使用 UIBarButtonItemAppearance 同时具有系统和自定义后退按钮图像

Question

我是第一次使用 UIBarButtonItemAppearance，我对如何为后退按钮放置自定义图像感到困惑。

我是这样做的：

private func createBarButtonAppearence(_ color: UIColor, textColor: UIColor)  -> UINavigationBarAppearance {
        let appearance = UINavigationBarAppearance()
        appearance.titleTextAttributes = [.foregroundColor: textColor]
        appearance.largeTitleTextAttributes = [.foregroundColor: textColor]
        appearance.configureWithOpaqueBackground()
        appearance.backgroundColor = color
        
        let back = UIBarButtonItemAppearance()
        back.normal.backgroundImage = UIImage(named: "white_back_arrow")
        appearance.backButtonAppearance = back
        return appearance
    }

这成功地将 "white_back_arrow" 图像作为后退按钮，但它也保留了原始的 iOS 后退按钮图像，如图所示：

如何避免这种行为？

Answer 1

您正在设置按钮的背景图片。这不会改变 按钮的 图像。

这样试试：

private func createBarButtonAppearence(_ color: UIColor, textColor: UIColor)  -> UINavigationBarAppearance {
    let appearance = UINavigationBarAppearance()
    appearance.titleTextAttributes = [.foregroundColor: textColor]
    appearance.largeTitleTextAttributes = [.foregroundColor: textColor]
    appearance.configureWithOpaqueBackground()
    appearance.backgroundColor = color
    
    // do this
    if let img = UIImage(systemName: "white_back_arrow") {
        appearance.setBackIndicatorImage(img, transitionMaskImage: img)
    }

    // don't do this:
    //let back = UIBarButtonItemAppearance()
    //back.normal.backgroundImage = UIImage(named: "white_back_arrow")
    //appearance.backButtonAppearance = back
    
    return appearance
}

使用 UIBarButtonItemAppearance 同时具有系统和自定义后退按钮图像

Using UIBarButtonItemAppearance have both the system and the custom back button images

uinavigationbar

ios

swift

uinavigationbarappearance

ios15