UITableView -headerViewForSection returns (null)

ios, objective-c, uitableview

Solution

METHOD 1:

Ok, after some trial and error, I finally solved my own dilemma. I did the `headerView` just as I would do a cell.

For a cell we would take `UITableViewCell` and use `dequeueReusableCellWithIdentifier` while... For a Header/Footer, we will take `UITableViewHeaderFooterView` and use the `dequeueReusableHeaderFooterViewWithIdentifier` method.

The rest is pretty much the same concept as a cell.

Prerequisites:

- Set header height to 40

- Set number of sections to 2 or more

- Set number of rows per section to be atleast 1

- iOS6+ (`UITableViewHeaderFooterView` won't work with iOS5 and below)

First Approach:

Creating and using the default `UITableViewHeaderFooterView` within `-viewForHeaderInSection:` method:

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    static NSString *HeaderIdentifier = @"header";

    UITableViewHeaderFooterView *myHeader = [tableView dequeueReusableHeaderFooterViewWithIdentifier:HeaderIdentifier];
    if(!myHeader) {
        myHeader = [[UITableViewHeaderFooterView alloc] initWithReuseIdentifier:HeaderIdentifier];
    }

    UIButton *btnUp = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [btnUp setTag:101];
    [btnUp setTitle:@"-" forState:UIControlStateNormal];
    [btnUp setFrame:CGRectMake(tableView.frame.size.width - 35, 5, 30, 30)];
    [myHeader addSubview:btnUp];

    [myHeader.textLabel setText:[NSString stringWithFormat:@"Section: %d",section]];

    [myHeader setFrame:CGRectMake(0, 0, tableView.frame.size.width, 50)];
    return myHeader;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewHeaderFooterView *theHeaderView = [tableView headerViewForSection:indexPath.section];
    NSLog(@"%@",theHeaderView); // -- great! ... not (null) anymore

    UIButton *theButton = (UIButton *)[theHeaderView viewWithTag:101];
    [theButton setTitle:@"+" forState:UIControlStateNormal];
}

Second Approach:

Using a custom `UITableViewHeaderFooterView` subclass:

- Created a `UITableViewHeaderFooterView` subclass and named it `CustomHeaderView`

- Created a View interface nib file for the class

- In the xib, selected the View & in it's Identity Inspector

- Specified the Custom Class as `CustomHeaderView`

- Made properties, synthesized and connected them in the xib

- `@property (strong, nonatomic) IBOutlet UILabel *lblSomething;`

- `@property (strong, nonatomic) IBOutlet UIButton *btnSomething;`

Modified the `-viewForHeaderInSection:` & `-didSelectRowAtIndexPath:` as:

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    static NSString *HeaderIdentifier = @"header";

    CustomHeaderView *myHeader = [tableView dequeueReusableHeaderFooterViewWithIdentifier:HeaderIdentifier];
    if(!myHeader) {
    //    [tableView registerClass:[CustomHeaderView class] forHeaderFooterViewReuseIdentifier:HeaderIdentifier];
        myHeader = [[[NSBundle mainBundle] loadNibNamed:@"CustomHeaderView"
                                                  owner:self
                                                options:nil] objectAtIndex:0];
    }

    [myHeader.btnSomething setTitle:@"-" forState:UIControlStateNormal];
    [myHeader.lblSomething setText:[NSString stringWithFormat:@"Section: %d",section]];

    return myHeader;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomHeaderView *theHeaderView = (CustomHeaderView*)[tableView headerViewForSection:indexPath.section];
    NSLog(@"%@",theHeaderView);

    [theHeaderView.lblSomething setAlpha:theHeaderView.lblSomething.alpha-0.1];
    [theHeaderView.btnSomething setTitle:@"+" forState:UIControlStateNormal];
}

PS: The issue with `UITableViewHeaderFooterView` is that it is iOS6+ only and if, for any reason, your header is/must be a `UIView`, then see the next method

METHOD 2:

Using a simple `UIView`:

-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *vwHeader = [[UIView alloc] init];
    [vwHeader setTag:200 + section]; //[1] first method

    switch (section) {
        case 0:
            [vwHeader setBackgroundColor:[UIColor greenColor]];
            break;
        case 1:
            [vwHeader setBackgroundColor:[UIColor redColor]];
            break;
        default:
            break;
    }

    UILabel *lblTitle = [[UILabel alloc] init];
    [lblTitle setFrame:CGRectMake(10, 0, 100, 30)];
    [lblTitle setTag:100 + section]; //[2] alternative method
    [lblTitle setBackgroundColor:[UIColor clearColor]];
    [lblTitle setText:[NSString stringWithFormat:@"Section: %d",section]];

    [vwHeader addSubview:lblTitle];
    return vwHeader;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIView *vwTest = [self.tableView viewWithTag:200 + indexPath.section]; //[1]
    NSLog(@"[1] : %@",vwTest);

    //or

    UILabel *lblTest = (UILabel *)[self.tableView viewWithTag:100 + indexPath.section]; //[2]
    NSLog(@"%@",lblTest.text);
    UIView *vwTestForSuperview = lblTest.superview;
    NSLog(@"[2] : %@",vwTestForSuperview);
}

PS: I know this code doesn't serve any great purpose but this is just an example for others.

Problem

Original source

Related problems

• uitableview headerViewForSection: always returns nil