什么是删除UIScrollView的所有子视图的好方法？

Question

我有一个滚动视图，我需要经常在我的应用程序运行时重新加载内容。现在，我使用下面的代码行再次加入他们之前删除子视图：

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

我应该使用，而不是下面的？

scrollView.subviews = nil; 

出于某种原因，第一行代码似乎每运行16次就会使应用程序崩溃。我是否在某处泄漏了记忆？下面的方法需要一个视图数组，滚动条（这是一个常量）和方向。

编辑：

- (void)loadViews:(NSArray *)views IntoScroller:(UIScrollView *)scroller withDirection:(NSString *)direction{ 
//Set up the scrollView 

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

if([direction isEqualToString:@"horizontal"]){ 
    scrollView.frame = CGRectMake(0, 0, 1024, 768); 
    scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * [[NSNumber numberWithUnsignedInt:[views count]] floatValue], scrollView.frame.size.height); 
}else if([direction isEqualToString:@"vertical"]){ 
    scrollView.frame = CGRectMake(0, 0, 1024, 768); 
    scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, scrollView.frame.size.height * [[NSNumber numberWithUnsignedInt:[views count]] floatValue]); 
} 

for (int i=0; i<[[NSNumber numberWithUnsignedInt:[views count]] intValue]; i++) { 

    [[[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view] setFrame:scrollView.frame]; 

    if([direction isEqualToString:@"horizontal"]){ 
     [[[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view] setFrame:CGRectMake(i * [[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view].frame.size.width, 0, scrollView.frame.size.width, scrollView.frame.size.height)];//CGRectMake(i * announcementView.view.frame.size.width, -scrollView.frame.origin.x, scrollView.frame.size.width, scrollView.frame.size.height)]; 
    }else if([direction isEqualToString:@"vertical"]){ 
     [[[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view] setFrame:CGRectMake(0, i * [[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view].frame.size.height, scrollView.frame.size.width, scrollView.frame.size.height)]; 
    } 

    [scrollView addSubview:[[views objectAtIndex:[[NSNumber numberWithInt:i] unsignedIntValue]] view]]; 
} 

}

Answer 1

，你给是从UIScrollView删除子视图的正确方法的第一个例子。

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

设置subviews到nil有效尼尔斯时的集合对象管理的子视图，从而不可能增加新的子视图。

Answer 2

下面是删除从滚动视图的所有子视图代码：

for(UIView *subview in [scrollview subviews]) 
     { 
     [subview removeFromSuperview]; 

     }