iPhone How-to：如何递归dump UIView

在学习和调试iPhone 界面或者某个控件的过程中，递归地dump出UIView是一个了解界面结构很有效的方法。这样不仅可以更好地发现问题，还可以定制某些系统的标准控件。要解决这类问题，很自然会想到递归函数。实现如下：

void dumpViews(UIView* view, NSString *label, NSString *indent)  { 
    Class klass = [view class]; 
    NSString *classDescription = getFullClassDescription(klass);    
    if ([label compare:@""] == NSOrderedSame) 
        NSLog(@"%@ %@", classDescription, NSStringFromCGRect(view.frame)); 
    else 
        NSLog(@"%@ %@ %@", label, classDescription, NSStringFromCGRect(view.frame)); 
    for (NSUInteger i = 0; i < [view.subviews count]; i++) 
    { 
        UIView *subView = [view.subviews objectAtIndex:i]; 
        NSString *newIndent = [[NSString alloc] initWithFormat:@"  %@", indent]; 
        NSString *newLabel = [[NSString alloc] initWithFormat:@"%@%d:", newIndent, i]; 
        dumpViews(subView, newLabel, newIndent); 
        [newLabel release]; 
        [newIndent release]; 
    } 
}

 

其中getFullClassDescription是用来获取某个类的继承关系描述：

NSString* getFullClassDescription(Class klass) { 
    NSString *description = [klass description]; 
    while ([klass superclass]) 
    { 
        klass = [klass superclass]; 
        description = [description stringByAppendingFormat:@":%@", [klass description]]; 
    } 
    return description; 
}

 

利用dumpViews对某应用的主窗体进行“偷窥”后输出结果如下：

UIWindow:UIView:UIResponder:NSObject {{0, 0}, {320, 480}} 
  0: UILayoutContainerView:UIView:UIResponder:NSObject {{0, 0}, {320, 480}} 
    0: UINavigationTransitionView:UIView:UIResponder:NSObject {{0, 0}, {320, 480}} 
    1: UINavigationBar:UIView:UIResponder:NSObject {{0, 0}, {320, 44}} 
       0: UINavigationItemView:UIView:UIResponder:NSObject {{160, 8}, {0, 27}}