UIwebView 解决返回自动刷新问题

    [[NSUserDefaults
standardUserDefaults]
setInteger:2
forKey: @"WebKitCacheModelPreferenceKey"];

    [[NSUserDefaults
standardUserDefaults]
setInteger:1
forKey: @"WebKitMediaPlaybackAllowsInline"];

    id webView = [self.webView
valueForKeyPath:@"_internal.browserView._webView"];

    id preferences = [webView
valueForKey:@"preferences"];

    [preferences performSelector:@selector(_postCacheModelChangedNotification)];