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)];
虽然Kyle Begeman的回答完全做到了,但在每个视图控制器中都使用这种代码是相当烦人的。我最终得到了一个简单的UINavigationItem类别。小心,这里有龙!抱歉,我的意思是:
#import <objc/runtime.h>
@implementation UINavigationItem (ArrowBackButton)
static char kArrowBackButtonKey;
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Method m1 = class_getInstanceMethod(self, @selector(backBarButtonItem));
Method m2 = class_getInstanceMethod(self, @selector(arrowBackButton_backBarButtonItem));
method_exchangeImplementations(m1, m2);
});
}
- (UIBarButtonItem *)arrowBackButton_backBarButtonItem {
UIBarButtonItem *item = [self arrowBackButton_backBarButtonItem];
if (item) {
return item;
}
item = objc_getAssociatedObject(self, &kArrowBackButtonKey);
if (!item) {
item = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleBordered target:nil action:NULL];
objc_setAssociatedObject(self, &kArrowBackButtonKey, item, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
return item;
}
@end
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
}
}
}
iOS7有新的界面规则,所以当你推送一个UIView时,最好至少保留后退箭头。
通过编程方式更改“返回”文本非常容易。只需要在推送视图之前添加这段代码(如果你使用的是StoryBoards,可以使用prepareForSegue):
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
self.navigationItem.backBarButtonItem=[[UIBarButtonItem alloc] initWithTitle:@"NEW TITLE" style:UIBarButtonItemStylePlain target:nil action:nil];
}
这将改变默认的“后退”文本,但将保持iOS7风格的后退箭头。
你也可以在推送视图之前改变后退箭头的颜色:
- (void)viewDidLoad{
//NavBar background color:
self.navigationController.navigationBar.barTintColor=[UIColor redColor];
//NavBar tint color for elements:
self.navigationController.navigationBar.tintColor=[UIColor whiteColor];
}
希望这对你有所帮助!
只用一张图片!
OBJ - c:
- (void)viewDidLoad {
[super viewDidLoad];
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"Icon-Back"]
style:UIBarButtonItemStylePlain
target:self.navigationController
action:@selector(popViewControllerAnimated:)];
self.navigationItem.leftBarButtonItem = backButton;
}
斯威夫特4:
let backBTN = UIBarButtonItem(image: UIImage(named: "Back"),
style: .plain,
target: navigationController,
action: #selector(UINavigationController.popViewController(animated:)))
navigationItem.leftBarButtonItem = backBTN
navigationController?.interactivePopGestureRecognizer?.delegate = self
Icon-Back.png
Icon-Back@2x.png
Icon-Back@3x.png