Question

i went table view change content depend on SegmentIndex

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];     
    }

    // Set up the cell
    book *bok = (book *)[self.booktable objectAtIndex:indexPath.row];

    NSArray *rowoftitle = [NSArray arrayWithObjects:bok.book_title, nil];
    NSArray *rowofauth = [NSArray arrayWithObjects:bok.author_name, nil];
    NSArray *rowofpub = [NSArray arrayWithObjects:bok.pub_name, nil];

    //[cell setText:bok.book_title];
    [tableView beginUpdates];

    switch (segControl.selectedSegmentIndex) 
    {
        case 0:
        [tableView insertRowsAtIndexPaths:rowoftitle withRowAnimation:UITableViewRowAnimationTop];

        //cell.textLabel.text =bok.book_title; 
        break;

    case 1:
        [tableView insertRowsAtIndexPaths:rowofauth withRowAnimation:UITableViewRowAnimationTop];


        //[libraryTV reloadData];
        //cell.textLabel.text =bok.author_name;
        break;
    case 2:
        [tableView insertRowsAtIndexPaths:rowofpub withRowAnimation:UITableViewRowAnimationTop];

        //cell.textLabel.text =bok.pub_name;
        break;

    default:
        break;          
}

    [tableView endUpdates];
    //return cell;  
}

but when run it the expiation is happen :

‘NSInvalidArgumentException’, reason: ‘-[NSCFString row]: unrecognized
selector sent to instance 0x5d84f80

how resolve it.

Answer 1

One solution could be:

You will need to use a common datasource (in this code I am using dataSourceArray for this purpose, you will need to declare it in header file and alloc/init in viewDidLoad method.), which will be updated on changing the segment.
It will have following method.(for segment change event)

-(void)segmentSelected:(UISegmentedControl *)sender
{
    switch (sender.selectedSegmentIndex)
    {
        case 0:
            [self loadTitles];
            break;
        case 1:
            [self loadAuthors];
            break;
        case 2:
            [self loadPublishers];
            break;
        default:
            break;
    }
}




- (void) loadTitles
{
    [self.dataSourceArray removeAllObjects];
    for (Book *book in self.booktable) 
    {
        [dataSourceArray addObject:book.book_title];
    }
    [<yourTableViewVariable> reloadData];
}

Similarly code for other methods loadAuthors and loadPublishers.

Now your numberOfRowsInSection method will be:

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

and cellForRowAtIndexPath will be:

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];     
    }

    // Set up the cell
    cell.textLabel.text = [dataSourceArray objectAtIndex:indexPath.row];
    return cell;  
}

Thanks