从另一个 .swift 文件调用 ViewController 函数

Posted 2023-02-23

【中文标题】从另一个 .swift 文件调用 ViewController 函数

【英文标题】：Calling ViewController function from another .swift file

【发布时间】：2020-08-02 10:11:22

【问题描述】：

我有一个collectionView，一旦收到某些数据，我想reloadData()。问题是：我不知道如何从另一个处理数据的 .swift 文件中调用 ViewController 函数。我试着做：

class WebSocketLogic: WebSocketDelegate 
    var viewController = ViewController()
    var columns = 0
    var rows = 0
...
    func receiveData 
        ...
        columns = map.count
        rows = map[0].count
        viewController.collectionView.reloadData()
    

它在ViewController() 初始化行上给了我Thread 1: EXC_BAD_ACCESS (code=2, address=0x7ffeec870fe8) 错误。 我也尝试过：

class ViewController: UIViewController 
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    var webSocket = WebSocketLogic(roomId: 1)
    var columns = 0 
        didSet 
            collectionView.reloadData()
            print("columns number set to: \(columns)")
        
    
    var rows = 0  

    override func viewDidLoad() 
        super.viewDidLoad()
        
        webSocket.setupStarScream()
        columns = webSocket.columns
        rows = webSocket.rows
    

但由于某种原因，didSet 只在开始时被调用一次。 一旦receiveData()func 在另一个文件中完成，我该怎么做才能在ViewController 中调用reloadData()？

【参考方案1】：

您可以使用delegation pattern

protocol DataDelegate 
    func dataReceived()


class WebSocketLogic: WebSocketDelegate 
    var delegate: DataDelegate?
    var columns = 0
    var rows = 0
...
    func receiveData 
        ...
        columns = map.count
        rows = map[0].count
        delegate?.dataReceived()
    


class ViewController: UIViewController, DataDelegate 
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    var webSocket = WebSocketLogic(roomId: 1)
    var columns = 0 
        didSet 
            collectionView.reloadData()
            print("columns number set to: \(columns)")
        
    
    var rows = 0  

    override func viewDidLoad() 
        super.viewDidLoad()
        webSocket.delegate = self
        
        webSocket.setupStarScream()
        columns = webSocket.columns
        rows = webSocket.rows
    
   
    func dataReceived() 
        collectionView.reloadData()