viewDidAppear for UITableViewCell

Question

I usually use viewDidAppear method to do some UI stuff on the view after it finished appearing and I used this method in various situations were it was very useful, however, I need to do some UI changes on a UITableViewCell after it finished appearing, is there any available method in the SDK that does a similar job like viewDidAppear but for UITableViewCell ?

p.s. willDisplayCell did not work in my case, I need something like didDisplayCell if it really exists.

Answer 1

The method viewDidLoad is related to UIViewController and its subclasses, so we cannot use this in UITableViewCell, which is a UIView subclass. The solution I used in one of my app is to override the layoutSubViews method of UITableViewCell, and I delayed the action for some time as below.

- (void)layoutSubViews
{
     [super layoutSubviews];

     [self performSelector:@selector(myMethod) withObject:nil afterDelay:1.0];
}

Answer 2

The UITableViewDelegate has these functions:

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)

func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath)

The cell itself does not have callbacks for this.

Answer 3

You can use didMoveToSuperview and do your cell updates there

override func didMoveToSuperview() {
    super.didMoveToSuperview()

    if superview != nil {
        // Update the cell
    }
}

In case you need something faster, use willDisplayCell

func tableView(_ tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
    // Update the cell
}

Answer 4

If you need to respond to changes to the cell's frame and adjust the layout, you need to implement -layoutSubviews in the cell class. Remember to call [super layoutSubviews].