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
其实很简单，我是这么做的:
Objective - C
// Set this in every view controller so that the back button displays back instead of the root view controller name
self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
斯威夫特2
self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)
斯威夫特3
self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)
把这一行放到推送到堆栈(前一个视图控制器)的视图控制器中。新按下的视图控制器返回按钮现在将显示你为initWithTitle所放的任何东西，在本例中是一个空字符串。
其他回答
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
你不能以你想要的方式访问导航backButtonItem，你需要创建自己的返回按钮，如下所示:
- (void)loadView
{
[super loadView];
UIButton *backButton = [[UIButton alloc] initWithFrame: CGRectMake(0, 0, 44.0f, 30.0f)];
[backButton setImage:[UIImage imageNamed:@"back.png"] forState:UIControlStateNormal];
[backButton addTarget:self action:@selector(popVC) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
}
当然了:
- (void) popVC{
[self.navigationController popViewControllerAnimated:YES];
}
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
设置返回按钮项目标题为空字符串。
[自我navigationController navigationBar。backItem setTitle: @“”);
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。
