- (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NSMutableDictionaryNSMutableArray的方法 将HKPersonNSMutableDictionary来使用 */