iOS超出父控件范围无法点击问题解决

#import "ViewController.h"
#import "BotView.h"
@interface ViewController ()
@property(strong, nonatomic) BotView *botView;
@property(strong, nonatomic) UIView *topView;
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    // Do any additional setup after loading the view.
    self.botView = [BotView new];
    self.topView = [UIView new];
    [self.view addSubview:self.botView];
    [self.botView addSubview:self.topView];
    self.botView.frame = CGRectMake(100, 100, 100, 100);
    self.topView.frame = CGRectMake(0, 0, 50, 200);
    self.botView.backgroundColor = [UIColor linkColor];
    self.topView.backgroundColor = [UIColor orangeColor];
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(topViewClick:)];
    [self.topView addGestureRecognizer:tap];
}
- (void)topViewClick:(UITapGestureRecognizer *)tap {
    NSLog(@"点击了顶部view");
}
@end

#import "BotView.h"
@implementation BotView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    int count = (int)self.subviews.count;
    for (int i=count-1; i>=0; i--) {
        UIView *subView = self.subviews[i];
        //点击事件作用在子控件上面，返回点击点
        CGPoint isPoint = [self convertPoint:point toView:subView];
        UIView *subv = [subView hitTest:isPoint withEvent:event];
        if (subv) {
            return subv;
        }
    }
    return self;
}
@end