IOS adds constraint to table section header

I am working with a grouped table and setting the header in the sections using the tableView: viewForHeaderInSection: method and setting the height using tableView: heightForHeaderInSection :.

I created a view and put a shortcut in it like this:

- (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {


    // Create a custom title view.
    UIView *ctv;
    UILabel *titleLabel;

    // Set the name.
    {...} // Code not relevant

    // If an iPhone.
    if ([Config isPhone]) {
        ctv = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
        titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 14, 320, 36)];
    }
    // If an iPad
    else {
        ctv = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 768, 75)];
        titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 20, 544, 55)];
    }

    // Config the label.
    {...} // Code not relevant

    // Center the items.
    ctv.center = CGPointMake(tableView.center.x, ctv.center.y);
    titleLabel.center = ctv.center;

    // Add the label to the container view.
    [ctv addSubview:titleLabel];

    // Return the custom title view.
    return ctv;


}

      

        
        
        
      

    

This all works great until you rotate the screen. Off position. I understand that this is because the viewpoint is centered while it is in a different orientation, resulting in the center being calculated no longer being correct. The solution should be to add a constraint. I tried to add the constraint below:

NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(ctv);
NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|[ctv]|"
                         options:0
                         metrics:nil
                         views:viewsDictionary
                       ];
[tableView addConstraints:constraints];

      

        
        
        
      

    

But when I do this while trying to use the method below, I realize that there is no parent view associated with it, which makes full sense, because it is not technically being added to the view. So I thought I'd try to add a constraint like this:

NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:ctv
                                     attribute:NSLayoutAttributeCenterX
                                     relatedBy:NSLayoutRelationEqual
                                        toItem:tableView
                                     attribute:NSLayoutAttributeCenterX
                                    multiplier:1.0
                                      constant:0
                                      ];
[tableView addConstraint:constraint];

      

        
        
        
      

    

But these are also mistakes. I tried to switch the tableView variables to the global table property, but it gives the same results. I also tried to figure out how to add a constraint in the view, loaded the method, but it failed as I couldn't figure out how to get back to the table section headers from the table object. The last thought I had was to set the width of the table in the constraint and set it to the center of the entire table. This process worked, but now I have an ugly scroll in the middle of my application when in landscape orientation. So the question is, where / how can I access the individual section headers after loading them in order to add this constraint? I'm still pretty new to Objective-C, so any help is appreciated.

***** NEW CODE BASED ON rdelmar SUGGESTION ****

- (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    UIView *ctv = [tableView dequeueReusableHeaderFooterViewWithIdentifier:@"groupHeader"];
    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 20, 544, 55)];
    [titleLabel setTranslatesAutoresizingMaskIntoConstraints: NO];
    NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:ctv
                                        attribute:NSLayoutAttributeCenterX
                                        relatedBy:0
                                          toItem:titleLabel
                                        attribute:NSLayoutAttributeCenterX
                                       multiplier:1.0
                                         constant:0
                                      ];
    [ctv addConstraints:@[constraint]];
    titleLabel.text = @"string";
    [ctv addSubview:titleLabel];
    return ctv;
}

      

        
        
        
      

    

But as I mentioned, it gives me the error "Constraint must contain the first element of the layout".