ViewWithTag-查找子控件报错-优快云博客

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    // 求出标题按钮的索引
    NSUInteger index = scrollView.contentOffset.x / scrollView.width;
    // index == [0, 4]
    // 点击对应的标题按钮
    HKTitleButton *titleButton = self.titlesView.subviews[index];
    //HKTitleButton *titleButton = [self.titlesView viewWithTag:index];
    //此代码 索引为0时会报错(viewWithTag 递归查找，包括自己 先查找自己的tag，再查找子视图的tag，父视图默认tag为0，找到的是UIView而不是Button，所以setSelected方法找不到)
    [self titleButtonClick:titleButton];
}

此代码索引为0时会报错(viewWithTag 递归查找，包括自己先查找自己的tag，再查找子视图的tag，父视图默认tag为0，找到的是UIView而不是Button，所以setSelected方法找不到)

/*
 -[UIView setSelected:]: unrecognized selector sent to instance 0x7fbcba35ab10
 
 -[HKPerson length]: unrecognized selector sent to instance 0x7fbcba35ab10
 将HKPerson当做NSString来使用
 
 - (void)test:(NSString *)string
 {
 string.length;
 }
 id str = [[HKPerson alloc] init];
 [self test:str];
 
 -[HKPerson count]: unrecognized selector sent to instance 0x7fbcba35ab10
 将HKPerson当做NSArray或者NSDictionary来使用
 
 -[HKPerson setObject:forKeyedSubscript:]: unrecognized selector sent to instance 0x7fbcba35ab10
 名字中带有Subscript的方法，一般都是集合的方法，比如NSMutableDictionary\NSMutableArray的方法
 将HKPersonNSMutableDictionary来使用
 */

转载于:https://www.cnblogs.com/StevenHuSir/p/10114631.html