Resizing UITableView to fit content

Question

I am creating an app which will have a question in a UILabel and a multiple choice answers displayed in UITableView, each row showing a multiple choice. Questions and answers will vary, so I need this UITableView to be dynamic in height.

I would like to find a sizeToFit work around for the table. Where the table's frame is set to the height of all it's content.

Can anyone advise on how I can achieve this?

Answer 1

Swift 4.2 solution without KVO, DispatchQueue, setting constraints yourself. This solution is based on Gulz's answer.

1) Create a subclass of UITableView:

class IntrinsicTableView: UITableView {

    override var contentSize:CGSize {
        didSet {
            self.invalidateIntrinsicContentSize()
        }
    }

    override var intrinsicContentSize: CGSize {
        self.layoutIfNeeded()
        return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
    }

}

2) Add a UITableView to your layout and set constraints on all sides. Set the class of it to IntrinsicTableView.

3) You should see some errors, because Storyboard doesn't take our subclass' intrinsicContentSize into account. Fix this by opening the size inspector and overriding the intrinsicContentSize to a placeholder value. This is an override for design time. At runtime it will use the override in our IntrinsicTableView class

---

Update: Changed code for Swift 4.2. If you're using a prior version, use UIViewNoIntrinsicMetric instead of UIView.noIntrinsicMetric

Answer 2

Add an observer for the contentSize property on the table view, and adjust the frame size accordingly

[your_tableview addObserver:self forKeyPath:@"contentSize" options:0 context:NULL];

then in the callback:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
    {
         CGRect frame = your_tableview.frame;
         frame.size = your_tableview.contentSize;
         your_tableview.frame = frame;
    }

Hope this will help you.

Answer 3

Mimo's answer and Anooj VM 's answer both are awesome but there is a small problem if you have a large list, it's possible that the height of the frame will cutoff some of your cells.

So. I have modified the answer a little bit:

dispatch_async(dispatch_get_main_queue()) {
    //This code will run in the main thread:
    CGFloat newHeight=self.tableView.contentSize.height;
    CGFloat screenHeightPermissible=(self.view.bounds.size.height-self.tableView.frame.origin.y);
    if (newHeight>screenHeightPermissible)
    {
        //so that table view remains scrollable when 'newHeight'  exceeds the screen bounds
        newHeight=screenHeightPermissible;
    }

    CGRect frame = self.tableView.frame;
    frame.size.height = newHeight;
    self.tableView.frame = frame;
}