Question

当我尝试将tableview添加到新的选项卡式项目时，我收到一个无法解密的错误。

如果我将tableview添加到我的故事板，那么构建应用程序 - 没关系。但是，只要我将“委托”和“dataSource”拖动到带有方框图标的黄色圆圈以将其链接到我的控制器，构建就会失败。为什么会这样？

完全重复步骤：

在Xcode中创建一个新的“选项卡式视图”项目。
在故事板中，我将“表视图”拖到顶层故事板上。
我在“桌面视图”上“按住ctrl”，然后将“dataSource”和“delegate”拖动到故事板顶部的黄色圆圈+白框图标。
我打开FirstViewController.swift，然后尝试将UITableViewDelegate, UITableViewDataSource添加到类中。但是，这些都不会显示在自动完成中，就好像控制器不认为它们存在一样。 如果我命令点击一个，我会收到“找不到符号”。

FirstViewController.swift

//
//  FirstViewController.swift
//  To Do List
//
//  Created by Donald Pinkus on 12/14/14.
//  Copyright (c) 2014 Don Pinkus. All rights reserved.
//

import UIKit

class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

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

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


}

构建错误

2014-12-14 00:27:04.278 To Do List[11149:566768] -[To_Do_List.FirstViewController tableView:numberOfRowsInSection:]: unrecognized selector sent to instance 0x7faafae29ba0
2014-12-14 00:27:04.285 To Do List[11149:566768] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[To_Do_List.FirstViewController tableView:numberOfRowsInSection:]: unrecognized selector sent to instance 0x7faafae29ba0'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000105422f35 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000106f66bb7 objc_exception_throw + 45
    2   CoreFoundation                      0x000000010542a04d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x000000010538227c ___forwarding___ + 988
    4   CoreFoundation                      0x0000000105381e18 _CF_forwarding_prep_0 + 120
    5   UIKit                               0x0000000105f26212 -[UISectionRowData refreshWithSection:tableView:tableViewRowData:] + 2353
    6   UIKit                               0x0000000105f2a098 -[UITableViewRowData numberOfRows] + 97
    7   UIKit                               0x0000000105d928fc -[UITableView noteNumberOfRowsChanged] + 133
    8   UIKit                               0x0000000105d9203d -[UITableView reloadData] + 1316
    9   UIKit                               0x0000000105d9ad86 -[UITableView layoutSubviews] + 31
    10  UIKit                               0x0000000105d27973 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 521
    11  QuartzCore                          0x0000000109c25de8 -[CALayer layoutSublayers] + 150
    12  QuartzCore                          0x0000000109c1aa0e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
    13  UIKit                               0x0000000105d1b847 -[UIView(Hierarchy) layoutBelowIfNeeded] + 611
    14  UIKit                               0x0000000105e0ff06 -[UITabBarController _layoutViewController:] + 500
    15  UIKit                               0x0000000105e10014 -[UITabBarController _wrapperViewForViewController:] + 252
    16  UIKit                               0x0000000105e16e92 -[UITabBarController transitionFromViewController:toViewController:transition:shouldSetSelected:] + 378
    17  UIKit                               0x0000000105e13069 -[UITabBarController _setSelectedViewController:] + 311
    18  UIKit                               0x0000000105d1f5ce +[UIView(Animation) performWithoutAnimation:] + 65
    19  UIKit                               0x0000000105e10106 -[UITabBarController _selectDefaultViewControllerIfNecessaryWithAppearanceTransitions:] + 221
    20  UIKit                               0x0000000105e10dfe -[UITabBarController viewWillAppear:] + 121
    21  UIKit                               0x0000000105dd7821 -[UIViewController _setViewAppearState:isAnimating:] + 487
    22  UIKit                               0x0000000105d1a136 -[UIView(Hierarchy) _willMoveToWindow:withAncestorView:] + 564
    23  UIKit                               0x0000000105d24aaa -[UIView(Internal) _addSubview:positioned:relativeTo:] + 419
    24  UIKit                               0x0000000105cf2e37 -[UIWindow addRootViewControllerViewIfPossible] + 456
    25  UIKit                               0x0000000105cf3041 -[UIWindow _setHidden:forced:] + 247
    26  UIKit                               0x0000000105cff72c -[UIWindow makeKeyAndVisible] + 42
    27  UIKit                               0x0000000105caa061 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 2628
    28  UIKit                               0x0000000105cacd2c -[UIApplication _runWithMainScene:transitionContext:completion:] + 1350
    29  UIKit                               0x0000000105cabbf2 -[UIApplication workspaceDidEndTransaction:] + 179
    30  FrontBoardServices                  0x0000000108af32a3 __31-[FBSSerialQueue performAsync:]_block_invoke + 16
    31  CoreFoundation                      0x000000010535853c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    32  CoreFoundation                      0x000000010534e285 __CFRunLoopDoBlocks + 341
    33  CoreFoundation                      0x000000010534e045 __CFRunLoopRun + 2389
    34  CoreFoundation                      0x000000010534d486 CFRunLoopRunSpecific + 470
    35  UIKit                               0x0000000105cab669 -[UIApplication _run] + 413
    36  UIKit                               0x0000000105cae420 UIApplicationMain + 1282
    37  To Do List                          0x00000001052403ce top_level_code + 78
    38  To Do List                          0x000000010524040a main + 42
    39  libdyld.dylib                       0x0000000107740145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

Answer 1

您缺少必需的numberOfRowsInSection方法。要成为UITableViewDataSource，您需要实施numberOfRowsInSection和cellForRowAtIndexPath

无法将tableview添加到新选项卡式项目

1 个答案: