iOS在自定义视图（常用于自定义cell）中获取导航控制器上面的当前的控制器对象

- (UIViewController *)viewController {
UIResponder *next = self.nextResponder;
do {
//判断响应者是否为视图控制器
if ([next isKindOfClass:[UIViewController class]]) {
return (UIViewController *)next;
}
next = next.nextResponder;
} while (next != nil);

return nil;
}