一、導(dǎo)航控制器和工具欄

在 iOS 開發(fā)中，UINavigationController?是一個視圖控制器管理器，用于在多個視圖控制器之間進行有層級的導(dǎo)航（如頁面的前進、返回），就像網(wǎng)頁的前進/后退一樣。

繼承關(guān)系：NSObject->UIResponder->UIViewController->UINavigationController

#import <UIKit/UIKit.h>NS_ASSUME_NONNULL_BEGIN@interface VCRoot : UIViewController@endNS_ASSUME_NONNULL_END

#import "VCRoot.h"@interface VCRoot ()@end@implementation VCRoot- (void)viewDidLoad {[super viewDidLoad];[super viewDidLoad];self.view.backgroundColor = [UIColor blackColor];self.navigationItem.title = @"Pornhub";UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];[appearance configureWithOpaqueBackground];appearance.backgroundColor = [UIColor orangeColor];
appearance.titleTextAttributes = @{ NSForegroundColorAttributeName : [UIColor whiteColor] };self.navigationController.navigationBar.standardAppearance = appearance;self.navigationController.navigationBar.scrollEdgeAppearance = appearance;//創(chuàng)建一個導(dǎo)航欄左側(cè)的按鈕，這是根據(jù)title文字來創(chuàng)建的，傳入四個參數(shù)//第一個參數(shù)是按鈕上的文字內(nèi)容；第二個參數(shù)是按鈕風格//第三個參數(shù)是事件的擁有者；第四個參數(shù)是按鈕的事件函數(shù)UIBarButtonItem *leftBtn = [[UIBarButtonItem alloc] initWithTitle: @"<" style: UIBarButtonItemStyleDone target: self action: @selector(pressLeft)];//給導(dǎo)航欄的左側(cè)按鈕屬性賦值為我們創(chuàng)建好的左側(cè)按鈕self.navigationItem.leftBarButtonItem = leftBtn;//右側(cè)按鈕//和左側(cè)按鈕不同的是，這里創(chuàng)建右側(cè)按鈕的時候我們使用的初始化方法是不一樣的//這里的初始化方法不需要輸入文字內(nèi)容，而是指定了系統(tǒng)提供的風格樣式，系統(tǒng)風格的按鈕內(nèi)容或標題文字不可更改UIBarButtonItem *rightBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemAdd target: self action: @selector(pressRight)];self.navigationItem.rightBarButtonItem = rightBtn;//創(chuàng)建多按鈕：//先創(chuàng)建一個標簽對象UILabel *label = [[UILabel alloc] initWithFrame: CGRectMake(10, 10, 50, 40)];label.text = @"???🔥🔞";//將label設(shè)置為居中l(wèi)abel.textAlignment = NSTextAlignmentCenter;label.textColor = [UIColor orangeColor];//將UIlabel類型的控件添加到導(dǎo)航欄按鈕//initWithCustomView就代表以自定義控件來初始化UIBarButtonItem *item3 = [[UIBarButtonItem alloc] initWithCustomView: label];//創(chuàng)建一個按鈕數(shù)組NSArray *arrayBtn = [NSArray arrayWithObjects: rightBtn, item3, nil];//將右側(cè)按鈕數(shù)組賦值self.navigationItem.rightBarButtonItems = arrayBtn;}- (void) pressLeft {NSLog(@"左側(cè)按鈕被按下");
}- (void) pressRight {NSLog(@"右側(cè)按鈕被按下");
}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "SceneDelegate.h"
#import "VCRoot.h"
@interface SceneDelegate ()@end@implementation SceneDelegate- (void)scene:(UIScene *)scene
willConnectToSession:(UISceneSession *)sessionoptions:(UISceneConnectionOptions *)connectionOptions
{// 初始化 window 并綁定到當前 sceneself.window = [[UIWindow alloc] initWithWindowScene:(UIWindowScene *)scene];self.window.frame = [UIScreen mainScreen].bounds;// 創(chuàng)建根視圖控制器VCRoot* root = [[VCRoot alloc] init];// 創(chuàng)建導(dǎo)航控制器并設(shè)置根視圖控制器UINavigationController* nav = [[UINavigationController alloc] initWithRootViewController:root];// 設(shè)置 window 的根控制器self.window.rootViewController = nav;// 顯示窗口[self.window makeKeyAndVisible];
}- (void)sceneDidDisconnect:(UIScene *)scene {// Called as the scene is being released by the system.// This occurs shortly after the scene enters the background, or when its session is discarded.// Release any resources associated with this scene that can be re-created the next time the scene connects.// The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
}- (void)sceneDidBecomeActive:(UIScene *)scene {// Called when the scene has moved from an inactive state to an active state.// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}- (void)sceneWillResignActive:(UIScene *)scene {// Called when the scene will move from an active state to an inactive state.// This may occur due to temporary interruptions (ex. an incoming phone call).
}- (void)sceneWillEnterForeground:(UIScene *)scene {// Called as the scene transitions from the background to the foreground.// Use this method to undo the changes made on entering the background.
}- (void)sceneDidEnterBackground:(UIScene *)scene {// Called as the scene transitions from the foreground to the background.// Use this method to save data, release shared resources, and store enough scene-specific state information// to restore the scene back to its current state.
}@end

