我在App Store中拥有我的第一个应用程序，但出现错误，无法在任何设备上复制。一位用户报告说，如果应用程序不崩溃，他将无法删除产品。我已经尝试了所有可以想到的复制方式，但没有运气。 iTunes Connect中没有崩溃报告，因此我注册了Crittercism。现在我知道有三个用户遇到了问题。
麻烦的是，即使有了崩溃日志，我仍然无法弄清应用程序崩溃的原因。当我删除一项内容时，即使是没有用户输入信息的新创建内容，它也永远不会崩溃。任何有关可以帮助我缩小问题范围的建议将不胜感激。该应用程序使用核心数据，并且该产品实体和其他实体的所有删除规则都设置为无效或级联。
崩溃日志表明崩溃的原因是“ NSInvalidArgumentException-deleteObject：需要一个非null参数”。这是回溯：
Reported Name Reason App Version Symbolicated
15-May-12 07:22:06 PM NSInvalidArgumentException
-deleteObject: requires a non-nil argument
0 CoreFoundation 0x317a888f __exceptionPreprocess + 162
1 libobjc.A.dylib 0x315f3259 objc_exception_throw + 32
2 CoreData 0x3325cf23 -[NSManagedObjectContext deleteObject:] + 386
3 OnShelf 0x000972e7 0x76000 + 135911
4 CoreFoundation 0x317023fd -[NSObject performSelector:withObject:withObject:] + 52
5 UIKit 0x319f0e07 -[UIApplication sendAction:to:from:forEvent:] + 62
6 UIKit 0x31ab65e7 -[UIBarButtonItem(UIInternal) _sendAction:withEvent:] + 118
7 CoreFoundation 0x317023fd -[NSObject performSelector:withObject:withObject:] + 52
8 UIKit 0x319f0e07 -[UIApplication sendAction:to:from:forEvent:] + 62
9 UIKit 0x319f0dc3 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 30
10 UIKit 0x319f0da1 -[UIControl sendAction:to:forEvent:] + 44
11 UIKit 0x319f0b11 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 492
12 UIKit 0x319f1449 -[UIControl touchesEnded:withEvent:] + 476
13 UIKit 0x319ef92b -[UIWindow _sendTouchesForEvent:] + 318
14 UIKit 0x319ef319 -[UIWindow sendEvent:] + 380
15 UIKit 0x319d5695 -[UIApplication sendEvent:] + 356
16 UIKit 0x319d4f3b _UIApplicationHandleEvent + 5826
17 GraphicsServices 0x32bd822b PurpleEventCallback + 882
18 CoreFoundation 0x3177c523 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 38
19 CoreFoundation 0x3177c4c5 __CFRunLoopDoSource1 + 140
20 CoreFoundation 0x3177b313 __CFRunLoopRun + 1370
21 CoreFoundation 0x316fe4a5 CFRunLoopRunSpecific + 300
22 CoreFoundation 0x316fe36d CFRunLoopRunInMode + 104
23 GraphicsServices 0x32bd7439 GSEventRunModal + 136
24 UIKit 0x31a03cd5 UIApplicationMain + 1080
25 OnShelf 0x00077207 0x76000 + 4615
26 OnShelf 0x000771bc 0x76000 + 4540
关于在UITableView中删除产品的代码，唯一不寻常的事情是它首先检查库存数量是否为零。如果不是，则会显示警报，询问用户是否确实要删除产品。一位联系我的用户确实告诉我，无论库存数量是否为零，他都崩溃了，因此崩溃似乎与所显示的警报无关。这是代码：
- (void)tableView:(UITableView *)tableView
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath
{
Product *product = [fetchedResultsController objectAtIndexPath:indexPath];
// Alert the user if the item is currently in stock
if ([product.details.quantity intValue] > 0) {
[self showAlert];
if (editingStyle == UITableViewCellEditingStyleDelete) {
lastIndexPath = indexPath;
toDelete = YES;
NSLog(@"Yes delete");
} else {
toDelete = NO;
}
} else {
// Delete the managed object.
NSManagedObjectContext *myContext = [fetchedResultsController managedObjectContext];
[myContext deleteObject:[fetchedResultsController objectAtIndexPath:indexPath]];
NSError *error;
if (![myContext save:&error]) {
// Update to handle the error appropriately.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
exit(-1); // Fail
}
}
}
#pragma mark - AlertView Delegate Methods
- (void)showAlert {
// open a alert with an OK and cancel button
UIAlertView *alert =[[UIAlertView alloc] initWithTitle: @"Product In Stock"
message: @"All product data will be deleted"
delegate: nil
cancelButtonTitle: @"Cancel"
otherButtonTitles:@"OK", nil];
[alert setDelegate: self];
[alert show];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
if (buttonIndex == 0) {
//do nothing
}
else
{
if( toDelete == YES)
{
// Delete the managed object.
NSManagedObjectContext *myContext = [fetchedResultsController managedObjectContext];
[myContext deleteObject:[fetchedResultsController objectAtIndexPath: lastIndexPath]];
NSError *error;
if (![myContext save:&error]) {
// Update to handle the error appropriately.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
exit(-1); // Fail
}
}
}
}
我正在使用Apple教程中的样板NSFetchedResultsController委托方法：
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath
forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *aTableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[aTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[aTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:(DatabaseCell *)[aTableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[aTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[aTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex
forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
[self.tableView endUpdates];
}
最佳答案
..回答晚了一点，但是最近才收到此错误消息“ NSInvalidArgumentException-deleteObject：要求一个非null的参数”。当我快速删除主从表视图中的项目并双击删除按钮时，发生了这种情况。解决我的问题的方法是在调用deleteObject之前检查indexPath是否为nil：
if (indexPath == nil) return;
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
关于ios - UITableView中的deleteObject错误，无法重复，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/10622014/