CNContactViewController navigation bar different between versions

Question

Our tint color is white. Our app uses CNContactViewController. In our version of the app in the store built with Xcode 7 targeting iOS 8 and 9, if you were iOS 9 we called

Answer 1

By using Debug View Hierarchy of XCode, I find the alpha of the subview named "_UIBarBackground" of UINavigationBar turns to be 0 after CNContactViewController has been pushed.

The following code helps me solve the problem (It works well in iOS 11):

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        for (UIView *view in self.navigationController.navigationBar.subviews) {
            if ([view isKindOfClass:NSClassFromString(@"_UIBarBackground")]) {
                view.alpha = 1;
                break;
            }
        }
    });