如何将项目添加到UITableView？

Question

我正在尝试UITableView使用按钮添加项目,这是我的代码:

在viewDidLoad:repository = [[NSMutableArray alloc] initWithObjects: nil];

//ADD ITEM TO LIST
                [repository addObject:repo]; //repository is a NSMutableArray
                NSIndexPath *indexPath = [NSIndexPath indexPathForRow:([repository count]-1) inSection:0];
                NSLog(@"Indexpath to add row ----> %ld", (long)indexPath.row);
                [self.tableView beginUpdates];
                [self.tableView insertRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationBottom];
                [self.tableView endUpdates];

它现在将项目广告到列表中,但前提是它中已有一个Cell

UITableViewController like i configured here: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSLog(@"NSMutableArray count in \"numbersOfRowsInSection\" ----> %lu", (unsigned long)[repository count]);

    return [repository count] + 1;

}

这是我的日志:

Indexpath to add row ----> <NSIndexPath: 0x10d9499a0> {length = 2, path = 0 - 18446744073709551615} //This is "NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[repository count] - 1 inSection:0];" 
2013-10-22 14:48:42.214 ApplicationName[41213:a0b] NSMutableArray count in "numbersOfRowsInSection" ----> 0 //This is the NSInteger returned in - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;
2013-10-22 14:48:42.217 ApplicationName[41213:a0b] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-2903.2/UITableView.m:1330
2013-10-22 14:48:42.236 ApplicationName[41213:a0b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (0) must be equal to the number of rows contained in that section before the update (0), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000101cdf795 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x00000001019bb991 objc_exception_throw + 43
    2   CoreFoundation                      0x0000000101cdf61a +[NSException raise:format:arguments:] + 106
    3   Foundation                          0x0000000101558bf9 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 189
    4   UIKit                               0x00000001006d51db -[UITableView _endCellAnimationsWithContext:] + 11410
    5   ApplicationName                           0x0000000100009b5d -[RepositoryViewController alertView:clickedButtonAtIndex:] + 829
    6   UIKit                               0x0000000100b1dbd8 -[_UIModalItemsCoordinator _notifyDelegateModalItem:tappedButtonAtIndex:] + 151
    7   UIKit                               0x0000000100707629 -[_UIModalItemAlertContentView tableView:didSelectRowAtIndexPath:] + 364
    8   UIKit                               0x00000001006e3d36 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 1312
    9   UIKit                               0x00000001006e3e5f -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 221
    10  UIKit                               0x000000010063b0d2 _applyBlockToCFArrayCopiedToStack + 316
    11  UIKit                               0x000000010063af50 _afterCACommitHandler + 460
    12  CoreFoundation                      0x0000000101caaf97 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    13  CoreFoundation                      0x0000000101caaf07 __CFRunLoopDoObservers + 391
    14  CoreFoundation                      0x0000000101c8a672 __CFRunLoopRun + 946
    15  CoreFoundation                      0x0000000101c89ed3 CFRunLoopRunSpecific + 467
    16  GraphicsServices                    0x0000000102efa3a4 GSEventRunModal + 161
    17  UIKit                               0x0000000100623a63 UIApplicationMain + 1010
    18  ApplicationName                           0x000000010000aae3 main + 115
    19  libdyld.dylib                       0x00000001067fd7e1 start + 0
    20  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Answer 1

好吧,我偶然发现了这个问题,我正在使用swift,所以我想在这里发布我的代码:

func addOneMoreRow(){
  rowsCount++
  let indexPath = NSIndexPath(forRow: rowsCount - 1, inSection: 0)
  tableView.beginUpdates()
  tableView.insertRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Bottom)
  tableView.endUpdates()
} 

Answer 2

更新:

首先,您的numberOfRowsInSection:方法应返回代表您的数据源的确切数量行.在这种情况下,存储库:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [repository count];
}

其次,每当用户按下按钮添加新单元格时,首先需要向数据源添加项目,然后需要插入单元格本身.

- (void)didPressButton
{
   [repository addObject:repo]; //repository is a NSMutableArray
   NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[repository indexOfObject:repo] inSection:0];
   [self.tableView beginUpdates];
   [self.tableView
insertRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationBottom];
   [self.tableView endUpdates];
}

就这么简单.