ios - 此类对于键 不符合键值编码，其中 不在代码中(swift，Xcode 6)

Question

我输入了一个程序，其代码如下，来自一个教程，试图在多年后重新开始编码。

当我运行代码时，一切都会构建，但随后它会因上面的主题行错误而崩溃，命名一个没有出现在我的代码中任何地方的键(“helloText”)。完整的错误输出如下。

扭曲:有一次我将其中一个导出命名为“helloText”(现在命名为“nameTextField”)。

我查看了所有与我能找到的项目相关的文件，但找不到“helloText”。我还尝试了“清洁”菜单项。

感谢您的指导。

//
//  ViewController.swift
//  ConstructOStraws
//
//  Created by Eric on 11/12/14.
//  Copyright (c) 2014 Eric. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        setupUI()
    }

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


    @IBOutlet weak var helloLabel: UILabel!
    @IBOutlet weak var nameTextField: UITextField!
    @IBOutlet weak var helloButton: UIButton!

    func setupUI(){

        helloLabel.text = "Hello Swift!"
        helloLabel.textColor = UIColor.redColor()
        helloLabel.textAlignment = NSTextAlignment.Center

        nameTextField.placeholder = "Enter your name"

    helloButton.setTitle("Say Hell", forState: .Normal)

    }


    @IBAction func sayHelloAction(sender: AnyObject) {

        let name = nameTextField.text

        if name.isEmpty {

            let alert = UIAlertController(title: "Error", message: "Please Enter a Name.", preferredStyle: UIAlertControllerStyle.Alert)

            alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))

            self.presentViewController(alert, animated: true, completion: nil)
        } else {

            helloLabel.text = "Hello \(name)"
        }
    }

}

错误:

2014-11-12 15:23:10.521 ConstructOStraws[2048:67817] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<ConstructOStraws.ViewController 0x7f82e866b420> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key helloText.'
*** First throw call stack:
(
    0   CoreFoundation                      0x00000001043b7f35 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000105efbbb7 objc_exception_throw + 45
    2   CoreFoundation                      0x00000001043b7b79 -[NSException raise] + 9
    3   Foundation                          0x00000001047cf7b3 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 259
    4   CoreFoundation                      0x0000000104301e80 -[NSArray makeObjectsPerformSelector:] + 224
    5   UIKit                               0x0000000104f08c7d -[UINib instantiateWithOwner:options:] + 1506
    6   UIKit                               0x0000000104d67f98 -[UIViewController _loadViewFromNibNamed:bundle:] + 242
    7   UIKit                               0x0000000104d68588 -[UIViewController loadView] + 109
    8   UIKit                               0x0000000104d687f9 -[UIViewController loadViewIfRequired] + 75
    9   UIKit                               0x0000000104d68c8e -[UIViewController view] + 27
    10  UIKit                               0x0000000104c87ca9 -[UIWindow addRootViewControllerViewIfPossible] + 58
    11  UIKit                               0x0000000104c88041 -[UIWindow _setHidden:forced:] + 247
    12  UIKit                               0x0000000104c9472c -[UIWindow makeKeyAndVisible] + 42
    13  UIKit                               0x0000000104c3f061 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 2628
    14  UIKit                               0x0000000104c41d2c -[UIApplication _runWithMainScene:transitionContext:completion:] + 1350
    15  UIKit                               0x0000000104c40bf2 -[UIApplication workspaceDidEndTransaction:] + 179
    16  FrontBoardServices                  0x0000000107a9b2a3 __31-[FBSSerialQueue performAsync:]_block_invoke + 16
    17  CoreFoundation                      0x00000001042ed53c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    18  CoreFoundation                      0x00000001042e3285 __CFRunLoopDoBlocks + 341
    19  CoreFoundation                      0x00000001042e3045 __CFRunLoopRun + 2389
    20  CoreFoundation                      0x00000001042e2486 CFRunLoopRunSpecific + 470
    21  UIKit                               0x0000000104c40669 -[UIApplication _run] + 413
    22  UIKit                               0x0000000104c43420 UIApplicationMain + 1282
    23  ConstructOStraws                    0x00000001041d661e top_level_code + 78
    24  ConstructOStraws                    0x00000001041d665a main + 42
    25  libdyld.dylib                       0x00000001066d5145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Answer 1

如果您重命名了 IBOutlets，那么您可能不会删除 Storyboard 中旧引用的引用，这些引用可能如下所示

如屏幕所示，删除带有黄色感叹号三角形 的导出引用。您可以通过在 View Controller 的 Storyboard 中右键单击 First Responder 旁边的 view controller 对象来访问此屏幕。