How to resize a tableHeaderView of a UITableView?

Solution 1:

FYI: I've gotten this to work by modifying the tableHeaderView and re-setting it. In this case, i'm adjusting the size of the tableHeaderView when the UIWebView subview has finished loading.

[webView sizeToFit];
CGRect newFrame = headerView.frame;
newFrame.size.height = newFrame.size.height + webView.frame.size.height;
headerView.frame = newFrame;
[self.tableView setTableHeaderView:headerView];

Solution 2:

This answer is old and apparently doesn't work on iOS 7 and above.

I ran into the same problem, and I also wanted the changes to animate, so I made a subclass of UIView for my header view and added these methods:

- (void)adjustTableHeaderHeight:(NSUInteger)newHeight{
    NSUInteger oldHeight = self.frame.size.height;
    NSInteger originChange = oldHeight - newHeight;

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:1.0f];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];

    self.frame = CGRectMake(self.frame.origin.x, 
                        self.frame.origin.y, 
                        self.frame.size.width, 
                        newHeight);

    for (UIView *view in [(UITableView *)self.superview subviews]) {
        if ([view isKindOfClass:[self class]]) {
            continue;
        }
        view.frame = CGRectMake(view.frame.origin.x, 
                            view.frame.origin.y - originChange, 
                            view.frame.size.width, 
                            view.frame.size.height);
    }

    [UIView commitAnimations];
}

- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context{
    [(UITableView *)self.superview setTableHeaderView:self];
}

This essentially animates all the subviews of the UITableView that aren't the same class type as the calling class. At the end of the animation, it calls setTableHeaderView on the superview (the UITableView) – without this the UITableView contents will jump back the next time the user scrolls. The only limitation I've found on this so far is if the user attempts to scroll the UITableView while the animation is taking place, the scrolling will animate as if the header view hasn't been resized (not a big deal if the animation is quick).

Solution 3:

If you want to conditionally animate the changes you can do the following:

- (void) showHeader:(BOOL)show animated:(BOOL)animated{

    CGRect closedFrame = CGRectMake(0, 0, self.view.frame.size.width, 0);
    CGRect newFrame = show?self.initialFrame:closedFrame;

    if(animated){
        // The UIView animation block handles the animation of our header view
        [UIView beginAnimations:nil context:nil];
        [UIView setAnimationDuration:0.3];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];

        // beginUpdates and endUpdates trigger the animation of our cells
        [self.tableView beginUpdates];
    }

    self.headerView.frame = newFrame;
    [self.tableView setTableHeaderView:self.headerView];

    if(animated){
        [self.tableView endUpdates];
        [UIView commitAnimations];
    }
}

Please note that the animation is two-folded:

1. The animation of the cells below the tableHeaderView. This is done using beginUpdates and endUpdates
2. The animation of the actual header view. This is done using a UIView animation block.

In order to synchronize those two animations the animationCurve has to be set to UIViewAnimationCurveEaseInOut and the duration to 0.3, which seems to be what the UITableView uses for it's animation.

Update

I created an Xcode project on gihub, which does this. Check out the project ResizeTableHeaderViewAnimated in besi/ios-quickies

Solution 4:

I think it should work if you just set the height of myHeaderView like so:

CGRect newFrame = myHeaderView.frame;
newFrame.size.height = newFrame.size.height + 100;
myHeaderView.frame = newFrame;

self.tableView.tableHeaderView = myHeaderView;

Solution 5:

Used @garrettmoon solution above until iOS 7.
Here's an updated solution based on @garrettmoon's:

- (void)adjustTableHeaderHeight:(NSUInteger)newHeight animated:(BOOL)animated {

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:[CATransaction animationDuration]];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];

    self.frame = CGRectMake(self.frame.origin.x,
                        self.frame.origin.y,
                        self.frame.size.width,
                        newHeight);

    [(UITableView *)self.superview setTableHeaderView:self];

    [UIView commitAnimations];
}

- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context{
    [(UITableView *)self.superview setTableHeaderView:self];
}