我们写代码时经常会遇见需要提示消息数目的Button，去网上找的又不合心意，无奈之下只好自己写了一个类别来用，写的不好，想用的可以试试，不喜勿喷。
首先给UIButton写一个类别，定义一个对象方法:
- (void)setBadge:(NSString *)number andFont:(int)font;
实现如下：
- (void)setBadge:(NSString *)number andFont:(int)font{
CGFloat width = self.bounds.size.width;
CGSize size = [@"1" getSizeOfStringWihtFont:font addMaxSize:CGSizeMake(99, 99)];
UILabel *badge = [[UILabel alloc] initWithFrame:CGRectMake(width*2/3, -width/4, width/2+(number.length-1)*size.width, width/2)];
badge.text = number;
badge.textAlignment = NSTextAlignmentCenter;
badge.font = [UIFont systemFontOfSize:font];
badge.backgroundColor = [UIColor redColor];
badge.textColor = [UIColor whiteColor];
badge.layer.cornerRadius = width/4;
badge.layer.masksToBounds = YES;
[self addSubview:badge];
}
然后在外部引入头文件调用方法就可以了：
[btn setBadge:@"999" andFont:12];
/**获得字符串的大小*/
-(CGSize)getSizeOfStringWihtFont:(int)fontSize addMaxSize:(CGSize)maxSize
{
CGSize size=[self boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName: [UIFont systemFontOfSize:fontSize]} context:nil].size;
return size;
}
