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
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
}
}
}
其他回答
我找到了一个简单的方法，让我的返回按钮与iOS单箭头。
让我们假设你有一个导航控制器从ViewB到ViewA。在IB中，选择ViewA的导航栏，你应该看到这些选项:标题，提示和返回按钮。
ViewA导航栏选项
诀窍是在前一个视图控制器(view A)的选项中选择你的命运视图控制器返回按钮的标题(ViewB)。如果你不填写“返回按钮”选项，iOS将自动将标题“返回”加上前一个视图控制器的标题。因此，您需要用一个空格填充这个选项。
在“返回按钮”选项中填充空格
结果:
我在viewDidLoad中应用了以下代码，它可以工作:
// this will set the back button title
self.navigationController.navigationBar.topItem.title = @"Test";
// this line set the back button and default icon color
//[[self.navigationController.navigationBar.subviews lastObject] setTintColor:[UIColor blackColor]];
this line change the back default icon to your custom icon
[[self.navigationController.navigationBar.subviews lastObject] setTintColor:[UIColor colorWithPatternImage:[UIImage imageNamed:@"menuicon"]]];
只是更新我使用矢量图标
你可以子类化UINavigationController，将自己设置为委托，并在委托方法navigationController:willShowViewController:animated中设置backBarButtonItem:
@interface Custom_NavigationController : UINavigationController <UINavigationControllerDelegate>
@end
@implementation Custom_NavigationController
- (void)viewDidLoad
{
[super viewDidLoad];
self.delegate = self;
}
#pragma mark - UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
viewController.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}
@end
我从iOS 5开始就一直在使用这个解决方案，没有任何问题。我在视图控制器中调用了一个实用函数。你需要在viewDidLoad或之后的任何点中做。
void updateBackButtonTextForViewController(UIViewController *viewController, NSString *text)
{
if(! viewController.navigationItem.backBarButtonItem)
{
viewController.navigationItem.backBarButtonItem =
[[UIBarButtonItem alloc] initWithTitle:text
style:UIBarButtonItemStylePlain
target:nil action:nil];
}
else
{
viewController.navigationItem.backBarButtonItem.title = text;
}
}
在某些情况下，导航项可能已经存在，在其他情况下需要创建它。这在不影响导航项标题的情况下解释了这两种情况。它允许你通过简单地传入@""来删除标题。
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
}
}
}
