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
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
其他回答
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。
为了补充上面托马斯·C的回答，有时只放一个空格是行不通的，你必须不断地添加空格。
当你看到“导航项”下的“栏按钮项-”时，你就知道你成功了。这是在文档大纲(编辑器->显示文档大纲)。一旦你看到上面的图片，你可以删除一些空格，看看它是否仍然有效。
// add left bar button item
try this code:
- (void)viewDidLoad
{
[super viewDidLoad];
UIImage* image_back = [UIImage imageNamed:@"your_leftarrowImage.png"];
CGRect backframe = CGRectMake(250, 9, 15,21);
UIButton *backbutton = [[UIButton alloc] initWithFrame:backframe];
[backbutton setBackgroundImage:image_back forState:UIControlStateNormal];
[backbutton addTarget:self action:@selector(Btn_back:)
forControlEvents:UIControlEventTouchUpInside];
[backbutton setShowsTouchWhenHighlighted:YES];
UIBarButtonItem *backbarbutton =[[UIBarButtonItem alloc] initWithCustomView:backbutton];
self.navigationItem.leftBarButtonItem=backbarbutton;
[backbutton release];
}
-(IBAction)Btn_back:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
// Custom initialization
self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}
return self;
}
就像Kyle Begeman所做的那样，在根视图控制器中添加上面的代码。所有子视图控制器都会被应用。此外，在initWithCoder:方法中添加这个，你可以在xib、storyboard或基于代码的方法中应用根视图控制器的样式。
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)
