我如何自定义导航返回按钮在iOS 7及以上没有标题?(即只使用箭头)
self.navigationItem.leftBarButtonItem = self.editButtonItem;
我只是想知道它们是否有self。backbuttonitem;
OR
像这样的东西?
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemBACK
target:self action:@selector(back)];
当前回答
我写了一个扩展，使这更容易:
extension UIViewController {
/// Convenience for setting the back button, which will be used on any view controller that this one pushes onto the stack
@objc var backButtonTitle: String? {
get {
return navigationItem.backBarButtonItem?.title
}
set {
if let existingBackBarButtonItem = navigationItem.backBarButtonItem {
existingBackBarButtonItem.title = newValue
}
else {
let newNavigationItem = UIBarButtonItem(title: newValue, style:.plain, target: nil, action: nil)
navigationItem.backBarButtonItem = newNavigationItem
}
}
}
}
其他回答
你可以把这个类别放在AppDelegate中。m文件。 移除UINavigation中所有默认后退按钮的文本。只有箭头“<”或设置自定义图像，如果你需要。
objective - c:
...
@end
@implementation UINavigationItem (Extension)
- (UIBarButtonItem *)backBarButtonItem {
return [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}
@end
斯威夫特4
对于那些希望创建自定义后退按钮以及删除它们的标题的人，请在视图控制器中使用下面的一段代码来推送新的按钮:
self.navigationController?.navigationBar.backIndicatorImage = UIImage(named: "close")
self.navigationController?.navigationBar.backIndicatorTransitionMaskImage = UIImage(named: "close")
self.navigationItem?.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)
为了更普遍的使用，请执行以下操作:
Create a universal function as follows: func addCustomizedBackBtn(navigationController: UINavigationController?, navigationItem: UINavigationItem?) { navigationController?.navigationBar.backIndicatorImage = UIImage(named: "close") navigationController?.navigationBar.backIndicatorTransitionMaskImage = UIImage(named: "close") navigationItem?.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil) } Then use it in the view controllers as follows: addCustomizedBackBtn(navigationController: self.navigationController, navigationItem: self.navigationItem)
所有的答案都不能解决问题。在每个视图控制器中设置后退按钮标题，并且添加偏移量仍然会使下一个视图控制器标题向右移动，这是不可接受的。
这里是使用方法swizzling的方法，只需创建新的扩展UINavigationItem
import UIKit
extension UINavigationItem {
public override class func initialize() {
struct Static {
static var token: dispatch_once_t = 0
}
// make sure this isn't a subclass
if self !== UINavigationItem.self {
return
}
dispatch_once(&Static.token) {
let originalSelector = Selector("backBarButtonItem")
let swizzledSelector = #selector(UINavigationItem.noTitleBackBarButtonItem)
let originalMethod = class_getInstanceMethod(self, originalSelector)
let swizzledMethod = class_getInstanceMethod(self, swizzledSelector)
let didAddMethod = class_addMethod(self, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))
if didAddMethod {
class_replaceMethod(self, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod))
} else {
method_exchangeImplementations(originalMethod, swizzledMethod)
}
}
}
// MARK: - Method Swizzling
struct AssociatedKeys {
static var ArrowBackButtonKey = "noTitleArrowBackButtonKey"
}
func noTitleBackBarButtonItem() -> UIBarButtonItem? {
if let item = self.noTitleBackBarButtonItem() {
return item
}
if let item = objc_getAssociatedObject(self, &AssociatedKeys.ArrowBackButtonKey) as? UIBarButtonItem {
return item
} else {
let newItem = UIBarButtonItem(title: " ", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)
objc_setAssociatedObject(self, &AssociatedKeys.ArrowBackButtonKey, newItem as UIBarButtonItem?, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
return newItem
}
}
}
iOS6的简单破解也适用于iOS7:
[UIBarButtonItem.appearance setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60) forBarMetrics:UIBarMetricsDefault];
编辑: 不要使用这种方法。详情见评论。
如果你设置了导航栏的tintColor，添加一个没有标题的自定义后退按钮图像，该图像的tintColor将反映图像的颜色。请点击苹果文档链接。
https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/UIKitUICatalog/index.html#//apple_ref/doc/uid/TP40012857-UIView-SW7
UINavigationItem *navItem = [[UINavigationItem alloc] init];
navBar.tintColor = self.tintColor;
UIImage *myImage = [UIImage imageNamed:@"left_arrow.png"];
myImage = [myImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithImage:myImage style:UIBarButtonItemStylePlain target:self action:@selector(cancelButtonFunction:)];
navItem.leftBarButtonItem = leftButton;
navBar.items = @[ navItem ];
