后退按钮文字颜色恢复为默认值

Question

I am having an issue in my app with a particular back button changing font colour for no apparent reason. I have been through all of my code and I can't see any reason for it, but when launching my app and segueing to the problem view controller, the text colour seems to be set to the default blue colour.

If I tap to go to a different tab and then go back to this view controller, then the font returns to the correct colour (white) and this is despite not having any code in viewWillAppear/Disappear viewDidAppear/Disappear.

The code I am using to set the navigation bar text colour is:

override func awakeFromNib() {
    var attributes = [NSForegroundColorAttributeName: UIColor.whiteColor(),NSFontAttributeName: UIFont(name: "Avenir", size: 24)!]
    self.navigationController?.navigationBar.titleTextAttributes = attributes
}

And this is in the view controller that is segued from when going to the view controller with the back button. I have tried adding this code into viewWillAppear() but even this doesn't make a difference.

Does anyone know why, on launch, my app doesn't set the back button text colour and requires a tab switch for it to update?

Answer 1

请尝试在视图将出现的方法中编写相同的代码。

Answer 2

I think this code will work

self.navigationController?.navigationBar.barTintColor = UIColor.someColor() 
//This sets the background colour of the navigation bar

self.navigationController?.navigationBar.tintColor = UIColor.someColor()
// This sets the colour for navigation and bar button items 

self.navigationController?.navigationBar.titleTextAttributes = [ NSFontAttributeName: UIFont(name: "someFont", size: 20)!,  NSForegroundColorAttributeName: UIColor.blackColor()]
//This sets the attributed text for the title of the navigation bar

UIBarButtonItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.blackColor(), NSFontAttributeName: UIFont(name: "someFont", size: 17)!], forState: .Normal)
//And this sets the attributed text for the bar button item(s) on the navigation bar (So that includes the back button)

Call it in the viewWillAppear I hope this works :)