第二篇、Swift_自定义 tabbar 的 badgeValue显示样式

使用方式：

class BKTabBarController: UITabBarController {

override func viewDidLoad() {
super.viewDidLoad()

self.addCustomTabbar()

}

func addCustomTabbar()  {

let newTabbar                       = BKTabbar(frame: self.tabBar.frame)
newTabbar.items                     = self.tabBar.items
newTabbar.badgeValueTextColor       = UIColor.black
newTabbar.badgeValueBackgroundColor = UIColor.yellow
self.setValue(newTabbar, forKey: "tabBar")

}

}

设置数值的方式：

self.tabBarItem.badgeValue = "100"

通过 UIViewControler 的 tabBarItem.badgeValue 属性设置 badgeValue的值 , 跟系统的 badgeValue 设置方式一致,只是屏蔽了系统的实现方法,改成自定义 badgeValue 的显示样式

0.UITabBarItem+Extension

#import <UIKit/UIKit.h>

@interface UITabBarItem (Extension)

/**
*  tabBarItem 的 tag
*/
@property (nonatomic,assign) NSInteger index;

/**
*   自定义 tabBar 的 badgeValue
*/
@property (nonatomic,copy,nullable) NSString *customBadgeValue;

@end

#import "UITabBarItem+Extension.h"
#import <objc/runtime.h>

static NSString *const kItemTagKey     = @"tags";

static NSString *const kItemBadgeValue = @"badgeValue";

@implementation UITabBarItem (Extension)

- (void)setIndex:(NSInteger)index {

NSNumber *number =  [NSNumber numberWithInteger:index];
objc_setAssociatedObject(self, &kItemTagKey, number, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

}

- (NSInteger)index {

NSNumber *number = (NSNumber *)objc_getAssociatedObject(self, &kItemTagKey);
return number.integerValue;

}

- (void)setCustomBadgeValue:(NSString *)customBadgeValue {

objc_setAssociatedObject(self, &kItemBadgeValue, customBadgeValue, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

[[NSNotificationCenter defaultCenter] postNotificationName:@"TabbarBadgeValueChange" object:self];

}

- (NSString *)customBadgeValue {

NSString *value = (NSString *)objc_getAssociatedObject(self, &kItemBadgeValue);

return value;
}

- (void)setBadgeValue:(NSString *)badgeValue {

self.customBadgeValue   = badgeValue;
}

@end

1.自定义的tabbar

#import <UIKit/UIKit.h>

/**
*  自定义 tabBar 解决了 badgeValue 显示问题
*/
@interface BKTabbar : UITabBar

/**
*  自定义 badgeValue 的背景色
*/
@property (nonatomic,strong,nullable) UIColor *badgeValueBackgroundColor;
/**
*  自定义 badgeValue 的文字颜色
*/
@property (nonatomic,strong,nullable) UIColor *badgeValueTextColor;

@end

#import "BKTabbar.h"
#import "UITabBarItem+Extension.h"

@interface BKTabbar ()

@property (nonatomic,strong,nullable) NSMutableDictionary *badgeValuesDic;

@end

@implementation BKTabbar

- (NSMutableDictionary *)badgeValuesDic {
if (!_badgeValuesDic) {
_badgeValuesDic = [NSMutableDictionary dictionary];
}
return _badgeValuesDic;
}

- (void)layoutSubviews {

[super layoutSubviews];

NSInteger indexTag        = 1000;
NSMutableArray *tempArray = [NSMutableArray array];

// 便利 tabbar 所有子视图
for (UIView *sub in self.subviews) {

if ([sub isKindOfClass:NSClassFromString(@"UITabBarButton")]) {

if ([tempArray containsObject:sub]) continue;
[tempArray addObject:sub];

}
}
// 临时数组保存四个按钮
[tempArray sortUsingComparator:^NSComparisonResult(UIButton *btn1, UIButton *btn2) {

NSNumber *number1 = [NSNumber numberWithFloat:btn1.frame.origin.x];
NSNumber *number2 = [NSNumber numberWithFloat:btn2.frame.origin.x];

return [number1 compare :number2];

}];

// 便利数组给 badgeValue 赋值
for (UIButton *button in tempArray) {

NSString *key       = [NSString stringWithFormat:@"%@",@(indexTag)];
CGFloat buttonWidth = button.frame.size.width;
UILabel *oldLabel   = [button viewWithTag:key.integerValue];

// 先找重用 不存在就创建一个
if (!oldLabel) {

UILabel *label            = [[UILabel alloc] init];
label.tag                 = indexTag;
label.textColor           = self.badgeValueTextColor;
label.textAlignment       = NSTextAlignmentCenter;
label.font                = [UIFont systemFontOfSize:13.0f];
label.backgroundColor     = self.badgeValueBackgroundColor;
label.layer.masksToBounds = YES;
[button addSubview:label];
oldLabel                  = label;

}

oldLabel.hidden             = YES;
UITabBarItem *currentItem   = self.badgeValuesDic[key];
indexTag++;

if (!currentItem) continue;
if (currentItem.customBadgeValue == nil) continue;
if ([currentItem.customBadgeValue isEqualToString:@"0"]) return;
oldLabel.hidden             = NO;

NSString *title             = currentItem.customBadgeValue;

CGFloat itemWidth           = 0.0f;
CGFloat cornerRadius        = 0.0f;
NSInteger textLength        = title.length > 5 ? 5 : title.length;
itemWidth                   = 18.0f + (textLength-1) *8.0f;
cornerRadius                = 9.0f;

oldLabel.frame              = CGRectMake(buttonWidth *0.58f, 2.0f, itemWidth, 18.0f);
oldLabel.text               = title;
oldLabel.layer.cornerRadius = cornerRadius;

}

}

- (void)setItems:(NSArray<UITabBarItem *> *)items {

[super setItems:items];

NSInteger index       = 1000;

for (UITabBarItem *item in self.items ) {

item.index = index;

[self.badgeValuesDic setValue:item forKey:[NSString stringWithFormat:@"%ld",(long)item.index]];

index ++;
}

}

- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(badgeValueDidChange:) name:@"TabbarBadgeValueChange" object:nil];
self.badgeValueBackgroundColor = [UIColor redColor];
self.badgeValueTextColor       = [UIColor redColor];

}
return self;
}

#pragma mark - tabbar的 badgeValue 发生改变的通知

- (void)badgeValueDidChange:(NSNotification *)noti {

UITabBarItem *item       = (UITabBarItem *)noti.object;

if (!item || item.index == 0) return;

NSString *key            = [NSString stringWithFormat:@"%ld",(long)item.index];

self.badgeValuesDic[key] = item;

[self setNeedsLayout];

}

@end