声明一个按钮属性:

@property(nonatomic,strong)UIButton *valueBtn;
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在页面初始化地方创建按钮:

self.valueBtn = [[UIButton alloc]initWithFrame:CGRectMake(x, y, width, width)];
self.valueBtn.titleLabel.font = [UIFont systemFontOfSize:9];
self.valueBtn.titleLabel.textAlignment = NSTextAlignmentCenter;
self.valueBtn.userInteractionEnabled = NO;
self.valueBtn.backgroundColor = RGBCOLOR(234,36,36);
[self.valueBtn setTitleColor:RGBCOLOR(255, 254, 254) forState:UIControlStateNormal];
[self addSubview:self.valueBtn];
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自定义设置角标:

- (void)showBageValues:(NSInteger)bageValues{NSLog(@"-----showBageValues---%ld", bageValues);CGFloat width = 11;if (bageValues == 0) {self.valueBtn.hidden = YES;NSLog(@"-----valueBtn: %f---%f--%@", self.valueBtn.frame.size.height, self.valueBtn.frame.size.height, self.valueBtn);}else if (bageValues < 10){NSLog(@"---self.valueBtn.hidden = NO");self.valueBtn.hidden = NO;CGRect frame = self.valueBtn.frame;frame.size = CGSizeMake(width, width);self.valueBtn.frame = frame;self.valueBtn.layer.masksToBounds = YES;self.valueBtn.layer.cornerRadius = width/2;[self.valueBtn setTitle:[NSString stringWithFormat:@"%lu",bageValues] forState:UIControlStateNormal];}else if(bageValues < 100){self.valueBtn.hidden = NO;CGRect frame = self.valueBtn.frame;frame.size = CGSizeMake(width*1.6, width*1.1);self.valueBtn.frame = frame;self.valueBtn.layer.masksToBounds = YES;self.valueBtn.layer.cornerRadius = 6;[self.valueBtn setTitle:[NSString stringWithFormat:@"%lu",bageValues] forState:UIControlStateNormal];}else if (bageValues > 99){self.valueBtn.hidden = NO;CGRect frame = self.valueBtn.frame;frame.size = CGSizeMake(width*2.2, width*1.2);self.valueBtn.frame = frame;self.valueBtn.layer.masksToBounds = YES;self.valueBtn.layer.cornerRadius = 7;[self.valueBtn setTitle:[NSString stringWithFormat:@"99+"] forState:UIControlStateNormal];}
}
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问题描述: 登录A账号，假如获取消息角标数量为6，切换成B账号登录，假如B账户没有消息，则角标应该为0，即不显示角标，而此时角标却仍显示为6；

分析: 刚开始判断以为是退出登录时 没有清除相关数据，因为消息是集成的环信，所以就一直查看环信相关文档和Demo中相关代码，奇怪的是几乎没有类似的问题。 打断点调试，发现切换账号后，此时代码是走了如下代码的

if (bageValues == 0) {self.valueBtn.hidden = YES;NSLog(@"-----valueBtn: %f---%f--%@", self.valueBtn.frame.size.height, self.valueBtn.frame.size.height, self.valueBtn);}
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然后就想知道为什么明明设置了hidden为YES，却没有隐藏。

解决: 退出A账号 切换B账号或者不切换账号仍登录此账号，会先走初始化方法

self.valueBtn = [[UIButton alloc]initWithFrame:CGRectMake(x, y, width, width)];
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这样的写法会又创建一个按钮，而虽然走了self.valueBtn.hidden = YES;只是将新创建的按钮隐藏了，之前创建的那个valueBtn并没有隐藏，如果打印它们的地址，会发现两个不是同一个。因此，创建按钮修改为懒加载。