长按手势添加后总是调用两次的方法处理

最近在做项目的时候无论是简单的添加一个长按手势，还是在cell上添加长按手势，再触发方法后总是调用不止一次，处理方法如下：

- (void)btnLongPress:(UILongPressGestureRecognizer *)longPress
{
//    DLog(@"%@",longPress.view);
    UIButton *btn = (UIButton *)longPress.view;
    if ([longPress state] == UIGestureRecognizerStateBegan) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:[NSString stringWithFormat:@"是否将目前灯光设置存储在%@环境下?",btn.titleLabel.text] delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];
        alert.tag = longPress.view.tag;
        [alert show];
    }
}