XCode 6问题-dequeueReusableCellWithIdentifier不返回自定义单元格高度

Question

I have a UITableViewController with 2 prototype cells with custom heights - one has a height of 187 points and the other has a height of 140 points. The tableview's default row height is ser to 187.

My cellForRowAtIndexPath looks like this:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
    if (indexPath.section == 0) {
        MyListingCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MyListingCell"];
        [cell initWithListing:[self.listings objectAtIndex:indexPath.row]];
        return cell;
    } else {
        return [tableView dequeueReusableCellWithIdentifier:@"AddMyListingCell"];
    }
}

and I have a matching heightForRowAtIndexPath which looks like this:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath 
{
    if (indexPath.section == 0) {
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MyListingCell"];
        return cell.frame.size.height;
    } else {

        //if no listings exist, make the cell full-screen height
        if (self.listings.count == 0) {   
            return tableView.frame.size.height;
        } else {
            UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"AddMyListingCell"];
            return cell.frame.size.height;
        }
    }
}

When I run the code, the cell heights come out correctly. 187 and 140 respectively.

However, I would like to change the size of the larger cell to 213 points. To do this I change the custom tablecell height to 213. The problem is that when I run the code (using XCode 6) the table cells still come out as height 187.

I tried changing the default tableview rowheight property, also to 213. However I still get 187. In fact, when I look at the storyboard (as text) there is no mention of 187 anywhere. But it seems that XCode is remembering the previous value.

I have tried cleaning, deep cleaning, restarting xcode, deleteing the app from my phone, and deleting my debug products. I can't get it to forget the 187.

Could this be a bug in XCode 6? In XCode 5 this does not happen (proven). Custom cell heights have been working fine in XCode 5 but this problem has arisen the very day after I install XCode 6.

Can anyone help with some advice on things to try, or some confirmation that I'm not going crazy.

Answer 1

heightForRowAtIndexPath is called BEFORE cellForRowAtIndexPath , so you can never use it to try to reference a cell and get the height. Look at the following code with the following log lines and result:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"CELL");
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];
    }

    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"HEIGHT");
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    NSLog(@"%@", cell);
    return cell.frame.size.height;
}

That results in:

2014-09-23 09:55:05.114 NewTesting[54040:60b] HEIGHT
2014-09-23 09:55:05.114 NewTesting[54040:60b] (null)
2014-09-23 09:55:05.115 NewTesting[54040:60b] HEIGHT
2014-09-23 09:55:05.115 NewTesting[54040:60b] (null)
2014-09-23 09:55:05.115 NewTesting[54040:60b] HEIGHT
2014-09-23 09:55:05.116 NewTesting[54040:60b] (null)
2014-09-23 09:55:05.116 NewTesting[54040:60b] HEIGHT
2014-09-23 09:55:05.116 NewTesting[54040:60b] (null)
2014-09-23 09:55:05.117 NewTesting[54040:60b] CELL
2014-09-23 09:55:05.118 NewTesting[54040:60b] CELL
2014-09-23 09:55:05.119 NewTesting[54040:60b] CELL
2014-09-23 09:55:05.120 NewTesting[54040:60b] CELL

With that in mind the method you're using would never work.

Have you tried something more simple, like the following (although I would personally use constants)

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return indexPath.section == 0 ? 213 : 140;
}

That is assuming all the cells in the first section are 213 tall and any other section 140 tall, which may be incorrect.

Ultimately, I think the best way to do what you want to do is to essentially ask your data source what type of cell should exist at that given indexPath , and therefore how tall the cell should be.