获取当前View所在的ViewController

背景：AViewController 添加 BView，例如 [AViewController.view addSubview: bview]，在BView类中获取AViewController控制器，实现跳转等功能。

具体实现：

- (AViewController *)vc {    UIView* aView = [self superview];    AViewController * vc = nil;    UIResponder * responder = aView.nextResponder;    if ([responder isKindOfClass:[AViewController class]]) {        vc = (AViewController *)responder;    }    return vc;}