導(dǎo)航控制器切換

#import "VCRoot.h"
#import "VCSecond.h"
@interface VCRoot ()@end@implementation VCRoot- (void)viewDidLoad {[super viewDidLoad];[super viewDidLoad];self.view.backgroundColor = [UIColor blackColor];self.navigationItem.title = @"Pornhub";UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];[appearance configureWithOpaqueBackground];appearance.backgroundColor = [UIColor orangeColor];
appearance.titleTextAttributes = @{ NSForegroundColorAttributeName : [UIColor whiteColor] };self.navigationController.navigationBar.standardAppearance = appearance;self.navigationController.navigationBar.scrollEdgeAppearance = appearance;//創(chuàng)建一個導(dǎo)航欄左側(cè)的按鈕，這是根據(jù)title文字來創(chuàng)建的，傳入四個參數(shù)//第一個參數(shù)是按鈕上的文字內(nèi)容；第二個參數(shù)是按鈕風格//第三個參數(shù)是事件的擁有者；第四個參數(shù)是按鈕的事件函數(shù)UIBarButtonItem *leftBtn = [[UIBarButtonItem alloc] initWithTitle: @"<" style: UIBarButtonItemStyleDone target: self action: @selector(pressLeft)];//給導(dǎo)航欄的左側(cè)按鈕屬性賦值為我們創(chuàng)建好的左側(cè)按鈕self.navigationItem.leftBarButtonItem = leftBtn;//右側(cè)按鈕//和左側(cè)按鈕不同的是，這里創(chuàng)建右側(cè)按鈕的時候我們使用的初始化方法是不一樣的//這里的初始化方法不需要輸入文字內(nèi)容，而是指定了系統(tǒng)提供的風格樣式，系統(tǒng)風格的按鈕內(nèi)容或標題文字不可更改
//    UIBarButtonItem *rightBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemAdd target: self action: @selector(pressRight)];
//    self.navigationItem.rightBarButtonItem = rightBtn;UIBarButtonItem *next = [[UIBarButtonItem alloc] initWithTitle: @">>" style: UIBarButtonItemStylePlain target: self action: @selector(pressNext)];self.navigationItem.rightBarButtonItem = next;//創(chuàng)建多按鈕：//先創(chuàng)建一個標簽對象UILabel *label = [[UILabel alloc] initWithFrame: CGRectMake(10, 10, 50, 40)];label.text = @"???🔥🔞";//將label設(shè)置為居中l(wèi)abel.textAlignment = NSTextAlignmentCenter;label.textColor = [UIColor orangeColor];//將UIlabel類型的控件添加到導(dǎo)航欄按鈕//initWithCustomView就代表以自定義控件來初始化UIBarButtonItem *item3 = [[UIBarButtonItem alloc] initWithCustomView: label];//創(chuàng)建一個按鈕數(shù)組// NSArray *arrayBtn = [NSArray arrayWithObjects: rightBtn, item3, nil];//將右側(cè)按鈕數(shù)組賦值
//    self.navigationItem.description = label;}- (void) pressLeft {NSLog(@"左側(cè)按鈕被按下");
}- (void)pressNext {//創(chuàng)建新的視圖控制器VCSecond *vcSecond = [[VCSecond alloc] init];//使用當前視圖控制器的導(dǎo)航控制器對象[self.navigationController pushViewController: vcSecond animated: YES];
}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "VCSecond.h"
#import "VCThird.h"@interface VCSecond ()@end@implementation VCSecond- (void)viewDidLoad {[super viewDidLoad];//設(shè)置視圖二的標題和顏色self.view.backgroundColor = [UIColor whiteColor];self.title = @"歐美";//為視圖控制器導(dǎo)航欄設(shè)置右側(cè)按鈕UIBarButtonItem *btnNext = [[UIBarButtonItem alloc] initWithTitle: @"下一級" style: UIBarButtonItemStylePlain target: self action: @selector(pressNext)];self.navigationItem.rightBarButtonItem = btnNext;//為視圖控制器導(dǎo)航欄設(shè)置返回的左側(cè)按鈕UIBarButtonItem *btnLeft = [[UIBarButtonItem alloc] initWithTitle: @"返回上一級" style: UIBarButtonItemStylePlain target: self action: @selector(pressBack)];self.navigationItem.leftBarButtonItem = btnLeft;
