UINavigationController全屏滑动返回

//注销系统方法
   self.interactivePopGestureRecognizer.enabled = NO;

// 创建全屏滑动手势，调用系统自带滑动手势的target的action方法
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self.interactivePopGestureRecognizer.delegate action:@selector(handleNavigationTransition:)];

// 设置手势代理，拦截手势触发 
// 声明UIGestureRecognizerDelegate 代理
    pan.delegate = self;

   // 给导航控制器的view添加全屏滑动手势
    [self.view addGestureRecognizer:pan];

// 什么时候调用：每次触发手势之前都会询问下代理，是否触发。
// 作用：拦截手势触发
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    // 注意：只有非根控制器才有滑动返回功能，根控制器没有。
    // 判断导航控制器是否只有一个子控制器，如果只有一个子控制器，肯定是根控制器
    if (self.childViewControllers.count == 1) {
        // 表示用户在根控制器界面，就不需要触发滑动手势，
        return NO;
    }
    return YES;
}

UINavigationController左边缘滑动返回

// 为了获取保存系统的 代理
@property (nonatomic ,assign) id target;

// 获取系统自带滑动手势的target对象
    self.target = self.interactivePopGestureRecognizer.delegate;
// 实现UINavigationControllerDelegate的代理和声明 
    self.delegate = self;

//UINavigationControllerDelegate 代理方法
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    
    if (viewController == [self.viewControllers firstObject] )
    {
        self.interactivePopGestureRecognizer.delegate = self.target;
    }
}

-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (self.childViewControllers.count>0)
    {
       // 设置导航条左边按钮的内容，把系统的返回按钮给覆盖，导航控制器的滑动返回功能就消失了 
       //覆盖后如果不把系统滑动返回功能注销 或自己重新实现 在首界面左边缘滑动会崩溃
     // 注销方法self.interactivePopGestureRecognizer.delegate = nil;
        UIButton *button = [[UIButton alloc] init];
        [button setImage:[UIImage imageNamed:@"返回"] forState:UIControlStateNormal];
        [button addTarget:self action:@selector(backButtonClick) forControlEvents:UIControlEventTouchUpInside];
        button.size = button.currentImage.size;
        viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];
        self.navigationBarHidden=NO;
        self.interactivePopGestureRecognizer.delegate = nil;
        viewController.automaticallyAdjustsScrollViewInsets=NO;
    }
    [super pushViewController:viewController animated:animated];
}
-(void)backButtonClick
{
    [self popViewControllerAnimated:YES];
}