ios - 快速设置整个应用程序的导航栏后退按钮图像

Question

我正在 AddDelegate 中设置导航栏后退按钮，但设置不正确。

我试过下面的代码:

let backButtonImage = backImage?.withRenderingMode(.alwaysOriginal).resizableImage(withCapInsets: UIEdgeInsetsMake((backImage?.size.height)!, (backImage?.size.width)!, 0, 0))
UIBarButtonItem.appearance().setBackButtonBackgroundImage(backButtonImage, for: .normal, barMetrics: .default)
UIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(-400, 0), for: .default)

来自 here .

但用户界面不正确:

我也试过下面的代码:

UINavigationBar.appearance().backIndicatorImage = backButtonImage
UINavigationBar.appearance().backIndicatorTransitionMaskImage = backButtonImage
UIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(0, -80.0), for: .default)

看起来像这样:

但它在终端中给出了约束问题:

[LayoutConstraints] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<NSLayoutConstraint:0x600000098510 UILayoutGuide:0x6040007aca20'BackButtonGuide(0x7f8143611390)'.height == 44   (active)>",
    "<NSLayoutConstraint:0x60000029e320 _UIButtonBarButton:0x7f814349d110.top == UILayoutGuide:0x6040007aca20'BackButtonGuide(0x7f8143611390)'.top   (active)>",
    "<NSLayoutConstraint:0x60000029de20 _UIButtonBarButton:0x7f814349d110.bottom == UILayoutGuide:0x6040007aca20'BackButtonGuide(0x7f8143611390)'.bottom   (active)>",
    "<NSLayoutConstraint:0x60400049d790 _UIModernBarButton:0x7f81434a4800'Back'.lastBaseline == UILayoutGuide:0x6000001b51c0'UIViewLayoutMarginsGuide'.bottom - 80   (active)>",
    "<NSLayoutConstraint:0x60400049d1a0 _UIModernBarButton:0x7f81434a4800'Back'.top >= _UIButtonBarButton:0x7f814349d110.top   (active)>",
    "<NSLayoutConstraint:0x600000481040 UIButtonLabel:0x7f81434a30d0'Back'.centerY == _UIModernBarButton:0x7f81434a4800'Back'.centerY + 1.5   (active)>",
    "<NSLayoutConstraint:0x60000029ea00 'UIView-bottomMargin-guide-constraint' V:[UILayoutGuide:0x6000001b51c0'UIViewLayoutMarginsGuide']-(16)-|   (active, names: '|':_UIButtonBarButton:0x7f814349d110 )>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000481040 UIButtonLabel:0x7f81434a30d0'Back'.centerY == _UIModernBarButton:0x7f81434a4800'Back'.centerY + 1.5   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.


[LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want.
    Try this:
    (1) look at each constraint and try to figure out which you don't expect; 

(2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<NSLayoutConstraint:0x60000029f1d0 _UIModernBarButton:0x7f814360f630.bottom == UILayoutGuide:0x6040007ac940'UIViewLayoutMarginsGuide'.bottom + 84.5   (active)>",
    "<NSLayoutConstraint:0x600000287bc0 V:[_UIModernBarButton:0x7f814360f630]-(>=0)-|   (active, names: '|':_UIButtonBarButton:0x7f814360d8a0 )>",
    "<NSLayoutConstraint:0x604000488930 'UIView-bottomMargin-guide-constraint' V:[UILayoutGuide:0x6040007ac940'UIViewLayoutMarginsGuide']-(16)-|   (active, names: '|':_UIButtonBarButton:0x7f814360d8a0 )>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x60000029f1d0 _UIModernBarButton:0x7f814360f630.bottom == UILayoutGuide:0x6040007ac940'UIViewLayoutMarginsGuide'.bottom + 84.5   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

还有其他方法吗，还是我做错了什么？

Answer 1

引用@Rajamohan-s 的回答:

Change UINavigationBar back button text and font from AppDelegate using Swift

你可以用下面的代码来做;

 extension UINavigationItem{

    override open func awakeFromNib() {
        super.awakeFromNib()

        let backItem = UIBarButtonItem()
        backItem.title = "Hello"


        if let font = UIFont(name: "Copperplate-Light", size: 32){
            backItem.setTitleTextAttributes([NSFontAttributeName:font], for: .normal)
        }else{

            print("Font Not available")
        }
        /*Changing color*/
        backItem.setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.green], for: .normal)

        self.backBarButtonItem = backItem
    }

}