代表:传递数据而不会引起争执 [英] Delegates: pass data without segue

问题描述

我有两个简单的类，可以像这样通过委托传递信息:

I have two simple classes that pass information with delegates like so:

protocol VCBDelegate: class {
func buttonDidPress() }

class ViewControllerBefore: UIViewController {

weak var delegate: VCBDelegate?
let vc = ViewController()

override func viewDidLoad() {
    super.viewDidLoad()
    self.delegate = vc
}

@IBAction func press(_ sender: Any) {
    delegate?.buttonDidPress()
} }

class ViewController: UIViewController, VCBDelegate {

override func viewDidLoad() {
    super.viewDidLoad()
}

一切正常，并触发了buttonDidPress功能.但是我的问题是，如果我想重新加载集合视图，则由于我在ViewControllerBefore类中实例化ViewController对象的方式，该集合视图为nil.请记住，由于两个视图控制器未连接，因此我无法在segue中分配委托.

Everything works fine and the function buttonDidPress is triggered. But my problem is that if I want to reload a collection view, then the collection view is nil because of the way I instantiate the ViewController object in the ViewControllerBefore class. Keep in mind that I cannot assign the delegate in a segue, because the two view controllers are not connected.

请参见buttonDidPress函数下方的内容:

See here below the buttonDidPress function:

func buttonDidPress() {         
  dataCell.infoCell.insert(addDataCell.getBuyCell(), at: 0)
  self.cvHome.reloadData()
}

推荐答案

在这种情况下，我喜欢将数据存储在 dataSource 内部.设置完毕后，我可以从应用程序中的任何位置访问数据.

I like to store the data inside of a dataSource for these circumstances. I can access the data from anywhere in the app once it's been set.

class PageDataSource {

    var theData : [Any]?

    static let sharedInstance = PageDataSource()
    private init() {}
}

为确保我将信息通过 delegate 传递并将其存储到 dataSource 中，我执行以下操作:

To make sure I pass the info through the delegate and I store it to the dataSource I do this:

func doDelegate() {
    PageDataSource.sharedInstance.theData = whatever
    passData(whatever)
    dismiss(true, nil)
}

然后，我确保 tableView 或 collectionView 正在从 PageDataSource.sharedInstance.theData 获取所需的信息，例如:

Then I make sure that the tableView or collectionView is getting the information it needs from PageDataSource.sharedInstance.theData for example:

// MARK: CollectionView DataSource
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if PageDataSource.sharedInstance.theData.count >= 1 {
            return PageDataSource.sharedInstance.theData.count
        }
        return 0
    }

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