Uitableview Swift-致命错误：Can'；t展开可选。无

我正在尝试获取核心数据对象并在UITableView中显示它们

我有一个

DBEmployess

对象，当我试图获取它的

name

属性时，我得到一个错误

fatal error: Can't unwrap Optional.None

这是我的密码

dbemployeess.h

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@class DBProjects;

@interface DBEmployess : NSManagedObject

@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSString * designation;
@property (nonatomic, retain) NSNumber * age;
@property (nonatomic, retain) DBProjects *projects;

@end

#import "MBProgressHUD.h"
#import "DBEmployess.h"

MyProject桥接头.h

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@class DBProjects;

@interface DBEmployess : NSManagedObject

@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSString * designation;
@property (nonatomic, retain) NSNumber * age;
@property (nonatomic, retain) DBProjects *projects;

@end

#import "MBProgressHUD.h"
#import "DBEmployess.h"

UITableView方法

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    var cell : UITableViewCell? = tableView.dequeueReusableCellWithIdentifier("Cell") as? UITableViewCell
    if(cell == nil) {
        cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
    }

    let employee : DBEmployess? = self.employessArray.objectAtIndex(indexPath.row) as? DBEmployess

    if(employee != nil) {
        cell!.textLabel.text = employee!.valueForKey("name").description
    }

    return cell!
}

如果我打印

employee

对象，我会得到

(DBEmployess?) employee = Some {
  Some = 0x0000000111702670 {
    CoreData.NSManagedObject = {
      ObjectiveC.NSObject = {}
    }
  }

知道我做错了什么吗

更新：

我发现实际的问题是在保存核心数据时。如果我在

NSManagedObject

的属性中设置硬编码字符串，那么它完全可以访问，并且显示在UITableView中。但是如果我设置了

UITextField

text的值，它确实成功保存了，但无法展开

这是我的核心数据

func addNewEmployee() {
    let delegate = UIApplication.sharedApplication().delegate as AppDelegate
    let context = delegate.managedObjectContext
    let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName("DBEmployess", inManagedObjectContext: context) as NSManagedObject
    newManagedObject.setValue(self.txtName.text, forKey: "name")
    newManagedObject.setValue(self.txtDesignation.text, forKey: "designation")
    newManagedObject.setValue(self.txtAge.text, forKey: "age")

    // Save the context.
    var error: NSError? = nil
    if !context.save(&error) {
        var alert = UIAlertController(title: "Error", message: "Could not save employee \(error!.localizedDescription)", preferredStyle: UIAlertControllerStyle.Alert)
        alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
        self.presentViewController(alert, animated: true, completion: nil)

    } else {
        var alert = UIAlertController(title: "Saved", message: "Employee saved successfully", preferredStyle: UIAlertControllerStyle.Alert)
        alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
        self.presentViewController(alert, animated: true, completion: nil)
    }
}

---

如果可选对象为

nil

，则无法将其展开；否则你会像以前一样崩溃。对于

单元格

和

员工

都是如此。哪一行抛出异常？我有println（）DBEmployess，它似乎不是null。您可以在我的问题中看到log。那么，让我再试一次，哪一行抛出了execption？我无法访问

name

property如果

name

is

nil

，这将出错，因为

valueForKey

返回可选值。我认为如果让name=employee？.valueForKey（“name”）{cell！.textLabel.text=name}或者{//NO name！}