自定义rightBarButtonItem消失

我在导航栏中有一个自定义 rightBarButtomItem 的奇怪错误。我有一个 TabBar 应用程序。如果应用程序已加载，按钮将显示正确。如果我单击选项卡，按钮将继续显示。如果我返回到已显示的选项卡之一，该按钮就会消失。最后，该按钮仅随机显示在其中一个选项卡中。

如果我以编程方式设置标准 rightBarButtomItem，我的代码可以完美运行。但不适用于自定义图形。如果 ChildViewController 被按下并弹出，该按钮会再次出现。看起来它仍然存在，但不可见！

我认为我在自定义 TabBarViewController 中对 shareRightButton 的引用是错误的！

有人可以帮忙吗？

自定义TabBarController.h

   #import <UIKit/UIKit.h>
    #import "EZBadgeView.h"

    @interface CustomTabBarController : UITabBarController
    {
        EZBadgeView *badgeView;
        UIButton *btn;
        UIImage *rightBarButtonItemImage;
        UIImage *rightBarButtonItemImageTapped;
        UIImage *rightBarButtonItemImageSelected;
    }

    @property (nonatomic, strong) UIBarButtonItem *sharedRightButton;
    @property (nonatomic, strong) EZBadgeView *badgeView;
    @property(nonatomic, strong) UIButton *btn;
    @property(nonatomic, strong) UIImage *rightBarButtonItemImage;
    @property(nonatomic, strong) UIImage *rightBarButtonItemImageTapped;
    @property(nonatomic, strong) UIImage *rightBarButtonItemImageSelected;

    @end

自定义TabBarController.m

    #import "CustomTabBarController.h"

    @interface CustomTabBarController ()

    @end

    @implementation CustomTabBarController

    @synthesize sharedRightButton, badgeView, btn, rightBarButtonItemImage, rightBarButtonItemImageSelected, rightBarButtonItemImageTapped;

    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
    {
        self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
        if (self) {
            // Custom initialization
        }
        return self;
    }

    - (void)viewDidLoad
    {
        [super viewDidLoad];

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateBadgeNumber:) name:@"updateBadgeNumber" object:nil];

        if (self.badgeView && self.badgeView.superview)
        {
            [self.badgeView removeFromSuperview];
        }
        self.badgeView = [[EZBadgeView alloc] init];
        CGRect badgeFrame = self.badgeView.frame;
        badgeFrame.origin.x = 31.0f;
        badgeFrame.origin.y = -6.0f;
        badgeFrame = CGRectIntegral(badgeFrame);
        self.badgeView.frame = badgeFrame;
        self.badgeView.badgeBackgroundColor = [self colorWithRGBHex:kRed withAlpha:1.0f];
        self.badgeView.userInteractionEnabled = NO;
        self.badgeView.badgeTextFont = [UIFont fontWithName:@"BrownStd-Bold" size:12];
        self.badgeView.shouldShowGradient = NO;
        self.badgeView.shouldShowShine = NO;

        // Allocate UIButton
        self.btn = [UIButton  buttonWithType:UIButtonTypeCustom];
        self.btn.frame = CGRectMake(0, 0, 46, 30);

        self.rightBarButtonItemImage = [UIImage imageNamed:@"button_mixer.png"];
        [self.btn setBackgroundImage:rightBarButtonItemImage forState:UIControlStateNormal];
        self.rightBarButtonItemImageTapped = [UIImage imageNamed:@"button_mixer_pressed.png"];
        [self.btn setBackgroundImage:rightBarButtonItemImageTapped forState:UIControlStateHighlighted];
        self.rightBarButtonItemImageSelected = [UIImage imageNamed:@"button_mixer_active.png"];
        [self.btn setBackgroundImage:rightBarButtonItemImageSelected forState:UIControlStateSelected];

        [self.btn addTarget:self action:@selector(clickedTest:) forControlEvents:UIControlEventTouchUpInside];
        [self.btn setBackgroundColor:[UIColor clearColor]];
        [self.btn addSubview:self.badgeView]; //Add NKNumberBadgeView as a subview on UIButton

        // Initialize UIBarbuttonitem...
         self.sharedRightButton = [[UIBarButtonItem alloc] initWithCustomView:btn];
         self.badgeView.badgeValue = @"0";
         self.badgeView.hidden = YES;
    }

    - (void)updateBadgeNumber:(NSMutableArray *)soundArray
    {
        self.badgeView.badgeValue = [NSString stringWithFormat:@"%i",[soundArray count]];
        self.badgeView.hidden = ([soundArray count] == 0);
    }

    - (void)clickedTest:(id)sender
    {
        NSLog(@"%s", __FUNCTION__);
    }

    - (void)didReceiveMemoryWarning
    {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }

    - (UIColor *)colorWithRGBHex:(UInt32)hex withAlpha:(float)alpha
    {
        int r = (hex >> 16) & 0xFF;
        int g = (hex >> 8) & 0xFF;
        int b = (hex) & 0xFF;

        return [UIColor colorWithRed:r / 255.0f
                               green:g / 255.0f
                                blue:b / 255.0f
                               alpha:alpha];
    }