}- (void)pressNext {//創(chuàng)建新的視圖控制器VCThird *vcThird = [[VCThird alloc] init];//推入第三個視圖控制器對象[self.navigationController pushViewController: vcThird animated: YES];}- (void)pressBack {//將當前視圖控制器彈出，返回到上一級界面[self.navigationController popViewControllerAnimated: YES];
}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "VCThird.h"@interface VCThird ()@end@implementation VCThird- (void)viewDidLoad {[super viewDidLoad];self.view.backgroundColor = [UIColor colorWithRed: 0.7 green: 0.2 blue: 0.5 alpha: 1];self.title = @"亞非";UIBarButtonItem *btnLeft = [[UIBarButtonItem alloc] initWithTitle: @"返回上一級" style: UIBarButtonItemStylePlain target: self action: @selector(pressBack)];self.navigationItem.leftBarButtonItem = btnLeft;UIBarButtonItem *btnRight = [[UIBarButtonItem alloc] initWithTitle: @"返回根視圖" style: UIBarButtonItemStylePlain target: self action: @selector(pressRoot)];self.navigationItem.rightBarButtonItem = btnRight;
}- (void)pressBack {//將當前視圖控制器彈出,返回到上一級界面[self.navigationController popViewControllerAnimated: YES];
}- (void)pressRoot {//將當前視圖彈出，并返回根視圖[self.navigationController popToRootViewControllerAnimated: YES];
}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "SceneDelegate.h"
#import "VCRoot.h"@interface SceneDelegate ()@end@implementation SceneDelegate- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {self.window.frame = [UIScreen mainScreen].bounds;//在這里創(chuàng)建了一個根視圖控制器，直接將這個根視圖控制器賦值給了導(dǎo)航控制器的根視圖對象，然后這個導(dǎo)航控制器又作為了window的根視圖控制器self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController: [[VCRoot alloc] init]];[self.window makeKeyAndVisible];
}- (void)sceneDidDisconnect:(UIScene *)scene {// Called as the scene is being released by the system.// This occurs shortly after the scene enters the background, or when its session is discarded.// Release any resources associated with this scene that can be re-created the next time the scene connects.// The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
}- (void)sceneDidBecomeActive:(UIScene *)scene {// Called when the scene has moved from an inactive state to an active state.// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}- (void)sceneWillResignActive:(UIScene *)scene {// Called when the scene will move from an active state to an inactive state.// This may occur due to temporary interruptions (ex. an incoming phone call).
}- (void)sceneWillEnterForeground:(UIScene *)scene {// Called as the scene transitions from the background to the foreground.// Use this method to undo the changes made on entering the background.
}- (void)sceneDidEnterBackground:(UIScene *)scene {// Called as the scene transitions from the foreground to the background.// Use this method to save data, release shared resources, and store enough scene-specific state information// to restore the scene back to its current state.
}@end

