Changing the text color of a navigation bar title

问题:

I have a requirement in which I have to use a UINavigationBar with a red large title.

Currently, I have the following code:

func prepareNavigationController() {
    let navController = UINavigationController(rootViewController: self)
    navController.navigationBar.prefersLargeTitles = true
    navigationItem.searchController = UISearchController(searchResultsController: nil)
    navigationItem.hidesSearchBarWhenScrolling = false
    navController.navigationBar.titleTextAttributes = [NSAttributedStringKey.foregroundColor.rawValue: UIColor.red]
}

But it's not actually tinting the title label to red. This is the result:

But changing prefersLargeTitles to false does the right thing, and my title is red.

navController.navigationBar.prefersLargeTitles = false

I am not entirely sure if this is a bug since at the time of this writing we are still in the first beta, or if this is intentional behavior, mostly because I haven't any of Apple's apps color the large titles before. Is there any way to actually get the large title to have any color I want?

回答1:

There is a new UINavigationBar property "largeTitleTextAttribute" that should help with this.

largeTitleTextAttribute

Here is a sample code you can add to your view controllers viewDidLoad method

        navigationController?.navigationBar.largeTitleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.blue]

Here is a sample code and screenshot without the largeTitleTextAttributes set, but the barStyle is set to .black

        navigationController?.navigationBar.barStyle = .black

Here is a screenshot without the largeTitleTextAttributes set, but the barStyle is set to .default

        navigationController?.navigationBar.barStyle = .default

回答2:

Not sure if it's a bug in beta 1 & 2, but here is a way to set the color. It's a bit of a "hacky" workaround, but it should work until Apple fixes this. In both the Objective-C and Swift version, this code goes in the viewDidAppear: method.

Objective-C:

dispatch_async(dispatch_get_main_queue(), ^{
    for (UIView *view in self.navigationController.navigationBar.subviews) {
        NSArray <__kindof UIView *> *subviews = view.subviews;
        if (subviews.count > 0) {
            UILabel *label = subviews[0];
            if (label.class == [UILabel class]) {
                [label setTextColor:[UIColor redColor]];
            }
        }
    }
});

Swift:

DispatchQueue.main.async {
     for view in self.navigationController?.navigationBar.subviews ?? [] {  
     let subviews = view.subviews  
     if subviews.count > 0, let label = subviews[0] as? UILabel {  
           label.textColor = UIColor.red
 } } }

回答3:

Here's the working code to use large titles and sets the text color of small and large titles to white, both on iOS11+ and on older iOS versions.

// Will apply to versions before iOS 11
navigationController?.navigationBar.titleTextAttributes = [
    NSAttributedStringKey.foregroundColor: UIColor.white
]

if #available(iOS 11.0, *) {
    navigationController?.navigationBar.prefersLargeTitles = true
    navigationController?.navigationBar.largeTitleTextAttributes = [
        NSAttributedStringKey.foregroundColor: UIColor.white
    ]
}

(There used to be a bug in Xcode, but it now appears to be fixed)

回答4:

If using storyboard, just change "Large Title Text Attributes" Title Color at Navigation Bar Attribute Inspector: