UINavigationController相关

创建导航栏控制器，并添加到主窗口中

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];

    UINavigationController *navController = [[UINavigationController alloc]initWithRootViewController:[[ZFViewControllerFirst alloc]init]];

    self.window.rootViewController = navController;

    [self.window makeKeyAndVisible];

    return YES;
}

@end

当一个ViewController对象添加到导航栏控制器中，ViewController对象的navigationController就已经确定，在ViewController对象中就可以对navigationController进行操作

//跳转下一个ViewController，加载新的ViewController采用的是压栈的方式
[self.navigationController pushViewController:[[OtherViewController alloc]init] animated:YES];

//弹出当前ViewController返回上一个ViewController
[self.navigationController popViewControllerAnimated:YES];

//返回指定的某一级ViewController
[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];

//返回最初始的ViewController，根ViewController
[self.navigationController popToRootViewControllerAnimated:YES];

如要修改当前ViewController的navigationController的标题

[self.navigationItem setTitle:@"第三屏"];

修改当前ViewController的navigationController左右键

- (void)viewDidLoad {
    [super viewDidLoad];

    UIBarButtonItem *leftBarBtn = [[UIBarButtonItem alloc]initWithTitle:@"左导航键" style:UIBarButtonItemStylePlain target:self action:@selector(leftBtnClick)];
    [self.navigationItem setLeftBarButtonItem:leftBarBtn];

    UIBarButtonItem *rightBarBtn = [[UIBarButtonItem alloc]initWithTitle:@"右导航键" style:UIBarButtonItemStylePlain target:self action:@selector(rightBarClick)];
    [self.navigationItem setRightBarButtonItem:rightBarBtn];
}

- (void)leftBtnClick
{
    NSLog(@"%s",__func__);
}

- (void)rightBarClick
{
    NSLog(@"%s",__func__);
}

UIBarButtonItem的初始化方式

//以XIB的方式初始化
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;

//以图片的方式初始化
- (instancetype)initWithImage:(nullable UIImage *)image style:(UIBarButtonItemStyle)style target:(nullable id)target action:(nullable SEL)action;
- (instancetype)initWithImage:(nullable UIImage *)image landscapeImagePhone:(nullable UIImage *)landscapeImagePhone style:(UIBarButtonItemStyle)style target:(nullable id)target action:(nullable SEL)action NS_AVAILABLE_IOS(5_0); // landscapeImagePhone will be used for the bar button image when the bar has Compact or Condensed bar metrics.

//以标题文字的方式初始化
- (instancetype)initWithTitle:(nullable NSString *)title style:(UIBarButtonItemStyle)style target:(nullable id)target action:(nullable SEL)action;

//以BarButtonSystemItem系统控件进行初始化
- (instancetype)initWithBarButtonSystemItem:(UIBarButtonSystemItem)systemItem target:(nullable id)target action:(nullable SEL)action;

//以自定义View初始化
- (instancetype)initWithCustomView:(UIView *)customView;

隐藏导航条背景和阴影

直接设置导航条透明是无效的，但可以传一个空的图片作为导航条背景，这样看起来导航条就是空的，阴影同理

[self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc]init] forBarMetrics:UIBarMetricsDefault];

/*
     forBarMetrics:

     UIBarMetricsDefault,
     UIBarMetricsCompact,
     UIBarMetricsDefaultPrompt = 101, // Applicable only in bars with the prompt property, such as UINavigationBar and UISearchBar
     UIBarMetricsCompactPrompt,
*/

[self.navigationController.navigationBar setShadowImage:[[UIImage alloc]init]];

导航条背景和阴影透明度

为UIImage定义一个分类categray，功能为将颜色转为图片

#import "UIImage+Image.h"

@implementation UIImage (Image)

+ (UIImage *)imageWithColor:(UIColor *)color
{
    // 描述矩形
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);

    // 开启位图上下文
    UIGraphicsBeginImageContext(rect.size);
    // 获取位图上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    // 使用color演示填充上下文
    CGContextSetFillColorWithColor(context, [color CGColor]);
    // 渲染上下文
    CGContextFillRect(context, rect);
    // 从上下文中获取图片
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    // 结束上下文
    UIGraphicsEndImageContext();

    return theImage;
}

@end

用这个类可以将指定的颜色转换成图片

//设置一个透明度的颜色
UIColor *alphaColor = [UIColor colorWithWhite:1 alpha:0.5];