導(dǎo)航欄和工具欄

分欄控制器

? ?有以下幾個屬性：

UITabBarltem：分欄按鈕元素對象

badgeValue：分欄按鈕提示信息

selectedIndex：分欄控制器選中的控制索引

viewControllers：分欄控制器管理數(shù)組

selectedViewController：分欄控制器選中的控制器對象

? ? ? ? 要注意的是，在SceneDelegate中改了按鈕的標題內(nèi)容，然后又在創(chuàng)建的視圖控制器對象的.m文件中更改標題時，應(yīng)該在SceneDelegate中把會用到視圖控制器對象的.m中的viewDidLoad函數(shù)的語句放在在SceneDelegate的標題賦值語句的后面，因為如果不放在后面就會導(dǎo)致標題被覆蓋，無法更改為創(chuàng)建的視圖控制器對象的標題內(nèi)容

代碼演示：

首先需要創(chuàng)建三個視圖控制器：FirstVC、SecondVC、ThirdVC：

#import "FirstVC.h"@interface FirstVC ()@end@implementation FirstVC- (void)viewDidLoad {[super viewDidLoad];UITabBarItem* tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemSearchtag:101];self.tabBarItem = tabBarItem;// Do any additional setup after loading the view.
}/*
#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "SecondVC.h"@interface SecondVC ()@end@implementation SecondVC- (void)viewDidLoad {[super viewDidLoad];//根據(jù)系統(tǒng)風格設(shè)置分欄控制器按鈕，傳入兩個參數(shù)//第一個參數(shù)指分欄控制器的按鈕風格，第二個參數(shù)是分欄控件對象的標簽值UITabBarItem *tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem: UITabBarSystemItemContacts tag: 103];//為分欄按鈕設(shè)置提示的標記值信息，是系統(tǒng)的，無法變更tabBarItem.badgeValue = @"99";self.tabBarItem = tabBarItem;}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "ThirdVC.h"@interface ThirdVC ()@end@implementation ThirdVC- (void)viewDidLoad {[super viewDidLoad];UITabBarItem *tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavoritestag: 103];//為分欄按鈕設(shè)置提示的標記值信息，是系統(tǒng)的，無法變更tabBarItem.badgeValue = @"99";self.tabBarItem = tabBarItem;// Do any additional setup after loading the view.
}/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import "SceneDelegate.h"
#import "FirstVC.h"
#import "SecondVC.h"
#import "ThirdVC.h"@interface SceneDelegate ()@end@implementation SceneDelegate- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {//創(chuàng)建三個視圖控制器并更改背景顏色和標題FirstVC *vc1 = [[FirstVC alloc] init];vc1.title = @"視圖1";SecondVC *vc2 = [[SecondVC alloc] init];vc2.title = @"視圖2";ThirdVC *vc3 = [[ThirdVC alloc] init];vc3.title = @"視圖3";vc1.view.backgroundColor = [UIColor brownColor];vc2.view.backgroundColor = [UIColor orangeColor];vc3.view.backgroundColor = [UIColor yellowColor];//創(chuàng)建分欄控制器對象UITabBarController *tbc = [[UITabBarController alloc] init];//創(chuàng)建一個控制器數(shù)組對象，并將所有要被分欄控制器管理的對象添加進數(shù)組//分欄控制器的按鈕的位置就取決于在數(shù)組中存放的位置NSArray *arrVC = [NSArray arrayWithObjects: vc1, vc2, vc3, nil];//將分欄控制器管理數(shù)組賦值tbc.viewControllers = arrVC;//將分欄控制器做為根視圖控制器self.window.rootViewController = tbc;//設(shè)置選中的視圖控制器的索引//通過索引來確定一打開程序的時候是顯示的哪一個視圖控制器，并且此時分欄控制器選中的控制器對象就是索引為2的視圖控制器tbc.selectedIndex = 2;//分欄控制器選中的控制器對象if (tbc.selectedViewController == vc3) {NSLog(@"分欄控制器選中的控制器對象是索引為2的視圖控制器");}//設(shè)置分欄控制器的工具欄的透明度tbc.tabBar.translucent = NO;//設(shè)置分欄控制器工具欄的背景顏色tbc.tabBar.backgroundColor = [UIColor whiteColor];//設(shè)置分欄控制器工具欄的按鈕選擇時顏色tbc.tabBar.tintColor = [UIColor redColor];}- (void)sceneDidDisconnect:(UIScene *)scene {// Called as the scene is being released by the system.// This occurs shortly after the scene enters the background, or when its session is discarded.// Release any resources associated with this scene that can be re-created the next time the scene connects.// The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
}- (void)sceneDidBecomeActive:(UIScene *)scene {// Called when the scene has moved from an inactive state to an active state.// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}- (void)sceneWillResignActive:(UIScene *)scene {// Called when the scene will move from an active state to an inactive state.// This may occur due to temporary interruptions (ex. an incoming phone call).
}- (void)sceneWillEnterForeground:(UIScene *)scene {// Called as the scene transitions from the background to the foreground.// Use this method to undo the changes made on entering the background.
}- (void)sceneDidEnterBackground:(UIScene *)scene {// Called as the scene transitions from the foreground to the background.// Use this method to save data, release shared resources, and store enough scene-specific state information// to restore the scene back to its current state.
}@end

分欄控制器高級

一些方法：

willBeginCustomizingViewControllers:即將顯示編輯方法

willEndCustomizingViewControllers:即將結(jié)束編輯方法

didEndCustomizingViewControllers:已經(jīng)結(jié)束編輯方法

didSelectViewController:選中控制器切換方法

在給分欄控件添加按鈕的時候，為了用戶體驗，下面頁面最多顯示五個按鈕，當添加的按鈕多于五個的時候，系統(tǒng)就會自動把最后一個按鈕替換成“more”，然后點開more，才能看見被折疊的其他按鈕。然后在點開more后的頁面中的右上角會有一個edit按鈕，這個按鈕點開后，會出現(xiàn)我們創(chuàng)建的全部視圖，拖動上面的任意視圖到下面的分欄視圖中，可以交換被折疊和被顯示的那兩個視圖

