发送到新的View Controller的数据为零，展开可选值 [英] Data being sent to new View Controller is nil, unwrapping an Optional Value

问题描述

当我尝试将事件类的详细信息传递给另一个控制器时，我会收到一条错误，说致命错误：意外发现无法解开可选值。

这是发送信息的视图控制器：

  var eventDetailscontrollers：EventDetailsController！ 
 
 func showDetailView（event：Events）{
 let mainStoryBoarrd：UIStoryboard = UIStoryboard（name：Main，bundle：nil）
 let detailsViewController：UIViewController = mainStoryBoarrd.instantiateViewControllerWithIdentifier eventDetailsID）
 eventDetailscontrollers？.event = event //将所有信息发送为nil 
 eventDetailscontrollers.event = event //这会导致错误
 
 print（event.name） //打印事件名称
 
 self.presentViewController（detailsViewController，动画：true，completion：nil）
} 
  

这是我将数据发送到的类：

  var event：活动！ {
 didSet {
 eventPriceLabel.text = event！.date // does nothing 
} 
} 
 
 override func viewDidLoad（）{
 super.viewDidLoad（）
 
 let string = event？.name 
 print（string）// prints null 
} 
  / pre> 
 
 
我的活动类：
 类事件：NSObject { 
 var name：String！ 
 var date：String！ 
 var address：String！ 
 var ticketPrice：Int！ 
  
 
 
解决方案
问题在这里：
  func showDetailView（event：Events）{
 let mainStoryBoarrd：UIStoryboard = UIStoryboard（name：Main，bundle：nil）
 let detailsViewController：UIViewController = mainStoryBoarrd.instantiateViewControllerWithIdentifier（eventDetailsID）
 eventDetailscontrollers？.event = event //将所有信息发送为nil 
 eventDetailscontrollers.event =事件//这会导致错误
 
 print（event.name）// this打印事件名称
 
 self.presentViewController（detailsViewController，动画：true，completion：nil）
} 
  
您有两个变量应该相同：
  func showDetailView（event：Events）{
 let mainStoryBoarrd：UIStoryboard = UIStoryboard（name：Main，bundle：nil）
 eventDetailscontrollers = mainStoryBoarrd.instantiateViewControllerWithIdentifier（ eventDetailsID）
 eventDetailscontrollers？.event = event //将所有信息发送为nil 
 eventDetailscontrollers.event = event //这会导致错误
 
 print（event.name）/ / print打印事件名称
 
 self.presentViewController（eventDetailscontrollers，animated：true，completion：nil）
} 
  
 
When I try to pass details of my Event class to another controller I get an error saying "fatal error: unexpectedly found nil while unwrapping an Optional value".


This is my view controller that sends the info:
var eventDetailscontrollers: EventDetailsController!

func showDetailView(event: Events){
    let mainStoryBoarrd: UIStoryboard = UIStoryboard(name:"Main", bundle:nil)
    let detailsViewController: UIViewController = mainStoryBoarrd.instantiateViewControllerWithIdentifier("eventDetailsID")
    eventDetailscontrollers?.event = event //this sends all info as nil
    eventDetailscontrollers.event = event //this causes error

    print(event.name)      // this prints event name fine

    self.presentViewController(detailsViewController, animated: true, completion: nil)
}
This is the class I send the data to:
var event: Events!   {
    didSet  {
        eventPriceLabel.text = event!.date //does nothing
    }
}

override func viewDidLoad() {
    super.viewDidLoad()

    let string = event?.name
    print(string)// prints null
}
My Events class:
class Events: NSObject {
    var name: String!
    var date: String!
    var address: String!
    var ticketPrice: Int!

解决方案
The issue is here:
func showDetailView(event: Events){
    let mainStoryBoarrd: UIStoryboard = UIStoryboard(name:"Main", bundle:nil)
    let detailsViewController: UIViewController = mainStoryBoarrd.instantiateViewControllerWithIdentifier("eventDetailsID")
    eventDetailscontrollers?.event = event //this sends all info as nil
    eventDetailscontrollers.event = event //this causes error

    print(event.name)      // this prints event name fine

    self.presentViewController(detailsViewController, animated: true, completion: nil)
}
You have two variables that should be the same:
func showDetailView(event: Events){
    let mainStoryBoarrd: UIStoryboard = UIStoryboard(name:"Main", bundle:nil)
    eventDetailscontrollers = mainStoryBoarrd.instantiateViewControllerWithIdentifier("eventDetailsID")
    eventDetailscontrollers?.event = event //this sends all info as nil
    eventDetailscontrollers.event = event //this causes error

    print(event.name)      // this prints event name fine

    self.presentViewController(eventDetailscontrollers, animated: true, completion: nil)
}


                        
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