Question

伙计们，请你帮忙解决这个错误。我正在与<class> <employee type="Senior Software Developer"> <empid>A433568</empid> <empname>John Mathews</empname> <address>6th Avenue Street</address> </employee> <employee type="Junior Software Developer"> <empid>A433678</empid> <empname>Sunny Mathews</empname> <address>5th Avenue Street</address> </employee> <employee type="Trainee"> <empid>A434567</empid> <empname>Brad Hodge</empname> <address>4th Avenue Street</address> </employee> <employee type="Senior Software Developer"> <empid>A433599</empid> <empname>Glenn Powell</empname> <address>6th Avenue Street</address> </employee> <employee type="Senior Software Developer"> <empid>A433588</empid> <empname>Recordo Mathews</empname> <address>6th Avenue Street</address> </employee> </class>合作。我在这段代码中有错误。具体在代码的最后部分（返回项）。错误描述告诉使用未解析的标识符＆＃39;项目＆＃39;

CoreData

错误的具体代码是

退货

Answer 1

您在do {}块中初始化了项目，因此函数中的项目不知道什么是项目变量，因此您应该在函数的开头初始化项目变量，以便： -

class func fetchEntities(className:NSString, withPredicate predicate:NSPredicate?, managedObjectContext:NSManagedObjectContext)->NSArray{
let items: NSArray!
let fetchRequest:NSFetchRequest = NSFetchRequest()
let entetyDescription:NSEntityDescription = NSEntityDescription.entityForName(className as! String, inManagedObjectContext: managedObjectContext)!

fetchRequest.entity = entetyDescription

if predicate != nil{
    fetchRequest.predicate = predicate!
}

fetchRequest.returnsObjectsAsFaults = false


do{
   items = try managedObjectContext.executeFetchRequest(fetchRequest)

} catch {

    print("error")

}
return items
}

Answer 2

代码

do{
   let items = try managedObjectContext.executeFetchRequest(fetchRequest)

}

创建一个新范围。在该范围之外items无法访问。

使用未解析的标识符

2 个答案: