其次，自定義左滑功能，利用系統提供的target和呼叫的方法，自己給導航控制器的view新增pan滑動手勢。記得要先禁用系統的左滑功能

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    NSLog(@"%@",self.interactivePopGestureRecognizer.delegate);
    //1、禁用系統自帶的滑動返回功能
    self.interactivePopGestureRecognizer.enabled = NO;
    
    //2、獲取系統左滑的target
    id target = self.interactivePopGestureRecognizer.delegate;
     UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:target action:@selector(handleNavigationTransition:)];
    panGestureRecognizer.delegate = self;
    [self.view addGestureRecognizer:panGestureRecognizer];
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    //判斷當前是不是導航控制器的第一層級控制器，如果是的話，返回手勢不觸發
    if (self.childViewControllers.count == 0) {
        return NO;
    }
    return YES;
}