[self.tableView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionOld|NSKeyValueObservingOptionNew context:nil];

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary
     
       *)change context:(void *)context{    CGPoint oldPoint = [change[@"old"] CGPointValue];    CGPoint newPoint = [change[@"new"] CGPointValue];//    NSLog(@"%@",change);    CGFloat newY = newPoint.y;    CGFloat oldY = oldPoint.y;   if ( newY - oldY > 0) { //判断                self.imageView.y -= newY;                self.tableView.y = self.imageView.bottom;                [self.tableView setContentOffset:CGPointMake(0, 0)];         }    else if (  newY - oldY < 0) {//        self.imageView.y = self.imageView.y - newY;//        if (self.imageView.y >= 0) {//            self.imageView.y = 0;//        }//        self.tableView.y = self.imageView.bottom;        self.imageView.y -= newY;                self.tableView.y = self.imageView.bottom;                [self.tableView setContentOffset:CGPointMake(0, 0)];    }}