How to add corner radius and a background to a whole section including its header and cells in UI Table View

Question

How do I add corner radius and background to both the section header and its cell together like in the iOS weather app?

My table view data source and delegate-

extension HomeViewController: UITableViewDataSource, UITableViewDelegate {
    
    func numberOfSections(in tableView: UITableView) -> Int {
        10
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        1
    }
    
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        
        guard let cell = tableView.dequeueReusableCell(withIdentifier: HourlyForecastViewTableViewCell.identifier) else { return UITableViewCell() }
        cell.layer.backgroundColor = UIColor.blue.cgColor
        return cell
        
    }
    
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        200
    }
    
    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        return HourlyForecastHeaderView()
    }
    
    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        return 40
    }
}

Answer 1

You can tryout this below code, here I just explained how to use UIRectCorner to apply corner radius to the specific edge.

extension ViewController: UITableViewDataSource {
    func numberOfSections(in tableView: UITableView) -> Int {
        2
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        5
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let kCellId = "kCellId"
        var lCell = tableView.dequeueReusableCell(withIdentifier: kCellId)
        if lCell == nil {
            lCell = UITableViewCell(style: .default, reuseIdentifier: kCellId)
            lCell?.textLabel?.text = "Row - \(indexPath.row)"
        }
        lCell?.backgroundColor = .orange
        return lCell!
    }
    
    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        let kHeaderId = "kHeaderId"
        var header = tableView.dequeueReusableHeaderFooterView(withIdentifier: kHeaderId)
        if header == nil {
            header = HeaderView(reuseIdentifier: kHeaderId)
            header?.frame = CGRect(origin: .zero, size: CGSize(width: tableView.bounds.size.width, height: 35))
            header?.tintColor = .orange
            
            let titleLabel = UILabel()
            titleLabel.text = "Section - \(section)"
            titleLabel.sizeToFit()
            titleLabel.frame = CGRect(origin: CGPoint(x: 20, y: 0), size: CGSize(width: tableView.bounds.size.width-20, height: 35))
            header?.addSubview(titleLabel)
        }
        return header
    }
    
    func tableView(_ tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
        view.applyCorners(to: [.topLeft, .topRight], with: view.bounds)
    }
    
    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
        let isLastCell = tableView.numberOfRows(inSection: indexPath.section)-1 == indexPath.row
        if isLastCell {
            cell.applyCorners(to: [.bottomLeft, .bottomRight], with: cell.bounds)
        }else{
            cell.noCorners()
        }

    }
}

extension ViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        50
    }
    
    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        35
    }
}

class HeaderView: UITableViewHeaderFooterView {
    
}


extension UIView {
    func noCorners() {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: [.allCorners], cornerRadii: CGSize(width: 0, height: 0))
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        layer.mask = shape
    }
    
    func applyCorners(to: UIRectCorner, with rect: CGRect) {
        let path = UIBezierPath(roundedRect: rect, byRoundingCorners: to, cornerRadii: CGSize(width: 10, height: 10))
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        layer.mask = shape
    }
}