Question

I’m trying to make a subclass of UITableViewCell, which simply contains a UILabel Property “nameLabel” and a UILabel Property “statusLabel”.To dequeue the cells correctly, I implemented the cellForRowAtIndexPath: method like this:

PS: The text of statusLabel is from twitter API, so I have to send the size of it to [[UILabel alloc]initWithFrame:]

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    static NSString *CellIdentifier = @"StatusCellView";
    StatusCellView *cell = [tableView dequeueReusableCellWithIdentifier:
                        CellIdentifier];
    if (cell == nil) {
        cell = [[StatusCellView alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }
    for (UIView *subView in cell.contentView.subviews) {
        [subView removeFromSuperview];
    }
    if (![cell viewWithTag:kNameLabelTag]) {
        //init the nameLabel and [cell.contentView addsubview:nameLabel]
    }
    if (![cell viewWithTag:kStatusLabelTag]) {
        //init the statusLabel and [cell.contentView addsubview:statusLabel]
    }

    return cell;

As you can see, this works well when the data is not so large. But my question is :

• I think removing and adding the subview repeatedly will make the performance bad. It’s a rude way…
• I can implement the same function without subclassing UITableViewCell. Is there any way to make use of the subclass?

Answer 1

I don’t really understand why you have to remove them…this seems like a perfectly reasonable way of doing it:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
static NSString *CellIdentifier = @"StatusCellView";
StatusCellView *cell = [tableView dequeueReusableCellWithIdentifier:
                    CellIdentifier];
if (cell == nil) {
    cell = [[StatusCellView alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    //init the nameLabel and [cell.contentView addSubview:nameLabel];
    //init the statusLabel and [cell.contentView addsubview:statusLabel]
}
else {
    UILabel *nameLabel = [cell viewithTag:kStatusLabelTag];
    nameLabel.frame = newFrame;
    nameLabel.text = newText
    //etc, etc, etc
}
return cell;