关于UITapGestureRecognizer的一些问题

1.一个gesture只能对应一个view。这是最根本的

//若这样写，那么只有self.view能添加手势，self.navigationController.navigationBar是添加不上的，因为被覆盖了
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideAddZone)];
gesture.numberOfTapsRequired = 1;
[self.navigationController.navigationBar addGestureRecognizer:gesture];
[self.view addGestureRecognizer:gesture];

//这样写也只能往self.view添加上手势，因为就算对gestureNavigation和gestureBaseview赋值，但它们都赋的为同一内存地址的gesture，
//本质上还是同一个gesture
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideAddZone)];
gesture.numberOfTapsRequired = 1;
self.gestureNavigation = gesture;
self.gestureBaseview = gesture;
[self.navigationController.navigationBar addGestureRecognizer:self.gestureNavigation];
[self.view addGestureRecognizer:self.gestureBaseview];

所以对不同的view,只能这样写

//可以这样写,这样两个view都可以加上手势
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideAddZone)];
gesture.numberOfTapsRequired = 1; //确认是单击其他区域，而不是双击等其它操作
[self.navigationController.navigationBar addGestureRecognizer:gesture];

UITapGestureRecognizer *gestureBaseView = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideAddZone)];
gestureBaseView.numberOfTapsRequired = 1;
[self.view addGestureRecognizer:gestureBaseView];

2.UITabBarController添加上手势后无法切换的问题

在viewDidLoad内对self.view添加手势

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UITapGestureRecognizer *gestureBaseView = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideAddZone)];
    gestureBaseView.numberOfTapsRequired = 1;
    self.gestureBaseview = gestureBaseView;
    [self.view addGestureRecognizer:self.gestureBaseview];
}

这样虽然可以添加手势，但底下的tabbar无法切换

此时需要做的就是实现手势的代理UIGestureRecognizerDelegate，需要手势时，返回YES;不需要时返回NO

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
    if (self.addView.hidden == YES) {
        return NO;
    } else {
        return YES;
    }
}