wkwebview显示白色屏幕（目标C）

Question

我已将wkwebview集成到我的应用程序中 wkwebview需要很长时间才能加载。 第一次显示白屏，并在10-15秒后加载。 我怀疑这与加载有关吗？我只是不确定如何准确地确定我在做什么错。

WKPreferences * preferences = [[WKPreferences alloc] init];                 preferences.javaScriptEnabled = YES;

            // Disable zoom in/out in WKWebView
            NSString *source = @"var meta = document.createElement('meta'); meta.name = 'viewport'; meta.content = 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no'; var head = document.getElementsByTagName('head')[0]; head.appendChild(meta);";
            WKUserScript *script = [[WKUserScript alloc] initWithSource:source injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
            WKUserContentController *userContentController = [[WKUserContentController alloc] init];
            WKWebViewConfiguration *theConfiguration = [[WKWebViewConfiguration alloc] init];
            theConfiguration.userContentController = userContentController;
            [userContentController addUserScript:script];

            WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectZero  configuration:theConfiguration];
            theConfiguration.preferences = preferences;

            webView.scrollView.alwaysBounceHorizontal = NO;
            webView.scrollView.showsVerticalScrollIndicator = NO;
            webView.scrollView.showsHorizontalScrollIndicator = NO;
            webView.scrollView.bounces = NO;
            webView.scrollView.delegate = self;
            webView.navigationDelegate = self;
            webView.UIDelegate = self;
            webView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth   ;
                        [webView loadRequest:request];