UITableView Custom Section Header, duplicate issue

S-T-R-E-G-A picture S-T-R-E-G-A · Feb 28, 2010 · Viewed 8.3k times · Source

I am having trouble animating a custom UITableView section header.
The goal was to create collapsable sections.
When I tap on the custom header the first time it animates as expected, however every time after that it leaves a duplicate in the original location and animates another.

Image Example:

alt text alt text
My Custom Header:

- (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section { 
       UIView* customView = [[[UIView alloc]initWithFrame:CGRectMake(10.0, 0.0, 300.0, 44.0)]autorelease];
       customView.backgroundColor = [UIColor lightGrayColor];

       UILabel * headerLabel = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
            headerLabel.backgroundColor = [UIColor clearColor];
            headerLabel.opaque = NO;
            headerLabel.textColor = [UIColor darkGrayColor];
            headerLabel.font = [UIFont boldSystemFontOfSize:16];
            headerLabel.frame = CGRectMake(10, 7, 260.0, 44.0);
            headerLabel.textAlignment = UITextAlignmentCenter;
            NSDictionary *dictionary = [self.data objectAtIndex:section];
            headerLabel.text = [dictionary objectForKey:@"Title"];

            [customView addSubview:headerLabel];


            // add button to right corner of section
        UIButton* headerButton = [[UIButton alloc] initWithFrame:CGRectMake(10, 0, 320, 44)];
            headerButton.center = CGPointMake( 160.0, 22.0);
            headerButton.backgroundColor = [UIColor clearColor];
            headerButton.tag = section;
            [headerButton   addTarget:self action:@selector(expandSection:) forControlEvents:UIControlEventTouchUpInside];

            [customView addSubview:headerButton];

            return customView;
}

My Animation Method:

- (void) expandSection:(id)sender {

    if (expandedSection == [sender tag]) {
        expandedSection = -1;
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
    }else if (expandedSection == -1){
        expandedSection = [sender tag];
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
    }else{
        [self.tableView beginUpdates];  
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:expandedSection] withRowAnimation:UITableViewRowAnimationNone];
        expandedSection = [sender tag];
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
        [self.tableView endUpdates]; 

    }
    //[self.tableView reloadData];
}

I am not exactly sure whats going on, but the instances suggest that I need to dealoc something. I've tried a few things but I can't figure this out. Anyone help on this would be great!

Edit: I believe the problem is that reloadSections is causing the custom view to instance. I can't release the view because I need it as a reference to do the update for the animation. Any ideas on what I can do to fix this?

Answer

S-T-R-E-G-A picture S-T-R-E-G-A · Feb 28, 2010

Solution found.

The table needed to be reloaded before every change. This way the table is at the latest state before making any changes.

add [self.tableView reloadData]; as the fist entry in the "expandSection" method.

CODE:

- (void) expandSection:(id)sender {

  [self.tableView reloadData];

    if (expandedSection == [sender tag]) {
        expandedSection = -1;
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
    }else if (expandedSection == -1){
        expandedSection = [sender tag];
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
    }else{
        [self.tableView beginUpdates];  
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:expandedSection] withRowAnimation:UITableViewRowAnimationNone];
        expandedSection = [sender tag];
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[sender tag]] withRowAnimation:UITableViewRowAnimationNone];
        [self.tableView endUpdates]; 

    }
    //[self.tableView reloadData];
}