你需要在你的单元格中实现 UIWebViewDelegate 并将你的单元格设置为 delegate 然后在方法 webViewDidStartLoad 你会收到通知

You need to implement UIWebViewDelegate in your cell and set you cell as delegate then in the method webViewDidStartLoad you will be notified

import UIKit
import WebKit

class SearchCollectionViewCell: UICollectionViewCell {


    @IBOutlet weak var webView: UIWebView!

    @IBOutlet weak var spinner: UIActivityIndicatorView!

    override func awakeFromNib() {
        super.awakeFromNib()
        self.webView.delegate = self
        // Initialization code
    }

}

extension SearchCollectionViewCell : UIWebViewDelegate
{
    public func webViewDidStartLoad(_ webView: UIWebView) {
        debugPrint("Start Loading")
    }
}

希望能帮到你