帮助解决异常的XCode

Question

我试图运行下面的代码：

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

    static NSString *CellIdentifier = @"CellIdentifier"; 
    GradeToolAppDelegate * appDelegate = [UIApplication sharedApplication].delegate; 
    appDelegate = [UIApplication sharedApplication].delegate; 
    // Dequeue or create a cell of the appropriate type. 
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 
    if (cell == nil) { 
     cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; 
     cell.accessoryType = UITableViewCellAccessoryNone; 
    } 
    NSLog(@"Array Count: %d", [appDelegate.modules count]); 
    // Configure the cell. 
    //cell.textLabel.text = [NSString stringWithFormat:@"Row %d", indexPath.row]; 
    //Module * aModule = [appDelegate.modules objectAtIndex:indexPath.row]; 
    //cell.textLabel.text = aModule.moduleTitle; 
    return cell; 
} 

，但它只是崩溃的应用程序有：

2011-05-20 15:38:09.256 GradeTool[3994:207] -[GradeToolAppDelegate modules]: unrecognized selector sent to instance 0x5523f80 
2011-05-20 15:38:09.258 GradeTool[3994:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[GradeToolAppDelegate modules]: unrecognized selector sent to instance 0x5523f80' 
*** Call stack at first throw: 
(
    0 CoreFoundation      0x00eebbe9 __exceptionPreprocess + 185 
    1 libobjc.A.dylib      0x00ce05c2 objc_exception_throw + 47 
    2 CoreFoundation      0x00eed6fb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187 
    3 CoreFoundation      0x00e5d366 ___forwarding___ + 966 
    4 CoreFoundation      0x00e5cf22 _CF_forwarding_prep_0 + 50 
    5 GradeTool       0x000037ff -[RootViewController tableView:cellForRowAtIndexPath:] + 322 
    6 UIKit        0x003367fa -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:withIndexPath:] + 634 
    7 UIKit        0x0032c77f -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:] + 75 
    8 UIKit        0x00341450 -[UITableView(_UITableViewPrivate) _updateVisibleCellsNow:] + 1561 
    9 UIKit        0x00339538 -[UITableView layoutSubviews] + 242 
    10 QuartzCore       0x01ff8451 -[CALayer layoutSublayers] + 181 
    11 QuartzCore       0x01ff817c CALayerLayoutIfNeeded + 220 
    12 QuartzCore       0x01ff137c _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 310 
    13 QuartzCore       0x01ff10d0 _ZN2CA11Transaction6commitEv + 292 
    14 UIKit        0x002c519f -[UIApplication _reportAppLaunchFinished] + 39 
    15 UIKit        0x002c5659 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 690 
    16 UIKit        0x002cfdb2 -[UIApplication handleEvent:withNewEvent:] + 1533 
    17 UIKit        0x002c8202 -[UIApplication sendEvent:] + 71 
    18 UIKit        0x002cd732 _UIApplicationHandleEvent + 7576 
    19 GraphicsServices     0x01a70a36 PurpleEventCallback + 1550 
    20 CoreFoundation      0x00ecd064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52 
    21 CoreFoundation      0x00e2d6f7 __CFRunLoopDoSource1 + 215 
    22 CoreFoundation      0x00e2a983 __CFRunLoopRun + 979 
    23 CoreFoundation      0x00e2a240 CFRunLoopRunSpecific + 208 
    24 CoreFoundation      0x00e2a161 CFRunLoopRunInMode + 97 
    25 UIKit        0x002c4fa8 -[UIApplication _run] + 636 
    26 UIKit        0x002d142e UIApplicationMain + 1160 
    27 GradeTool       0x00002960 main + 102 
    28 GradeTool       0x000028f1 start + 53 
) 
terminate called after throwing an instance of 'NSException' 

的GradeToolAppDelegate * appDelegate = [UIApplication sharedApplication].delegate;似乎是主要问题之一，当运行NSLog(@"Array Count: %d", [appDelegate.modules count]);导致异常

任何人都可以帮助我在这里我做错了什么。

谢谢。

Answer 1

您的GradeToolAppDelegate没有定义modules方法。看到你通过点符号引用，我假设你忘了：定义属性和/或综合属性。