iOS 重构解耦： UIViewController 以 pop

UIViewController 视图化 popover 箭头形式呈现。

class FourthViewController: UIViewController {

    @objc func showPopoverAction(_ sender: UIButton) {

        let popoverContentVC = PopoverViewController()
        popoverContentVC.preferredContentSize = CGSize(width: kScreenWidth - 20, height: 400)
        popoverContentVC.modalPresentationStyle = .popover
        guard let popoverPresentationVC = popoverContentVC.popoverPresentationController else { return }
        popoverPresentationVC.permittedArrowDirections = .up
        popoverPresentationVC.sourceView = self.view
        popoverPresentationVC.sourceRect = sender.frame
        popoverPresentationVC.delegate = self
        present(popoverContentVC, animated: true, completion: nil)        
    }
}

extension FourthViewController: UIPopoverPresentationControllerDelegate {

    func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
        return .none
    }
     
    func popoverPresentationControllerShouldDismissPopover(_ popoverPresentationController: UIPopoverPresentationController) -> Bool {
        return true
    }
    
    func popoverPresentationControllerDidDismissPopover(_ popoverPresentationController: UIPopoverPresentationController) {
    }

    func prepareForPopoverPresentation(_ popoverPresentationController: UIPopoverPresentationController) {
    }
}

import UIKit
import SwiftExpand
import SnapKit

class PopoverViewController: UIViewController {

    lazy var button: UIButton = {
        let sender = UIButton(type: .custom)
        sender.setTitle("UIButton", for: .normal)
        sender.setTitleColor(UIColor.yellow, for: .normal)
        sender.addActionHandler({ (control) in
            guard let sender = control as? UIButton else { return }
            DDLog(sender.currentTitle)
            
        }, for: .touchUpInside)
        
        return sender
    }()
    
    // MARK: -lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor.lightGreen
        
        view.addSubview(button)
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        button.snp.makeConstraints { (make) in
            make.centerX.equalToSuperview().offset(0)
            make.top.equalToSuperview().offset(130);
            make.width.equalTo(100);
            make.height.equalTo(25);
        }
    }
}

github