IOS swift中的“NSUnknownKeyException”

我不熟悉使用swift进行IOS开发。现在我尝试将UItableViewController与多个不同的单元格一起使用。但是，多个单元格使用相同的数据源。 这是我在tableviewController类中的代码

import UIKit

class plantTableViewController: UITableViewController {

var plantsHelper = [PlantsHelper]()

override func viewDidLoad() {
    super.viewDidLoad()

    //add data
    loadSample()
}

func loadSample()
{
    let photo1 = UIImage(named: "bestplace")!
    let plantsHelper1 = PlantsHelper(name: "Best Place", photo: photo1, comment: "Find out the best place in your home to plant a plants!")!

    let photo2 = UIImage(named: "recommandplant")!
    let plantsHelper2 = PlantsHelper(name: "Recommanded Plants", photo: photo2, comment: "Find out what the fantastic plant we recommand!")!

    let photo3 = UIImage(named: "monitorplant")!
    let plantsHelper3 = PlantsHelper(name: "Monitor your plants", photo: photo3, comment: "Monitor your plants to give your plants a better environment!")!

    plantsHelper += [plantsHelper1, plantsHelper2, plantsHelper3]
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    // #warning Potentially incomplete method implementation.
    // Return the number of sections.
    return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete method implementation.
    // Return the number of rows in the section.
    return 3
}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    // Configure the cell...
    let plantHelper = plantsHelper[indexPath.row]
    if indexPath == 0
    {
        let cellIdentifier = "BestPlaceCell"
        let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! BestPlaceCell
        cell.bestPlaceNameLabel.text = plantHelper.name
        cell.bestPlacePhoto.image = plantHelper.photo
        cell.bestPlaceCommentLabel.text = plantHelper.comment
        return cell
    }
    else if indexPath == 1
    {
        let cellIdentifier2 = "RecommandCell"
        let cell2 = tableView.dequeueReusableCellWithIdentifier(cellIdentifier2, forIndexPath: indexPath) as! RecommandCell
        cell2.recommandName.text = plantHelper.name
        cell2.recommandComment.text = plantHelper.comment
        cell2.recommandPhoto.image = plantHelper.photo
        return cell2
    }
    else
    {
        let cellIdentifier3 = "MonitorCell"
        let cell3 = tableView.dequeueReusableCellWithIdentifier(cellIdentifier3, forIndexPath: indexPath) as! MonitorCell
        cell3.monitorName.text = plantHelper.name
        cell3.monitorComment.text = plantHelper.comment
        cell3.monitorPhoto.image = plantHelper.photo

        return cell3
    }


}
}

这是错误消息

    2015-11-05 14:34:50.142 HousePlantHelper[15177:2412448] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<HousePlantHelper.MonitorCell 0x7fac485484d0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key bestPlaceCommentLabel.'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000105f3fc65 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000107aaabb7 objc_exception_throw + 45
    2   CoreFoundation                      0x0000000105f3f8a9 -[NSException raise] + 9
    3   Foundation                          0x000000010635db53 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 259
    4   UIKit                               0x000000010685e67e -[UIView(CALayerDelegate) setValue:forKey:] + 149
    5   CoreFoundation                      0x0000000105e87d50 -[NSArray makeObjectsPerformSelector:] + 224
    6   UIKit                               0x0000000106ab64eb -[UINib instantiateWithOwner:options:] + 1506
    7   UIKit                               0x00000001068d1f7f -[UITableView _dequeueReusableViewOfType:withIdentifier:] + 308
    8   UIKit                               0x00000001068d21f5 -[UITableView dequeueReusableCellWithIdentifier:forIndexPath:] + 42
    9   HousePlantHelper                    0x0000000105948a83 _TFC16HousePlantHelper24plantTableViewController9tableViewfS0_FTCSo11UITableView21cellForRowAtIndexPathCSo11NSIndexPath_CSo15UITableViewCell + 3363
    10  HousePlantHelper                    0x0000000105948fdf _TToFC16HousePlantHelper24plantTableViewController9tableViewfS0_FTCSo11UITableView21cellForRowAtIndexPathCSo11NSIndexPath_CSo15UITableViewCell + 79
    11  UIKit                               0x00000001068df9e8 -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 508
    12  UIKit                               0x00000001068be208 -[UITableView _updateVisibleCellsNow:isRecursive:] + 2853
    13  UIKit                               0x00000001068d4869 -[UITableView layoutSubviews] + 210
    14  UIKit                               0x000000010685e9eb -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 536
    15  QuartzCore                          0x000000010a62ced2 -[CALayer layoutSublayers] + 146
    16  QuartzCore                          0x000000010a6216e6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
    17  QuartzCore                          0x000000010a621556 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
    18  QuartzCore                          0x000000010a58d86e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
    19  QuartzCore                          0x000000010a58ea22 _ZN2CA11Transaction6commitEv + 462
    20  UIKit                               0x00000001067dc9ed -[UIApplication _reportMainSceneUpdateFinished:] + 44
    21  UIKit                               0x00000001067dd6b1 -[UIApplication _runWithMainScene:transitionContext:completion:] + 2648
    22  UIKit                               0x00000001067dc095 -[UIApplication workspaceDidEndTransaction:] + 179
    23  FrontBoardServices                  0x00000001095a75e5 __31-[FBSSerialQueue performAsync:]_block_invoke_2 + 21
    24  CoreFoundation                      0x0000000105e7341c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    25  CoreFoundation                      0x0000000105e69165 __CFRunLoopDoBlocks + 341
    26  CoreFoundation                      0x0000000105e68947 __CFRunLoopRun + 887
    27  CoreFoundation                      0x0000000105e68366 CFRunLoopRunSpecific + 470
    28  UIKit                               0x00000001067dbb02 -[UIApplication _run] + 413
    29  UIKit                               0x00000001067de8c0 UIApplicationMain + 1282
    30  HousePlantHelper                    0x0000000105954e47 main + 135
    31  libdyld.dylib                       0x00000001081e0145 start + 1
    32  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

似乎是为每一行设置数据的问题。但我不知道我的代码有什么问题

---

有人能解决这个问题吗？

用完整准确的错误信息更新您的问题。并指出导致问题的原因。是否所有这些单元格都在故事板中设置为原型，并指定了相应的自定义UITableViewCell子类，以及您在代码中使用的相同重用标识符？代码的哪一行引发异常？所有单元格都设置在情节提要中，并且代码中的重用标识符不同……首先，您的if's for indexPath将始终解析为MonitorCell，因为indexPath从不为0或1。您需要检查indexPath.row。其次，错误表示MonitorCell没有属性bestPlaceCommentLabel。您的MonitorCell类是否具有该属性？