第一步，建一个UITabBar的category类别
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第二步：上代码
#import <UIKit/UIKit.h>
@interface UITabBar (badge)
- (void)showBadgeOnItemIndex:(int)index; //显示小红点
- (void)hideBadgeOnItemIndex:(int)index; //隐藏小红点
@end
#import "UITabBar+badge.h"
#define TabbarItemNums 4.0 //tabbar的数量
@implementation UITabBar (badge)
- (void)showBadgeOnItemIndex:(int)index{
//移除之前的小红点
[self removeBadgeOnItemIndex:index];
//新建小红点
UIView *badgeView = [[UIView alloc]init];
badgeView.tag = 888 + index;
badgeView.layer.cornerRadius = 5;
badgeView.backgroundColor = [UIColor redColor];
CGRect tabFrame = self.frame;
//确定小红点的位置
float percentX = (index +0.6) / TabbarItemNums;
CGFloat x = ceilf(percentX * tabFrame.size.width);
CGFloat y = ceilf(0.1 * tabFrame.size.height);
badgeView.frame = CGRectMake(x, y, 10, 10);
[self addSubview:badgeView];
}
- (void)hideBadgeOnItemIndex:(int)index{
//移除小红点
[self removeBadgeOnItemIndex:index];
}
- (void)removeBadgeOnItemIndex:(int)index{
//按照tag值进行移除
for (UIView *subView in self.subviews) {
if (subView.tag == 888+index) {
[subView removeFromSuperview];
}
}
}
@end
第三步，在需要用到的地方使用
//显示
[self.tabBarController.tabBar showBadgeOnItemIndex:2];
//隐藏
[self.tabBarController.tabBar hideBadgeOnItemIndex:2]
