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
我写了一个扩展，使这更容易:
extension UIViewController {
/// Convenience for setting the back button, which will be used on any view controller that this one pushes onto the stack
@objc var backButtonTitle: String? {
get {
return navigationItem.backBarButtonItem?.title
}
set {
if let existingBackBarButtonItem = navigationItem.backBarButtonItem {
existingBackBarButtonItem.title = newValue
}
else {
let newNavigationItem = UIBarButtonItem(title: newValue, style:.plain, target: nil, action: nil)
navigationItem.backBarButtonItem = newNavigationItem
}
}
}
}
其他回答
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
这在iOS6和ios7上都很有效
Xamarin (c#)选项
var buttonStyleItems = UIBarButtonItem.AppearanceWhenContainedIn(typeof(SettingsNavigationController));
buttonStyleItems.SetBackButtonTitlePositionAdjustment(new UIOffset(-1000, -1000), UIBarMetrics.Default);
objective - c选项
[[UIBarButtonItem外观]setBackButtonTitlePositionAdjustment:UIOffsetMake(-1000， -1000) forBarMetrics:UIBarMetricsDefault];
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!
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
在你的第一个ViewController的prepareForSegue:方法中，你设置视图标题为@""，所以当下一个视图被推送时，它将显示前一个ViewController标题为@""。
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
self.navigationItem.title = @" ";
}
唯一的问题是，当你点击返回按钮时，你之前的视图将没有标题，所以你可以在viewWillAppear上再次添加它:
-(void)viewWillAppear:(BOOL)animated{
self.navigationItem.title = @"First View Title";
}
我不太喜欢这个解决方案，但它是可行的，我没有找到其他方法来做到这一点。
