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
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];
}
改变backItem。title = "" to使用topItem。标题= "" 设置navigationItem。hidesBackButton = true & navigationItem。leftBarButtonItem将失去后退手势 记住，我们必须创建2个back映像的实例
我的解决方案将改变图像和保持后面的手势:
navigationController?.navigationBar.backIndicatorImage = UIImage(named: "back")
navigationController?.navigationBar.backIndicatorTransitionMaskImage = UIImage(named: "back")
navigationController?.navigationBar.topItem?.title = ""
你可以用这个。这对我来说是完美的，只是添加一个UIButton作为UIBarButtonItem的定制视图。
试试下面的代码
self.navigationItem.leftBarButtonItem=[self backButton];
- (UIBarButtonItem *)backButton
{
UIImage *image = [UIImage imageNamed:@"back-btn.png"];
CGRect buttonFrame = CGRectMake(0, 0, image.size.width, image.size.height);
UIButton *button = [[UIButton alloc] initWithFrame:buttonFrame];
[button addTarget:self action:@selector(backButtonPressed) forControlEvents:UIControlEventTouchUpInside];
[button setImage:image forState:UIControlStateNormal];
UIBarButtonItem *item= [[UIBarButtonItem alloc] initWithCustomView:button];
return item;
}
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
}
}
}
}
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];
