写一个类别加上就可以啦
#import "UIBarButtonItem+Badge.h"
#import "BadgeView.h"
#import <PureLayout/PureLayout.h>
@implementation UIBarButtonItem (Badge)
-(void)addBadgeWithNum:(NSNumber *)num{
for (UIView *view in self.customView.subviews) {
if ([view isKindOfClass:[BadgeView class]]) {
[view removeFromSuperview];
}
}
if (num>0) {
BadgeView *badgeView = [[BadgeView alloc]initWithNumber:num];
[self.customView addSubview:badgeView];
[badgeView autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:8];
[badgeView autoPinEdgeToSuperviewEdge:ALEdgeTop withInset:3];
}
}