ios - UIActivityIndi​​catorView 未显示在 web View 中

Question

我有一个要添加 UIViewController 的 UINavigationController。在我的 UIViewController 中，我有一个 webview，并且还试图设置一个 UIActivityIndi​​catorView。但是我似乎无法让 UIActivityIndi​​catorView 显示出来。任何帮助都会很棒!

class TestWebViewController: UIViewController {

    var loadSpinner: UIActivityIndicatorView!

    var webView: UIWebView!

    var title: String?

    init(title: String?) {
       self.title = title

       self.webView = UIWebView(frame: CGRect.zero)
       super.init(nibName: nil, bundle: nil)
       commonInit()
    }

    func commonInit() {
       loadSpinner = UIActivityIndicatorView(activityIndicatorStyle: .gray)
       loadSpinner.center = webView.center
       view.addSubview(loadSpinner)
       webView.delegate = self
       view = webView
    }

    required init?(coder aDecoder: NSCoder) {
       fatalError("init(coder:) has not been implemented")
    }

UINavigationController(rootViewController: testWebViewController)

即使我尝试将 loadSpinner 添加到 webView，它也不会出现 webView.addSubview(loadSpinner)

Answer 1

结果:

代码:

class ViewController: UIViewController {

var loadSpinner: UIActivityIndicatorView!
var webView: UIWebView!

override func viewDidLoad() {
    super.viewDidLoad()

    self.webView = UIWebView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

    loadSpinner = UIActivityIndicatorView(activityIndicatorStyle: .gray)

    webView.addSubview(loadSpinner)

    view = webView

    loadSpinner.startAnimating()
}

override func viewDidLayoutSubviews() {
    loadSpinner.center = webView.center
}
}