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)];
编辑:2014-04-09:当我获得声誉时,我感到抱歉,因为我不再使用这个技巧了。我推荐凯尔的答案。还要注意self。navigationitem。backbarbuttonitem的self不是返回按钮显示的视图控制器,而是要返回的前一个视图控制器。
如果之前的视图控制器不需要标题文本,只需用空白字符串填充标题;
self.navigationItem.title = @"";
[self.navigationController pushViewController:viewController animated:YES];
这将防止在被推送的视图控制器上显示带雪佛龙的“返回”。
编辑:即使你使用非空白标题文本,在viewWillAppear中设置前一个视图控制器的标题:除了标题可以闪烁在闪烁时,视图控制器弹出。我认为“推特应用程序”似乎做了更微妙的hack来避免闪烁。
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
}
}
}
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 ];