点击状态栏回滚到顶部

一.新建一个类（继承NSObject）

.h文件声明方法

 
 
 
  
(void)show;
 
  
(void)hide;
 

.m文件实现方法

 static UIWindow *window_;
 
 
 
  
(void)initialize
 {
 window_ = [[UIWindow alloc] init];
 window_.frame = CGRectMake(0, 0, UIWidth, 20);
 window_.windowLevel = UIWindowLevelAlert;
 [window_ addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(windowClick)]];
 }
 
  
(void)show
 {
 window_.hidden = NO;
 }
 
  
(void)hide
 {
 window_.hidden = YES;
 
 
 
 
}
 
 
/**
 
 
 
  
监听窗口点击
 */
 
 
 
 
 
  
(void)windowClick
 {
 UIWindow *window = [UIApplication sharedApplication].keyWindow;
 [self searchScrollViewInView:window];
 
 
 
 
}
 
 
 
  
 
(void)searchScrollViewInView:(UIView *)superview
 {
 for (UIScrollView *subview in superview.subviews) {
 // 如果是scrollview, 滚动最顶部
 if ([subview isKindOfClass:[UIScrollView class]] && subview.isShowingOnKeyWindow) {
 CGPoint offset = subview.contentOffset;
 offset.y = - subview.contentInset.top;
 [subview setContentOffset:offset animated:YES];
 }
 
  // 继续查找子控件
  [self searchScrollViewInView:subview];
 
}
 }
 
 
 
 
 

注意：isShowOnKeyWindow方法请参参我的另一篇文章（判断View是否显示在屏幕上）http://www.jianshu.com/p/a9ab004e0619