我正在尝试在我的应用中更改导航控制器后退按钮的默认外观。
我想使用和图像（图标）并删除“后退”文本。 此代码在整个按钮上拉伸图像，但不删除按钮标题。
let backImg: UIImage = UIImage(named: "icon_back")!
UIBarButtonItem.appearance().setBackButtonBackgroundImage(backImg, for: .normal, barMetrics: .default)
如何做的建议是在AppDelegate（didFinishLaunchingWithOptions）中？
答案 0 :(得分：1)
简单的方法就是为您的项目创建一个BaseViewController，该UIViewController派生自BaseViewController。您可以在custom leftBarButton中使用常用方法在每个viewController中创建derived from this BaseViewController。项目中剩余的viewController应为class BaseViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
createLeftBarButton(image: #Pass image here#, width: #Pass width of your image view#) // Create custom back bar button.
}
/**Create cutom back bar button*/
func createLeftBarButton(image: UIImage?, width: CGFloat) {
let backButton: UIButton = UIButton(frame: CGRect(x: 0, y: 0, width: width, height: 50))
backButton.imageView?.contentMode = .scaleAspectFill
backButton.imageView?.bounds = CGRect(x: 0, y: 0, width: width, height: width)
backButton.setImage(image, for: .normal)
backButton.setImage(image, for: .highlighted)
backButton.addTarget(self, action: #selector(leftBarButtonItemPressed(_:)), for: .touchUpInside)
let leftItem: UIBarButtonItem = UIBarButtonItem(customView: backButton)
navigationItem.leftBarButtonItem = leftItem
}
/**Custom back bar button pressed. So handle here*/
func leftBarButtonItemPressed(_ sender: UIButton) {
view.endEditing(true) // End editing if any.
if isViewControllerPresented() { // Check view controller is presented or pushed
dismiss(animated: true, completion: nil) // Dismiss ViewController if presented
} else {
_ = navigationController?.popViewController(animated: true) // Pop ViewController if pushed
}
}
/**To check whether view controller is presented or pushed.*/
func isViewControllerPresented() -> Bool {
if self.presentingViewController?.presentedViewController == self {
return true
}
if (self.navigationController != nil && self.navigationController?.presentingViewController?.presentedViewController == self.navigationController) && self.navigationController?.viewControllers.count == 1 {
return true
}
if self.tabBarController?.presentingViewController is UITabBarController {
return true
}
return false
}
}
// Sub class your remaining viewControllers like this.
class FirstViewController: BaseViewController {
override func viewDidLoad() {
super.viewDidLoad() // When calling this super method, the custom back bar button will be created for you
}
}
，
{{1}}
感谢。
答案 1 :(得分：0)
您可以通过设置navigationItem＆＃39; BackButtonBackgroundImage;
您也可以设置全局效果的外观：
let item = UIBarButtonItem.appearance(whenContainedInInstancesOf: [UINavigationBar.self])
item.setBackButtonBackgroundVerticalPositionAdjustment(-10, for: .default) item.setBackButtonBackgroundImage(youImage, for: .normal, barMetrics: .default)
删除后面的标题，你可以这样做：
@implementation UINavigationItem (BackItem)
-(UIBarButtonItem *)backBarButtonItem {
UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithTitle:@" " style:UIBarButtonItemStylePlain target:nil action:nil];
item.tintColor = [UIColor darkGrayColor];
return item;
}
@end