumber(2)}
     @IBAction func tapped3(){tappedNumber(3)}
     @IBAction func tapped4(){tappedNumber(4)}
     @IBAction func tapped5(){tappedNumber(5)}
     @IBAction func tapped6(){tappedNumber(6)}
     @IBAction func tapped7(){tappedNumber(7)}
     @IBAction func tapped8(){tappedNumber(8)}
     @IBAction func tapped9(){tappedNumber(9)}

     func tappedNumber(num:Int){
         labelString = labelString.stringByAppendingString("\(num)")
         updateText()
     }

     func updateText(){
         guard let labelInt:Int64 = Int64(labelString) else {
             label.setText("Number is too big")
             return
         }
         label.setText("\(labelInt)")
     }

     @IBAction func tappedPlus(){

     }
     @IBAction func tappedMinus(){

     }
     @IBAction func tappedClear(){

     }
     @IBAction func tappedEquals(){

     }

     override func awakeWithContext(context: AnyObject?) {
         super.awakeWithContext(context)

         // Configure interface objects here.
     }

     override func willActivate() {
         // This method is called when watch view controller is about to be visible to user
         super.willActivate()
     }

     override func didDeactivate() {
         // This method is called when watch view controller is no longer visible
         super.didDeactivate()
     }

 }

Answer 1

guard表达式仅在Swift 2 / Xcode 7中可用

Xcode 7的最终版本已于几天前（9月17日）发布。

警卫让 - 一条线上的连续陈述必须用＆＃39;;＆＃39; 3

1 个答案: