我是 Swift 编程的新手,并且可能正在使用一些构造,该构造在设置一次后使值不可变。我有一个运行 JavaScript webapp 的 WKWebView,并且在那个 JS 中,一个 URL 被这样调用:
var url = 'testscheme://x-callback/test?unique=' + new Date().getTime() + 'Z';
window.location = url;
Ext.toast(url, 30000);
这反过来会在我的 Swift 代码中触发下面的扩展。麻烦的是,第一次调用扩展时,它有来自 JS 的正确 URL;但在那之后,第一个 URL 似乎以某种方式“卡住”了,并且无论何时再次调用它,它都会继续打印第一个 URL 值,而不是来自任何后续调用的值,这些调用中包含不同的信息。
extension VCWebView: WKURLSchemeHandler {
// any requests for a URL scheme should arrive here
func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
print("In WKURLSchemeHandler webView()")
print("url absolute string requested: " + (urlSchemeTask.request.url?.absoluteString ?? "{nil}"))
// THE LINE above is where it should be printing a unique value every time it is run,
// but gets stuck with the value from the first time it was run
}
// not used
func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {
}
}
我知道 JS 正在发送唯一信息,因为当我关闭应用程序并重新启动它时,它第一次再次具有唯一值,但此后任何时候再次运行时都会继续显示第一个唯一值。有一些我不理解的日志文件条目(第二次尝试后 09:42:01 的 4):
testscheme url scheme registered
in VCWebView.swift viewDidLoad()
{1ST ATTEMPT}
09:41:12.904692-0700 MyApp[51948:6316047] [ProcessSwapping] 0x10a1842c0 - ProvisionalPageProxy::ProvisionalPageProxy: pageID = 6 navigationID = 4 suspendedPage: 0x0
In WKURLSchemeHandler webView()
url absolute string requested: testscheme://x-callback/test?unique=1570293672897Z {THIS IS WHAT JS SENT: ...897Z so this one is correct}
{2ND ATTEMPT}
09:42:01.516773-0700 MyApp[51948:6316047] [ProcessSwapping] 0x10a1842c0 - ProvisionalPageProxy::didFailProvisionalLoadForFrame: pageID = 6, frameID = 1, navigationID = 4
09:42:01.520345-0700 MyApp[51948:6316047] [ProcessSwapping] 0x10a184420 - ProvisionalPageProxy::ProvisionalPageProxy: pageID = 6 navigationID = 5 suspendedPage: 0x0
09:42:01.632990-0700 MyApp[51948:6316047] [ProcessSuspension] 0x10a1f72d0 - ProcessAssertion::processAssertionWasInvalidated()
09:42:01.633186-0700 MyApp[51948:6316047] [ProcessSuspension] 0x10a1f7f00 - ProcessAssertion::processAssertionWasInvalidated()
In WKURLSchemeHandler webView()
url absolute string requested: testscheme://x-callback/test?unique=1570293672897Z {THIS IS WHAT JS SENT: ...512Z}
09:42:31.520976-0700 MyApp[51948:6316047] [assertion] Error acquiring assertion: <NSError: 0x600002efdcb0; domain: RBSAssertionErrorDomain; code: 2; reason: "Specified target process does not exist">
09:42:31.521453-0700 MyApp[51948:6316047] Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service
这些日志文件条目可能解释了它失败的原因,但我不知道如何修复它。任何想法我做错了什么?