每次启动时 UIWebView 白屏，同时预加载所有选项卡 [英] UIWebView white screen on every launch while preloading all tabs

问题描述

在我提出我的问题之前，我想提一下我尝试寻找解决方案此处 和 此处.
我正在创建一个混合应用程序，它使用本机 UIWebView 来呈现响应式设计的 Web 应用程序.以下是问题描述:
1. 我有一个 UITabBarController.
2. 每个标签都有一个UIWebView.
3. 我必须预加载所有标签.
4. 我正在显示 UIActivityIndi​​cator 直到内容加载到第一个选项卡上.
5. 白屏出现约8-10秒，然后开始出现内容.
我会很高兴看到这个时间变成2-4 秒.

Before I present my issue, I want to mention that I tried looking for solutions here and here.
I am creating a hybrid application which uses native UIWebView for rendering the responsive designed web application. Following is the issue description :
1. I have a UITabBarController.
2. Each of the tab has a UIWebView.
3. I have to preload all tabs.
4. I am showing a UIActivityIndicator till the content loads on the first tab.
5. White screen appears for about 8-10 seconds and then the content starts to appear.
I will be happy to see this time become 2-4 seconds.

以下是我的实现:

[self performSelectorOnMainThread:@selector(loadAllTabs) withObject:nil waitUntilDone:YES];

-(void) loadAllTabs
{
    for(UIViewController * viewController in  self.viewControllers){
        if(![[NSUserDefaults standardUserDefaults]boolForKey:@"isSessionExpired"])
        {
            if((int)[self.viewControllers indexOfObject:viewController] != 4)
            {
                viewController.tabBarItem.tag = (int)[[self viewControllers] indexOfObject:viewController];
                [viewController view];
            }
        }
    }
}

在 WebView 控制器的 viewDidLoad 中，我有:

In WebView controller's viewDidLoad I have :

[_tgWebView loadRequest:[NSURLRequest requestWithURL:homeURL]];  

我很期待suppressesIncrementalRendering，但由于我正在预加载所有选项卡，因此这不起作用.由于我的应用支持 iOS 7+，因此 WKWebView 不能在这里应用.
我还想到了增加启动图像的持续时间，但了解到这不是一个好习惯.
这可以使用 GCD 实现吗?
请指出我的实现中的缺陷，以便我的应用程序获得更好的性能.

I was looking forward to suppressesIncrementalRendering, but since I am preloading all tabs, this does not work. Since my app supports iOS 7+, thus WKWebView can't be applied here.
I also thought of increasing the launch image duration but learned that is won't be a good practice.
Can this be implemented using GCD?
Please bring out the pitfalls in my implementations so that my application makes better performance.

推荐答案

这篇 帖子让我开心.我现在为此使用 NSNotificationCenter.

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