UIKit导航栏：修改返回按钮图标及增加边距的技术问题

1. 彻底移除返回按钮文字（保留原生手势） #

你的现有方案可行，这里提供更彻底的实现方式，直接将文字偏移至不可见区域，避免透明文字可能残留的布局占位问题：

extension UINavigationBar {
    func applyAppearance(backgroundColor: UIColor, textColor: UIColor) {
        let appearance = UINavigationBarAppearance()
        appearance.configureWithOpaqueBackground()
        appearance.backgroundColor = backgroundColor
        appearance.shadowColor = .clear
        appearance.titleTextAttributes = [.foregroundColor: textColor]
        
        // 移除返回按钮文字：将文字偏移到屏幕外
        let backButtonAppearance = UIBarButtonItemAppearance(style: .plain)
        backButtonAppearance.normal.titlePositionAdjustment = UIOffset(horizontal: -1000, vertical: 0)
        appearance.backButtonAppearance = backButtonAppearance
        
        tintColor = textColor
        standardAppearance = appearance
        scrollEdgeAppearance = appearance
        compactScrollEdgeAppearance = appearance
    }
}

2. 调整返回箭头左侧边距 #

之前尝试的layoutMargins会影响整个导航栏布局（包括搜索栏），正确做法是直接调整返回按钮图标的内边距：

// 在上述applyAppearance方法中，给backButtonAppearance添加以下设置
backButtonAppearance.normal.imageInsets = UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 0)

该设置仅作用于返回箭头，不会干扰其他导航栏元素。

3. 替换返回按钮图标（保留原生手势） #

你之前的设置无效，多是因为图片渲染模式或设置时机问题。以下是两种有效实现方式：

全局设置（所有导航栏生效） #

在App启动阶段（如AppDelegate的application(_:didFinishLaunchingWithOptions:)或SceneDelegate的scene(_:willConnectTo:options:)）执行：

if let backImage = UIImage(systemName: "chevron.left")?.withRenderingMode(.alwaysTemplate) {
    UINavigationBar.appearance().backIndicatorImage = backImage
    UINavigationBar.appearance().backIndicatorTransitionMaskImage = backImage
}

使用.alwaysTemplate模式可让图标继承导航栏的tintColor，保证颜色统一。

局部设置（单个导航栏生效） #

在applyAppearance方法中添加：

if let backImage = UIImage(named: "custom-back-arrow")?.withRenderingMode(.alwaysTemplate) {
    appearance.setBackIndicatorImage(backImage, transitionMaskImage: backImage)
}

注意：确保图片资源存在，且设置时机在导航控制器初始化完成、push视图控制器之前。

完整整合代码 #

extension UINavigationBar {
    func applyAppearance(backgroundColor: UIColor, textColor: UIColor) {
        let appearance = UINavigationBarAppearance()
        appearance.configureWithOpaqueBackground()
        appearance.backgroundColor = backgroundColor
        appearance.shadowColor = .clear
        appearance.titleTextAttributes = [.foregroundColor: textColor]
        
        // 移除返回按钮文字
        let backButtonAppearance = UIBarButtonItemAppearance(style: .plain)
        backButtonAppearance.normal.titlePositionAdjustment = UIOffset(horizontal: -1000, vertical: 0)
        
        // 调整返回箭头左侧边距
        backButtonAppearance.normal.imageInsets = UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 0)
        
        appearance.backButtonAppearance = backButtonAppearance
        
        // 替换返回按钮图标（可选局部设置）
        if let backImage = UIImage(systemName: "chevron.left")?.withRenderingMode(.alwaysTemplate) {
            appearance.setBackIndicatorImage(backImage, transitionMaskImage: backImage)
        }
        
        tintColor = textColor
        standardAppearance = appearance
        scrollEdgeAppearance = appearance
        compactScrollEdgeAppearance = appearance
    }
}

关键注意事项 #

• 必须同步设置standardAppearance、scrollEdgeAppearance、compactScrollEdgeAppearance，避免不同滚动状态下样式失效。
• 使用.alwaysTemplate渲染模式，确保自定义图标的颜色与导航栏tintColor一致。
• 全程基于原生导航栏API实现，完全保留原生swipe-to-pop手势，无需自定义按钮。

内容的提问来源于stack exchange，提问作者Shawn Frank