监听UINavigationController 滑动返回手势

1、添加代理 UINavigationControllerDelegate

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [self.navigationController.navigationBar setHidden:YES];
    if ([[[UIDevice currentDevice] systemVersion] floatValue] > 7.0) {
        self.navigationController.delegate = self;
    }
}

- (void)viewWillDisappear:(BOOL)animated{
    if ([[[UIDevice currentDevice] systemVersion] floatValue] > 7.0) {
        self.navigationController.delegate = nil;
    }
}

2、实现代理方法

//监听滑动手势
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated{
    id <UIViewControllerTransitionCoordinator>tc = navigationController.topViewController.transitionCoordinator;
    [tc notifyWhenInteractionChangesUsingBlock:^(id<UIViewControllerTransitionCoordinatorContext>  _Nonnull context) {
        [dataKit kit].reloadFlage = [context isCancelled];
    }];
}

[context isCancelled] 是BOOL类型，未返回[context isCancelled]==YES，返回成功[context isCancelled]==NO。

点击按钮返回 或使用 [navigationController popviewcontorller] 不进入此回调。