OC語法中沒有直接移除子檢視的方法，但是可以通過查詢子檢視來移除

for(UIView *view in [self.view subviews])  
{  
   [view removefromsuperview]  
}  

來點直接的：實際上是用了NSArray的makeObjectsPerformSelector方法

[[self.view subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];  

或者

[self.view.subviews makeObjectsPerformSelector:@selector
 
(removeFromSuperview)];  
// 次方法由下面方法替代了  
[[self.view subviews] enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOLBOOL * _Nonnull stop) {  
        [(UIView*)obj removeFromSuperview];  
    }];