Question

我声明了一个全局变量_dataArray：

    var _dataArray : Array<AnyObject> = Array();

然后定义一个函数：

    func fetchCoreData(userName: String){
    var context : NSManagedObjectContext = appDel.managedObjectContext!
    var request = NSFetchRequest(entityName: "GoodModel")
    request.returnsObjectsAsFaults = false
    request.predicate = NSPredicate(format: "uid = %@",_userUid )
    let _dataArray = context.executeFetchRequest(request, error: nil)!
    if(_dataArray.count == 0){
        println("We need to parse JSON")
        self.parseJSON()
    }else{
        println("Display from CoreData, we do not need to parse JSON!")
        println("_dataArray.count:%d",_dataArray.count)
        self.tableView.reloadData()
    }
}

从控制台，我可以看到这个_dataArray中有20个对象。但在以下函数中，_dataArray的计数为0.为什么??????????

@IBAction func endorseButton(sender: AnyObject, forEvent event: UIEvent) {
    println(_dataArray.count)
    let touches = event.allTouches()
    let touch: AnyObject? = touches?.anyObject()
    let currentTouchPosition = touch?.locationInView(self.tableView)
    let indexPath = self.tableView.indexPathForRowAtPoint(currentTouchPosition!)?
    if let ip = indexPath {
        var data:NSManagedObject = _dataArray[ip.row] as NSManagedObject
    }
}

Answer 1

问题在于这一行：

let _dataArray = context.executeFetchRequest(request, error: nil)!

您声明本地 _dataArray。

您应该省略let：

_dataArray = context.executeFetchRequest(request, error: nil)!

致命错误：无法索引空缓冲区

1 个答案: