webView返回不刷新

    [[NSUserDefaults standardUserDefaults] setInteger:2 forKey: @"WebKitCacheModelPreferenceKey"];
    [[NSUserDefaults standardUserDefaults] setInteger:1 forKey: @"WebKitMediaPlaybackAllowsInline"];
    id webView = [self.wbBanner valueForKeyPath:@"_internal.browserView._webView"];
    id preferences = [webView valueForKey:@"preferences"];
    [preferences performSelector:@selector(_postCacheModelChangedNotification)];

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