在 iphone 上创建仅包含自定义 viewcontroller class 的弹出概览

Creating a popoverview with only custom viewcontroller class on iphone

我正在尝试在 iPhone 上实现一个 popovercontroller,它具有类似于 iPad 的模态表示。我只能在使用故事板时生成 UI,我更愿意完全以编程方式构建控制器。 SO 和 google 上的所有演示似乎都使用故事板。我可以从我的自定义 UIViewController 打印到日志中看到方法,但模态弹出窗口中没有任何内容。 Showing Popover view

    func handlePop(sender: UIButton) {

      //let popController:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "unique") as UIViewController //only way I generate UI in popoverview

      let popController = MyCustomViewController()  //would like to use

     //positioning 
    let placementView = UIView()
    view.addSubview(placementView)
    view.addConstraintsWithFormat("H:|[v0]|", views: placementView)
    view.addConstraintsWithFormat("H:|-64-[v0(200)]", views: placementView)

    popController.modalPresentationStyle = UIModalPresentationStyle.popover
    if let poppingVC = popController.popoverPresentationController {


        let popover: UIPopoverPresentationController = poppingVC

        popover.sourceView = placementView
        popover.permittedArrowDirections = .up
        popover.sourceRect = CGRect(x: view.frame.width / 2, y: -100, width: 0, height: 100)

        popover.delegate = self

        self.present(popController, animated: true, completion:nil)
    }

}

func dismissView() {
    self.dismiss(animated: true, completion: nil)
}
func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
    return UIModalPresentationStyle.none
}

我错过了什么让 popovercontroller 保持空白?

    class RegionSelectionController: UIViewController, UIPopoverPresentationControllerDelegate, UITableViewDelegate, UITableViewDataSource {



let mainLabel = UILabel()
let cellId = "cellId"
let footerId = "footerId"
var keys = [String]()

let tableView = UITableView()


override func viewDidLoad() {
    super.viewDidLoad()


    tableView.delegate = self
    tableView.dataSource = self



    self.view.addSubview(tableView)

    tableView.register(RegionFilterCell.self, forCellReuseIdentifier: cellId)
    tableView.separatorStyle = .none

    tableView.delegate = self

}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    print(keys.count)
    return keys.count

}
func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! RegionFilterCell

    let regionName = keys[indexPath.row]
    cell.regionLabel.text = regionName

    return cell

}

 func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
    let footerCell = RegionRequestNewLocationCell()


    return footerCell
}
 func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
    return 100
}

 func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    print(indexPath.row, keys[indexPath.row])
}




override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    ref.child("Region").observeSingleEvent(of: .childAdded, with: { (snap) in
        if snap.exists() {

            let key: String = snap.key as String
            self.keys.append(key)
        }
        DispatchQueue.main.async ( execute: {
            self.tableView.reloadData()
        })
    })


}

}

  class RegionFilterCell: BaseTableCell {

let regionLabel: UILabel = {
    let label = UILabel()
    label.font = UIFont(name: "SFUIText-Medium", size: 16)
    label.text = "UMD"
    return label
}()

let separatorBar: UIView = {
    let view = UIView()
    view.backgroundColor = UIColor.rgb(151, green: 151, blue: 151, alpha: 0.3)
    return view
}()
override func setupViews() {
    super.setupViews()

    addSubview(regionLabel)
    addSubview(separatorBar)
    //addConstraintsWithFormat("H:[v0(100)]", views: regionLabel)
    addConstraint(NSLayoutConstraint(item: regionLabel, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0))
    addConstraintsWithFormat("V:|[v0]|", views: regionLabel)
    addConstraintsWithFormat("H:|[v0]|", views: separatorBar)
    addConstraintsWithFormat("V:[v0(0.5)]|", views: separatorBar)
}

}

从您所展示的内容来看,您永远不会在正在展示的 ViewController 中为您的内容设置框架(在本例中是您的 UITableView)。如果你不为视图设置框架,它就不会显示在屏幕上。您需要使用 CGRect 指定原点和大小,或者使用 NSLayoutConstraints 的自动布局。最简单的方法就是一个框架。所以在 viewDidLoad 中,假设你想让 tableView 占据整个视图:

tableView.frame = CGRect(x: 0, y: 0, width: view.bounds.width, height: view.bounds.height)

您还需要确保实例化正确 VC。我不知道您是否只是出于示例的目的使用名称 MyCustomViewController,但是您在代码中显示的 VC 被命名为 RegionSelectionController