Question

当您单击Update按钮以更新UITableView时。

   .h
    NSArray *sortedArray;
    NSMutableArray *animals;

    .m
        -(void)update{
                [self checkAndCreateDatabase];
         [self readAnimalsFromDatabase];
         [self sort];
         [self.tableView reloadData];
        }


        - (void)sort{
         NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"distance" ascending:YES] autorelease];
         NSMutableArray *sortDescriptors = [NSMutableArray arrayWithObject:sortDescriptor];
         sortedArray = [animals sortedArrayUsingDescriptors:sortDescriptors];

        }

        - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
....
//This works but it uses the animals, unsorted array. 
//If I replace it with this: Animal *myAnimal = (Animal *)[sortedArray objectAtIndex:indexPath.row];, it will give the error1.

         Animal *myAnimal = (Animal *)[animals objectAtIndex:indexPath.row];
         NSString *temp = [NSString stringWithFormat:@"%@ - %@",myAnimal.distance, myAnimal.name];
         cell.textLabel.text = temp; 
         return cell;
        }

错误1：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[_NSIndexPathUniqueTreeNode objectAtIndex:]: unrecognized selector sent to instance 0x3d3feb0'

任何帮助都会很棒！谢谢。

Answer 1

您可能需要保留已排序的动物阵列

sortedArray = [[animals sortedArrayUsingDescriptors:sortDescriptors] retain];

线索是您的错误说[_NSIndexPathUniqueTreeNode objectAtIndex:]，但您希望sortedArray为NSArray，而不是_ NSIndexPathUniqueTreeNode。这告诉你sortedArray指向的对象已经改变了，这通常表明它已经被释放并且其他东西使用了内存。

萨姆

NSInvalidArgumentException UITableView

1 个答案: