iOS，监听tableVIew的偏移量
1. 添加监听
[self.tableView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNewcontext:nil];
2.监听的处理
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if ([keyPath isEqualToString:@"contentOffset"])
{
CGPoint offset = [change[NSKeyValueChangeNewKey] CGPointValue];
}
}
3.移除监听
[self.tableView removeObserver:self forKeyPath:@"contentOffset" context:nil];