    @end

我在每个视图中设置这样的按钮：

@implementation MyVC

@synthesize tabBarController;

    - (void)viewDidLoad
    {
        //NSLog(@"begin: %s", __FUNCTION__);
        [super viewDidLoad];


         // right bar button from custom tabbarcontroller
        self.tabBarController = [[CustomTabBarController alloc] init];
        self.navigationItem.rightBarButtonItem = self.tabBarController.sharedRightButton;

}

让我印象深刻的是，创造了一个新的CustomTabBarController对于每个视图控制器来说都是根本错误的，特别是如果它是为了解决右键没有出现的问题。问题是您正在创建新的虚拟选项卡栏控制器，更糟糕的是，丢失了对视图控制器的真实选项卡栏控制器的引用。

您的解决方案触及了问题的核心，那就是，因为您正在为按钮添加子视图，即创建UIBarButtonItem with initWithCustomView等，您不能与多个导航控制器共享按钮。如果您创建一个简单的，则共享的公共右栏按钮将起作用UIBarButtonItem with initWithTitle（或其他类似的简单变体），但如果您使用按钮的自定义视图来执行此操作，则它不起作用。

正确的解决方案是创建一个新的UIBarButtonItem具有您需要的行为和外观的实例。然后，任何需要该栏按钮项的视图控制器都可以创建该按钮的实例。于是，新习俗RightBarButtonItem可能看起来像：

RightBarButtonItem.h：

@interface RightBarButtonItem : UIBarButtonItem

- (id)initWithTarget:(id)target action:(SEL)action;

@end

RightBarButtonItem.m：

@interface RightBarButtonItem ()
@property (nonatomic, strong) EZBadgeView *badgeView;
@end

@implementation RightBarButtonItem

- (id)initWithTarget:(id)target action:(SEL)action
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(0, 0, 46, 30);

    self = [super initWithCustomView:button];

    if (self)
    {
        _badgeView = [[EZBadgeView alloc] init];
        CGRect badgeFrame = self.badgeView.frame;
        badgeFrame.origin.x = 31.0f;
        badgeFrame.origin.y = -6.0f;
        badgeFrame = CGRectIntegral(badgeFrame);
        _badgeView.frame = badgeFrame;
        _badgeView.badgeBackgroundColor = [self colorWithRGBHex:kRed withAlpha:1.0f];
        _badgeView.userInteractionEnabled = NO;
        _badgeView.badgeTextFont = [UIFont fontWithName:@"BrownStd-Bold" size:12];
        _badgeView.shouldShowGradient = NO;
        _badgeView.shouldShowShine = NO;

        [button setBackgroundImage:[UIImage imageNamed:@"button_mixer.png"]         forState:UIControlStateNormal];
        [button setBackgroundImage:[UIImage imageNamed:@"button_mixer_pressed.png"] forState:UIControlStateHighlighted];
        [button setBackgroundImage:[UIImage imageNamed:@"button_mixer_active.png"]  forState:UIControlStateSelected];

        [button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
        [button setBackgroundColor:[UIColor clearColor]];
        [button addSubview:_badgeView]; //Add NKNumberBadgeView as a subview on UIButton

        _badgeView.badgeValue = @"0";
        _badgeView.hidden = YES;

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(updateBadgeNumber:)
                                                     name:@"updateBadgeNumber"
                                                   object:nil];
    }

    return self;
}

- (void)dealloc
{
    // don't forget to have mechanism to remove the observer when this button is deallocated

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:@"updateBadgeNumber"
                                                  object:nil];
}

- (void)updateBadgeNumber:(NSMutableArray *)soundArray
{
    self.badgeView.badgeValue = [NSString stringWithFormat:@"%i",[soundArray count]];
    self.badgeView.hidden = ([soundArray count] == 0);
}

- (UIColor *)colorWithRGBHex:(UInt32)hex withAlpha:(float)alpha
{
    int r = (hex >> 16) & 0xFF;
    int g = (hex >> 8) & 0xFF;
    int b = (hex) & 0xFF;

    return [UIColor colorWithRed:r / 255.0f
                           green:g / 255.0f
                            blue:b / 255.0f
                           alpha:alpha];
}

@end

然后，CustomTabBarController大大简化了：

自定义TabBarController.h：

@interface CustomTabBarController : UITabBarController

- (UIBarButtonItem *)rightBarButton;

@end

自定义TabBarController.m：

#import "RightBarButtonItem.h"

@implementation CustomTabBarController

- (UIBarButtonItem *)rightBarButton
{
    return [[RightBarButtonItem alloc] initWithTarget:self
                                               action:@selector(clickedTest:)];
}

- (void)clickedTest:(id)sender
{
    NSLog(@"%s", __FUNCTION__);
}

@end

最后，添加到选项卡栏控制器的所有视图控制器都可以简单地执行以下操作：

- (void)viewDidLoad
{
    [super viewDidLoad];

    CustomTabBarController *tabBarController = (id)self.tabBarController;

    self.navigationItem.rightBarButtonItem = [tabBarController rightBarButton];
}

所有这些都实现了您提出的解决方案的关键部分，即确保我们拥有右侧栏按钮项目的唯一实例，但不存在创建冗余选项卡栏控制器的问题。