Question

也许你可以帮我在这里...... 我正在根据我的核心数据实体“植物”创建一个电子邮件正文

    let appDel: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let contxt: NSManagedObjectContext = appDel.managedObjectContext!
    let todos = NSFetchRequest(entityName: "Plants")
    var row = ""

    var circle = 0 as Int

    var fetchresults:Array<AnyObject> = []


    fetchresults = contxt.executeFetchRequest(todos, error: nil)!

    var endcircle = fetchresults.count as Int





    for index in 0...endcircle {

        let object = fetchresults[index] as! NSManagedObject
        var name = object.valueForKey("name") as! String


        var newlineimg = "nil"
        var newlineplant = (name) + "<br>"
        row = (row + newlineimg + newlineplant) as String

    }


   var mail = row

应用程序崩溃没有错误......我似乎无法在代码中找到错误...

Answer 1

你枚举一个循环，它应该是：

for index in 0...(endcircle - 1)

或

for index in 0..<endcircle

当你的fetchresults.count是例如5并且你从0到5枚举它实际上是6个循环，这就是它失败的原因。

Swift - For Loop崩溃了

1 个答案: