來自MG

//
//  MGNavVC.m
//  MGDemo
//
//  Created by ming on 16/7/8.
//  Copyright ? 2016年 ming. All rights reserved.
//

#import "MGNavVC.h"

@interface MGNavVC ()<UINavigationBarDelegate,UIGestureRecognizerDelegate>

@end

@implementation MGNavVC

+ (void)load {
    /// 1.UINavigationBar
    UINavigationBar *navBarAppearence = [UINavigationBar appearance];
    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
    dict[NSFontAttributeName] = [UIFont systemFontOfSize:17];
//    [navBarAppearence setBackgroundImage:[UIImage imageNamed:@"timo"] forBarMetrics:UIBarMetricsDefault];
    [navBarAppearence setTitleTextAttributes:dict];
}

#pragma mark ========= 添加全屏滑動手勢 ==========
- (void)viewDidLoad {
    [super viewDidLoad];
    
    // setp1:需要獲取系統(tǒng)自帶滑動手勢的target對象
    id target = self.interactivePopGestureRecognizer.delegate;
    
    // setp2:創(chuàng)建全屏滑動手勢~調(diào)用系統(tǒng)自帶滑動手勢的target的action方法
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:target action:@selector(handleNavigationTransition:)];
    
    // step3:設(shè)置手勢代理~攔截手勢觸發(fā)
    pan.delegate = self;
    
    // step4:別忘了~給導(dǎo)航控制器的view添加全屏滑動手勢
    [self.view addGestureRecognizer:pan];
    
    // step5:將系統(tǒng)自帶的滑動手勢禁用
    self.interactivePopGestureRecognizer.enabled = NO;
    
    // steo6:還記得剛剛設(shè)置的代理嗎？下面方法什么時候調(diào)用确沸？在每次觸發(fā)手勢之前都會詢問下代理捌锭，是否觸發(fā)。
}
- (void)handleNavigationTransition:(UIPanGestureRecognizer *)pan{
    NSLog(@"%s",__func__);
}
/** 判斷是否為根控制器 */
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
    // 只要不等于1就返回YES罗捎，說明此時具有滑動功能
    return self.childViewControllers.count != 1;
}

#pragma mark ========= 攔截控制器的push操作 ==========
/**
 *   攔截控制器的push操作
 */
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{
    
    if (self.childViewControllers.count > 0) {
        // 判斷當(dāng)前控制器是否為根控制器观谦，如果不是，就執(zhí)行下列代碼
        UIBarButtonItem *leftItem = [UIBarButtonItem itemWithImage:@"navigationButtonReturn"  highImage:nil title:@"返回" target:self action:@selector(leftBtnClick)];
    
        [viewController.navigationItem setLeftBarButtonItem:leftItem animated:YES];
        
        // 隱藏下面的TabBar
        viewController.hidesBottomBarWhenPushed = YES;
    }
//    else{
//        viewController.hidesBottomBarWhenPushed = NO;
//    }
    
    // 這句super的push要放在后面, 讓viewController可以覆蓋上面設(shè)置的leftBarButtonItem
    [super pushViewController:viewController animated:animated];
    
}

// 監(jiān)聽按鈕的點(diǎn)擊
- (void)leftBtnClick{
    [self popViewControllerAnimated:YES];
}

@end