-(UIViewController *)viewController{

UIResponder *nexRes=[self nextResponder];



do {

    //判读当前的响应者是否UIViewController

    if ([nexRes isKindOfClass:[UIViewController class]]) {

        //是否直接处理

        return  (UIViewController*)nexRes;

    }else{

        //否则继续寻找

        nexRes=[nexRes nextResponder];

        

    }

} while (nexRes!=nil);

return nil;

}