//转换颜色为图片
UIImage *alphaImage = [UIImage imageWithColor:alphaColor];
[self.navigationController.navigationBar

//将这个图片作为导航条的背景
setBackgroundImage:alphaImage forBarMetrics:UIBarMetricsDefault];

修改导航条标签文字的颜色

NSDictionary *attributes=[NSDictionary dictionaryWithObjectsAndKeys:[UIColor whiteColor],NSForegroundColorAttributeName,nil];
[self.navigationController.navigationBar setTitleTextAttributes:attributes];

//或者这样写
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSFontAttributeName] = [UIFont boldSystemFontOfSize:22];
dict[NSForegroundColorAttributeName] = [UIColor whiteColor];
[self.navigationController.navigationBar setTitleTextAttributes:dict];

使用NavigationBar Appearance整体修改导航条样式

获取全局导航条标识UINavigationBar appearance。appearance是个协议，只要遵守这个协议都会有这个方法

UINavigationBar *navigationBar = [UINavigationBar appearance];

[navigationBar setBackgroundImage:[UIImage imageNamed:@"NavBar64"] forBarMetrics:UIBarMetricsDefault];

NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSFontAttributeName] = [UIFont boldSystemFontOfSize:22];
dict[NSForegroundColorAttributeName] = [UIColor whiteColor];

[navigationBar setTitleTextAttributes:dict];

如果只希望个别几个控制器的导航条风格修改为统一样式

#import "ZFCustomNavigationController.h"
#import "ZFArenaViewController.h"

@interface ZFCustomNavigationController ()

@end

@implementation ZFCustomNavigationController

+ (void)initialize
{
    NSLog(@"%s",__func__);

    //设置为类方法所在类遵守appearance协议，
    //这样使用自定义的NavigationController为自定义风格
    //不使用该自定义NavigationController的为默认或其他风格
    NSArray *appearanceArr = @[[ZFCustomNavigationController class]];

    UINavigationBar *navigationBar = [UINavigationBar appearanceWhenContainedInInstancesOfClasses:appearanceArr];

    [navigationBar setBackgroundImage:[UIImage imageNamed:@"NavBar64"] forBarMetrics:UIBarMetricsDefault];

    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
    dict[NSFontAttributeName] = [UIFont boldSystemFontOfSize:22];
    dict[NSForegroundColorAttributeName] = [UIColor whiteColor];

    [navigationBar setTitleTextAttributes:dict];
}

统一修改返回按钮，比如非根以上控制器设置自定义的返回按钮，但要依然保持左滑动手势可以返回上一级控制器

//先实现UINavigationControllerDelegate代理
@interface ZFCustomNavigationController ()<UINavigationControllerDelegate>

@property(nonatomic,strong)id popGestureDelegate;

@end

@implementation ZFCustomNavigationController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    self.popGestureDelegate = self.interactivePopGestureRecognizer.delegate;

    self.delegate = self;
}

//如果只是一味的将手势代理清空，在根控制器使用手势依然有效，但是根控制器是不能被移除的，
//因此，在只剩根控制器还需要还原代理，这样就需要实现UINavigationControllerDelegate代理中的方法
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if(self.viewControllers[0] == viewController)
    {
        self.interactivePopGestureRecognizer.delegate = self.popGestureDelegate;
    }
    else
    {
        //想统一设置返回按钮，滑动移除控制器
        //清除手势代理就能实现滑动返回，iOS6不支持
        self.interactivePopGestureRecognizer.delegate = nil;
    }
}

//设置统一的返回按钮
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    [super pushViewController:viewController animated:animated];

    if(self.viewControllers.count > 1)
    {
        viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageWithNoRenderImageNamed:@"NavBack"] style:UIBarButtonItemStylePlain target:self action:@selector(back:)];
    }
}

@end

跳转到非根控制器隐藏tabbar

setting.hidesBottomBarWhenPushed = NO;