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如何让页面中有多个UIScrollView时支持statusbar点击回顶部的功能

在做PagerTab https://github.com/ming1016/PagerTab 这个滑动切换多页面的控件时发现如果有多个scroll view系统的点击statusbar滚动回顶部功能就会失效，查了些资料找到了解决的办法，现记录下。

主要思路是先创建一个UIWindow对象给它添加一个tap手势

static UIWindow *topWinow;  + (void)initialize {     topWinow = [[UIWindow alloc] init];     topWinow.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 20);     topWinow.windowLevel = UIWindowLevelAlert;     [topWinow addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(winTap)]]; }

递归搜索所有view查找当前位置合适的scroll view使其能够滚动到顶部

+ (void)seachScrollViewInView:(UIView *)view {  for (UIScrollView *subView in view.subviews) {   if ([subView isKindOfClass:[UIScrollView class]] && [self isCurrentShowView:subView]) {    //开始进行滚动    CGPoint offset = subView.contentOffset;    offset.y = -subView.contentInset.top;    [subView setContentOffset:offset animated:YES];   }   //寻找子视图的子视图   [self seachScrollViewInView:subView];  } } //根据位置判断是否合适 + (BOOL)isCurrentShowView:(UIView *)view {  UIWindow *keyWindow = [UIApplication sharedApplication].keyWindow;  CGRect currentFrame = [keyWindow convertRect:view.frame fromView:view.superview];  CGRect winBounds = keyWindow.bounds;  BOOL intersects = CGRectIntersectsRect(currentFrame, winBounds);  return !view.isHidden && view.alpha > 0.01 && view.window == keyWindow && intersects; }