typedef NS_ENUM(NSInteger, UIBarMetrics) {UIBarMetricsDefault,//正常竖屏状态UIBarMetricsCompact,//横屏状态
};

- (void)viewDidLoad {[super viewDidLoad];UINavigationItem *item = [[UINavigationItem alloc]initWithTitle:@"Title1"];UINavigationBar *bar = [[UINavigationBar alloc]initWithFrame:CGRectMake(0, 0, 320, 64)];[[UINavigationBar appearance]setBarTintColor:[UIColor greenColor]];UIView *titleView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];titleView.backgroundColor = [UIColor redColor];item.titleView = titleView;item.prompt = @"标题的介绍";//隐藏返回按钮：hidesBackButton[bar pushNavigationItem:item animated:YES];[self.view addSubview:bar];self.view.backgroundColor = [UIColor grayColor];
}

@property(nullable, nonatomic,strong) UIBarButtonItem *leftBarButtonItem;
@property(nullable, nonatomic,strong) UIBarButtonItem *rightBarButtonItem;
- (void)setLeftBarButtonItem:(nullable UIBarButtonItem *)item animated:(BOOL)animated;
- (void)setRightBarButtonItem:(nullable UIBarButtonItem *)item animated:(BOOL)animated;
//添加多个按钮:
@property(nullable,nonatomic,copy) NSArray<UIBarButtonItem *> *leftBarButtonItems;
@property(nullable,nonatomic,copy) NSArray<UIBarButtonItem *> *rightBarButtonItems;
- (void)setLeftBarButtonItems:(nullable NSArray<UIBarButtonItem *> *)items animated:(BOOL)animated;
- (void)setRightBarButtonItems:(nullable NSArray<UIBarButtonItem *> *)items animated:(BOOL)animated;

typedef NS_ENUM(NSInteger, UIBarButtonItemStyle) {UIBarButtonItemStylePlain,UIBarButtonItemStyleDone,
};

- (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;//landscapeImagePhone style这个参数可以设置设备横屏时的图片//自定义View:
- (instancetype)initWithCustomView:(UIView *)customView;//原生的BarButtonItem:
UIBarButtonItem * button = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCamera target:self action:nil];typedef NS_ENUM(NSInteger, UIBarButtonSystemItem) {UIBarButtonSystemItemDone,//显示完成UIBarButtonSystemItemCancel,//显示取消UIBarButtonSystemItemEdit,  //显示编辑UIBarButtonSystemItemSave, //显示保存 UIBarButtonSystemItemAdd,//显示加号UIBarButtonSystemItemFlexibleSpace,//什么都不显示，占位一个空间位置UIBarButtonSystemItemFixedSpace,//和上一个类似UIBarButtonSystemItemCompose,//显示写入按钮UIBarButtonSystemItemReply,//显示循环按钮UIBarButtonSystemItemAction,//显示活动按钮UIBarButtonSystemItemOrganize,//显示组合按钮UIBarButtonSystemItemBookmarks,//显示图书按钮UIBarButtonSystemItemSearch,//显示查找按钮UIBarButtonSystemItemRefresh,//显示刷新按钮UIBarButtonSystemItemStop,//显示停止按钮UIBarButtonSystemItemCamera,//显示相机按钮UIBarButtonSystemItemTrash,//显示移除按钮UIBarButtonSystemItemPlay,//显示播放按钮UIBarButtonSystemItemPause,//显示暂停按钮UIBarButtonSystemItemRewind,//显示退后按钮UIBarButtonSystemItemFastForward,//显示前进按钮UIBarButtonSystemItemUndo,//显示消除按钮UIBarButtonSystemItemRedo ,//显示重做按钮UIBarButtonSystemItemPageCurl ,//在tool上有效
};

//向栈中添加一个item，上一个item会被推向导航栏的左侧，变为pop按钮，会有一个动画效果
- (void)pushNavigationItem:(UINavigationItem *)item animated:(BOOL)animated;
//pop一个item
- (nullable UINavigationItem *)popNavigationItemAnimated:(BOOL)animated;
//当前push到最上层的item
@property(nullable, nonatomic,readonly,strong) UINavigationItem *topItem;
//仅次于最上层的item，一般式被推向导航栏左侧的item
@property(nullable, nonatomic,readonly,strong) UINavigationItem *backItem;
//获取堆栈中所有item的数组
@property(nullable,nonatomic,copy) NSArray<UINavigationItem *> *items;
//设置一组item
- (void)setItems:(nullable NSArray<UINavigationItem *> *)items animated:(BOOL)animated;

@property(nullable,nonatomic,weak) id<UINavigationBarDelegate> delegate;

//item将要push的时候调用，返回NO，则不能push
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPushItem:(UINavigationItem *)item;
//item已经push后调用
- (void)navigationBar:(UINavigationBar *)navigationBar didPushItem:(UINavigationItem *)item;
//item将要pop时调用，返回NO，不能pop
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item;
//item已经pop后调用
- (void)navigationBar:(UINavigationBar *)navigationBar didPopItem:(UINavigationItem *)item;

//工具栏的风格，和导航栏类似，有黑白两种
@property(nonatomic) UIBarStyle barStyle;
//设置工具栏上按钮数组
@property(nullable,nonatomic,copy) NSArray<UIBarButtonItem *> *items;
//设置工具栏是否透明
@property(nonatomic,assign,getter=isTranslucent) BOOL translucent;
//设置工具栏按钮
- (void)setItems:(nullable NSArray<UIBarButtonItem *> *)items animated:(BOOL)animated;
//设置item风格颜色
@property(null_resettable, nonatomic,strong) UIColor *tintColor;
//设置工具栏背景色
@property(nullable, nonatomic,strong) UIColor *barTintColor;
//设置工具栏背景和阴影图案
- (void)setBackgroundImage:(nullable UIImage *)backgroundImage forToolbarPosition:(UIBarPosition)topOrBottom barMetrics:(UIBarMetrics)barMetrics;
- (nullable UIImage *)backgroundImageForToolbarPosition:(UIBarPosition)topOrBottom barMetrics:(UIBarMetrics)barMetrics;
- (void)setShadowImage:(nullable UIImage *)shadowImage forToolbarPosition:(UIBarPosition)topOrBottom;
- (nullable UIImage *)shadowImageForToolbarPosition:(UIBarPosition)topOrBottom;