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
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];
}
其他回答
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 = ""
将标题设置为空
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleDone target:self action:@selector(handleBack:)];
[backButton setTintColor:Color_WHITE];
[self.navigationItem setBackBarButtonItem:backButton];
换回图像
UIImage *backImg = [[UIImage imageNamed:@"ic_back_white"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
[UINavigationBar appearance].backIndicatorImage = backImg;
[UINavigationBar appearance].backIndicatorTransitionMaskImage = backImg;
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
目标: 自定义UINavigationBar上的所有后退按钮为白色图标
步骤: 1. 在AppDelete的didFinishLaunchingWithOptions方法中:
UIImage *backBtnIcon = [UIImage imageNamed:@"navBackBtn"];
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
[UINavigationBar appearance].tintColor = [UIColor whiteColor];
[UINavigationBar appearance].backIndicatorImage = backBtnIcon;
[UINavigationBar appearance].backIndicatorTransitionMaskImage = backBtnIcon;
}else{
UIImage *backButtonImage = [backBtnIcon resizableImageWithCapInsets:UIEdgeInsetsMake(0, backBtnIcon.size.width - 1, 0, 0)];
[[UIBarButtonItem appearance] setBackButtonBackgroundImage:backButtonImage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -backButtonImage.size.height*2) forBarMetrics:UIBarMetricsDefault];
}
2.在普通超级ViewController类的viewDidLoad方法中:
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
UIBarButtonItem *backItem = [[UIBarButtonItem alloc] initWithTitle:@""
style:UIBarButtonItemStylePlain
target:nil
action:nil];
[self.navigationItem setBackBarButtonItem:backItem];
}else{
//do nothing
}
你不需要做什么。你可以通过故事板本身来实现同样的效果。
只要到根导航控制器，并给一个空间。记住，返回按钮不是指向你想要的没有标题的控制器，而是指向根导航控制器。
