• LZNavigationController

// LZNavigationController.h
#import <UIKit/UIKit.h>

@interface LZNavigationController : UINavigationController

@end


// LZNavigationController.m
#import "LZNavigationController.h"

@interface LZNavigationController () <UIGestureRecognizerDelegate>


@end

@implementation LZNavigationController

+ (void)initialize
{
    // 1.拿到導(dǎo)航條
    UINavigationBar *bar = [UINavigationBar appearanceWhenContainedIn:self, nil];

    // 2.目的把導(dǎo)航條背景圖片
    [bar setBackgroundImage:[UIImage imageNamed:@"navigationbarBackgroundWhite"] forBarMetrics:UIBarMetricsDefault];

    NSMutableDictionary * attr = [NSMutableDictionary dictionary];
    attr[NSFontAttributeName] = [UIFont boldSystemFontOfSize:20];
    // 3.設(shè)置字體大小
    [bar setTitleTextAttributes:attr];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    // Bug:假死狀態(tài):程序一直在跑,但是界面死了

    // 在根控制器下,滑動返回, 不應(yīng)該在跟控制器的view上滑動返回
    /*
    // 把代理給賦空值,那么滑動手勢就不會失效了耐齐，但是會有一個問題,當(dāng)你在根控制器還側(cè)滑的時候,
    // 這個時候這個手勢應(yīng)該是不應(yīng)該起作用的谤祖，誰告訴這個手勢不應(yīng)該起作用,代理，延柠，，可是代理已經(jīng)
    // 死了，就沒有人讓這個手勢不起作用,所以就會造成假死狀態(tài)
    self.interactivePopGestureRecognizer.delegate = nil;
     */

    self.interactivePopGestureRecognizer.delegate = self;
}

#pragma mark - UIGestureRecognizerDelegate方法
// 是否觸發(fā)手勢
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
    // 根控制器下不要觸發(fā)手勢,讓手勢不起作用
    return self.childViewControllers.count > 1 ;
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    // 滑動返回功能為什么失效:用滑動手勢做弃舒，驗證滑動手勢是否還在(驗證之后還在)
    // 代理可以控制手勢是否有效,驗證:代理做了一些事情,導(dǎo)致滑動手勢失效
    /**
     *  self.interactivePopGestureRecognizer =
        <UIScreenEdgePanGestureRecognizer: 0x7fa2d3c5c820; state = Possible; delaysTouchesBegan = YES; view = <UILayoutContainerView 0x7fa2d3ea5c60>; target= <(action=handleNavigationTransition:, target=<_UINavigationInteractiveTransition 0x7fa2d3c5c270>)>>

        self.interactivePopGestureRecognizer.delegate =
        <_UINavigationInteractiveTransition: 0x7fa7c372a850>    滑動手勢代理
     */

    if (self.childViewControllers.count != 0) { // 非根控制器

        viewController.navigationItem.leftBarButtonItem = [UIBarButtonItem itemWithTarget:self action:@selector(back) image:@"navigationButtonReturn" highImage:@"navigationButtonReturnClick" color:[UIColor blackColor] highColor:[UIColor redColor] title:@"返回"];

        self.hidesBottomBarWhenPushed = YES;
    }

    [super pushViewController:viewController animated:YES];
}

- (void)back
{
    [self popViewControllerAnimated:YES];
}

@end

• 主要步驟:
  • 遵守協(xié)議<UIGestureRecognizerDelegate>
  • 給控制器設(shè)置代理:self.interactivePopGestureRecognizer.delegate = self;
  • 實現(xiàn)代理方法

#pragma mark - UIGestureRecognizerDelegate方法
// 是否觸發(fā)手勢
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
    // 根控制器下不要觸發(fā)手勢,讓手勢不起作用
    return self.childViewControllers.count > 1 ;
}