Question

所以，我正在调试我正在构建的应用程序并使用描述方法来帮助我找到问题。但不是将应用程序作为字符串提供给我，而是打印出括号。请帮忙！

以下是代码：

- (void)viewDidLoad {
[super viewDidLoad];

reminders = [[NSMutableArray alloc] init];
currentTitle = [[NSMutableString alloc] init];
currentDate = [[NSMutableString alloc] init];
currentSummary = [[
                NSMutableString alloc] init];
currentLink = [[NSMutableString alloc] init];

NSLog(@"IT'S HERE %@", [reminders description]);}

...

和错误：

[Session started at 2010-10-04 22:15:16 -0400.]
2010-10-04 22:15:17.434 Reminders[5824:207] ******* Accessibility Status Changed: On
2010-10-04 22:15:17.464 Reminders[5824:207] ********** Loading AX for: com.yourcompany.Reminders ************
2010-10-04 22:15:17.506 Reminders[5824:207] IT'S HERE (
)
2010-10-04 22:15:17.510 Reminders[5824:207] Hello
2010-10-04 22:15:17.512 Reminders[5824:207] (
)
2010-10-04 22:15:17.514 Reminders[5824:207] PVC: <UITableView: 0x602d600; frame = (0 20; 320 460); clipsToBounds = YES; opaque = NO; autoresize = W+H; layer = <CALayer: 0x5f3f3b0>; contentOffset: {0, 0}>
2010-10-04 22:15:17.514 Reminders[5824:207] It's here
2010-10-04 22:15:17.515 Reminders[5824:207] Loaded
2010-10-04 22:15:17.520 Reminders[5824:207] -[__NSCFArray name]: unrecognized selector sent to instance 0x6a4b640
2010-10-04 22:15:17.523 Reminders[5824:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFArray name]: unrecognized selector sent to instance 0x6a4b640'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x0248bb99 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x025db40e objc_exception_throw + 47
    2   CoreFoundation                      0x0248d6ab -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x023fd2b6 ___forwarding___ + 966
    4   CoreFoundation                      0x023fce72 _CF_forwarding_prep_0 + 50
    5   Reminders                           0x00003aa9 -[RootViewController tableView:cellForRowAtIndexPath:] + 300
    6   UIKit                               0x00090d6f -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:withIndexPath:] + 619
    7   UIKit                               0x00086e02 -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:] + 75
    8   UIKit                               0x0009b774 -[UITableView(_UITableViewPrivate) _updateVisibleCellsNow:] + 1561
    9   UIKit                               0x000937ec -[UITableView layoutSubviews] + 242
    10  QuartzCore                          0x03f60481 -[CALayer layoutSublayers] + 177
    11  QuartzCore                          0x03f601b1 CALayerLayoutIfNeeded + 220
    12  QuartzCore                          0x03f592e0 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 302
    13  QuartzCore                          0x03f59040 _ZN2CA11Transaction6commitEv + 292
    14  UIKit                               0x0002204e -[UIApplication _reportAppLaunchFinished] + 39
    15  UIKit                               0x00022477 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 545
    16  UIKit                               0x0002c3ec -[UIApplication handleEvent:withNewEvent:] + 1958
    17  UIKit                               0x00024b3c -[UIApplication sendEvent:] + 71
    18  UIKit                               0x000299bf _UIApplicationHandleEvent + 7672
    19  GraphicsServices                    0x026fa822 PurpleEventCallback + 1550
    20  CoreFoundation                      0x0246cff4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    21  CoreFoundation                      0x023cd807 __CFRunLoopDoSource1 + 215
    22  CoreFoundation                      0x023caa93 __CFRunLoopRun + 979
    23  CoreFoundation                      0x023ca350 CFRunLoopRunSpecific + 208
    24  CoreFoundation                      0x023ca271 CFRunLoopRunInMode + 97
    25  UIKit                               0x00021c6d -[UIApplication _run] + 625
    26  UIKit                               0x0002daf2 UIApplicationMain + 1160
    27  Reminders                           0x00002078 main + 102
    28  Reminders                           0x00002009 start + 53
)
terminate called after throwing an instance of 'NSException'

以下是您要求使用fluchtpunkt的方法

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"cell";

    cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    // Configure the cell.

    Reminder *theReminder = [reminders objectAtIndex:indexPath.row];

    cell.textLabel.text = theReminder.name;

    return cell;

    }

Answer 1

如果我NSLog一个空数组，那些括号是我期望的输出这绝对是正确的。

引发异常是因为您尝试在NS（Mutable）数组上调用name方法。并且数组不响应名称。

要查找此异常的原因，请在RootViewController

中发布此方法的代码

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

NSObject的'描述'方法给出括号作为输出？

1 个答案: