更改UIBarButtonItem的色调颜色

// 设置所有 UIBarButtonItem 的 tint color
UIBarButtonItem.appearance().tintColor = UIColor.blue

// 设置特定 UIBarButtonItem 的 tint color
let button = UIBarButtonItem(title: "Button", style: .plain, target: self, action: #selector(buttonTapped))
button.tintColor = UIColor.red

let button = UIBarButtonItem(title: "Button", style: .plain, target: self, action: #selector(buttonTapped))
button.tintColor = UIColor.green

override func viewDidLoad() {
    super.viewDidLoad()
    // 确保在 viewDidLoad 之后调用
    UIBarButtonItem.appearance().tintColor = UIColor.blue
}

let button = UIBarButtonItem(title: "Button", style: .plain, target: self, action: #selector(buttonTapped))
button.tintColor = UIColor.blue.withAlphaComponent(0.8)