我正在尝试使用WkWebKit在应用和页面之间来回交谈。我可以使用WkWebView evaluateJavascript方法让javaScript执行得很好，但是当我尝试在JavaScript页面上执行window.webkit.messageHandlers.myHandler.postMessage（'hello world！'）时，我发现window.webkit没有定义。 / p>
奇怪......我正在ios 8.4的iPad模拟器中运行。我认为这可以在原始版本8中找到，不是吗？
我找不到其他任何关于此的帖子，所以也许我做错了什么？
我甚至将我的Safari Developer连接到模拟器的浏览器，在控制台中我试着看看window.webkit是什么，当然，它不存在。
请注意，我添加了一个在页面加载时运行的初始脚本（我在javascript编辑器中看到了这一点 - 记录了消息）。我还添加了一个脚本消息处理程序...
[编辑：在此处添加更多代码详情] 这是我的代码：
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSLog(@"main view Controller viewDidLoad called...");
// if we are running on an OLD ios (pre v8) WKWebView will not exist. So don't create it if it doesn't exist...
if (NSClassFromString(@"WKWebView")) {
// WKWebView cannot be dragged onto storyboard, so have to create it manually here.
// We have a "ContainerView" called _webContainer that this browser view will live inside
// First we create a web view configuration object...
WKWebViewConfiguration *wbConfig = [WKWebViewConfiguration alloc];
wbConfig.mediaPlaybackAllowsAirPlay = true;
wbConfig.mediaPlaybackRequiresUserAction = false;
// inject some Javascript into our page before it even loads...
NSString *scriptSource = @"console.log('Hi from the iOS app hosting this page...'); window.hostedByWkWebView=true;";
WKUserScript *userScript = [[WKUserScript alloc]
initWithSource:scriptSource
injectionTime:WKUserScriptInjectionTimeAtDocumentStart
forMainFrameOnly:YES];
[wbConfig.userContentController addUserScript:userScript];
[wbConfig.userContentController addScriptMessageHandler:self name:@"myHandler"]; // javascript to use this would be: window.webkit.messageHandlers.myHandler.postMessage
// Ok, the config is created, now create the WkWebView instance, passing in this config...
_webView = [[WKWebView alloc] initWithFrame: [_webContainer bounds] configuration:wbConfig];
_webView.autoresizesSubviews = true;
_webView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
_webView.navigationDelegate = self;
// Add the web view to the container view, and tell the container to automatically resize its subviews, height and width.
[_webContainer addSubview:_webView];
_webContainer.autoresizesSubviews = true;
_webContainer.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
// Set the URL for the webview and navigate there...
NSString *fullURL = @"https://myurlgoeshere.com";
NSURL *url = [NSURL URLWithString:fullURL];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[_webView loadRequest:requestObj];
}
else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Cannot create Web View" message:@"The web view used requires iOS 8 or higher. Sorry." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:@"", nil];
[alert show];
}
//...
答案 0 :(得分：20)
我解决了问题，问题是，如果您将userContentController设置为新对象，则userContentController WKScriptMessageHandler将无法在Apple＆＃39;中正确注册内部代码：
WKUserContentController *userContentController = [WKUserContentController new];
userContentController.addScriptMessageHandler(self, name: "jockey")
userContentController.addScriptMessageHandler(self, name: "observe")
webView.configuration.userContentController = userContentController
使用Apple已经实例化的userContentController修复：
webView.configuration.userContentController.addScriptMessageHandler(self, name: "jockey")
webView.configuration.userContentController.addScriptMessageHandler(self, name: "observe")
答案 1 :(得分：4)
window.webkit命名空间仅出现在带有脚本消息处理程序的webview中。 确保已调用WKUserContentController的addScriptMessageHandler方法。
答案 2 :(得分：3)
我遇到了这个SO，因为我遇到了同样的问题，这就是我使用自定义CustomContentController（WKUserContentController）实例的子类解决它的方法。
let userContentController = CustomContentController()
let webViewConfiguration = WKWebViewConfiguration()
webViewConfiguration.userContentController = userContentController
webView = WKWebView(frame: .zero, configuration: webViewConfiguration)
在我的情况下，CustomContentController是WKUserContentController的子类，其中add(_ scriptMessageHandler: WKScriptMessageHandler, name: String)方法被调用，但我不认为这是重要的。
我认为必须先实例化WKUserContentController并将其应用于WKWebViewConfiguration ，然后才能通过WKWebView(frame: .zero, configuration: webViewConfiguration)
如果已创建WKWebView并然后，则尝试更改WKWebViewConfiguration，您将遇到JSContext中无法使用的window.webkit。
答案 3 :(得分：0)
我遇到了同样的问题。浪费了2个小时之后，我发现下面这个工作正常。但我不知道为什么。
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
WKUserContentController *userCctrl = [[WKUserContentController alloc] init];
[userCctrl addScriptMessageHandler:self name:@"jscall"];
WKWebViewConfiguration *wbConfiger = [[WKWebViewConfiguration alloc] init];
wbConfiger.userContentController = userCctrl;
CGSize size = [UIScreen mainScreen].bounds.size;
WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20, size.width, size.height - 20) configuration:wbConfiger];
[self.view addSubview:webView];
webView.UIDelegate = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[webView evaluateJavaScript:@"if (window.webkit === undefined) { alert('未注册的 window.webkit'); } else { window.webkit.messageHandlers.jscall.postMessage({title:'标题'}); }" completionHandler:^(id obj, NSError *error) {
NSLog(@"run js completion with error = %@", error);
}];
});
}
#pragma mark -
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
NSLog(@"run js alert panel message = %@", message);
completionHandler();
}
#pragma mark -
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
NSLog(@"wkwebview run javascript name = %@, body = %@", message.name, message.body);
}
答案 4 :(得分：0)
最后为我提供的解决方案是使用
在 webview 上启用 javascriptwebview?.configuration.preferences.javaScriptEnabled = true