UITabBarControllerDelegate協(xié)議

為了實現(xiàn)UITabBarControllerDelegate協(xié)議，要在SceneDelegate.h中先引用該協(xié)議

代碼演示：

在此之前需要創(chuàng)建六個視圖控制器：FirstViewController、SecondViewController、ThirdViewController、ForthViewController、FifthViewController、sixthViewController

然后在在SceneDelegate.m中：

#import "SceneDelegate.h"
#import "FirstViewController.h"
#import "SecondViewController.h"
#import "ThirdViewController.h"
#import "ForthViewController.h"
#import "FifthViewController.h"
#import "SixthViewController.h"@interface SceneDelegate ()@end@implementation SceneDelegate- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {FirstViewController *vc1 = [[FirstViewController alloc] init];SecondViewController *vc2 = [[SecondViewController alloc] init];ThirdViewController *vc3 = [[ThirdViewController alloc] init];ForthViewController *vc4 = [[ForthViewController alloc] init];FifthViewController *vc5 = [[FifthViewController alloc] init];sixthViewController *vc6 = [[sixthViewController alloc] init];vc1.title = @"視圖1";vc2.title = @"視圖2";vc3.title = @"視圖3";vc4.title = @"視圖4";vc5.title = @"視圖5";vc6.title = @"視圖6";vc1.view.backgroundColor = [UIColor redColor];vc2.view.backgroundColor = [UIColor orangeColor];vc3.view.backgroundColor = [UIColor yellowColor];vc4.view.backgroundColor = [UIColor greenColor];vc5.view.backgroundColor = [UIColor blueColor];vc6.view.backgroundColor = [UIColor purpleColor];NSArray *arrVC = [NSArray arrayWithObjects: vc1, vc2, vc3, vc4, vc5, vc6, nil];UITabBarController *btc = [[UITabBarController alloc] init];btc.viewControllers = arrVC;self.window.rootViewController = btc;//處理UITabBarControllerDelegate協(xié)議函數(shù)//設(shè)置代理btc.delegate = self;
}//以下是協(xié)議中函數(shù)的用法，其中“編輯”是指在分欄控制器中的more中通過拖動更改和交換顯示和折疊的視圖控制器的操作------------------------------------------------------------
//即將開始編輯前會調(diào)用此協(xié)議函數(shù)
- (void)tabBarController:(UITabBarController *)tabBarController willBeginCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers {NSLog(@"編輯前");
}//即將結(jié)束前調(diào)用該協(xié)議函數(shù)
- (void)tabBarController:(UITabBarController *)tabBarController willEndCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers changed:(BOOL)changed {NSLog(@"即將結(jié)束前");
}//已經(jīng)結(jié)束編輯時調(diào)用該協(xié)議函數(shù)
- (void)tabBarController:(UITabBarController *)tabBarController didEndCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers changed:(BOOL)changed {if (changed == YES) {NSLog(@"順序發(fā)生改變");}NSLog(@"已經(jīng)結(jié)束編輯");
}//選中控制器對象時調(diào)用該協(xié)議函數(shù)
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
//    if (tabBarController.viewControllers[tabBarController.selectedIndex] == viewController) {
//        NSLog(@"選中的視圖索引與當前傳入的視圖索引相同");
//    }NSLog(@"選中控制器對象");
}- (void)sceneDidDisconnect:(UIScene *)scene {// Called as the scene is being released by the system.// This occurs shortly after the scene enters the background, or when its session is discarded.// Release any resources associated with this scene that can be re-created the next time the scene connects.// The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
}- (void)sceneDidBecomeActive:(UIScene *)scene {// Called when the scene has moved from an inactive state to an active state.// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}- (void)sceneWillResignActive:(UIScene *)scene {// Called when the scene will move from an active state to an inactive state.// This may occur due to temporary interruptions (ex. an incoming phone call).
}- (void)sceneWillEnterForeground:(UIScene *)scene {// Called as the scene transitions from the background to the foreground.// Use this method to undo the changes made on entering the background.
}- (void)sceneDidEnterBackground:(UIScene *)scene {// Called as the scene transitions from the foreground to the background.// Use this method to save data, release shared resources, and store enough scene-specific state information// to restore the scene back to its current state.
}@end

多界面?zhèn)髦?/h2>

在 iOS 開發(fā)中，多界面之間**傳值（數(shù)據(jù)傳遞）**是非常常見的場景，比如：

• 登錄頁把用戶名傳到個人中心頁；

• 設(shè)置頁把用戶修改的偏好設(shè)置返回給主界面；

• 從商品列表點進詳情頁傳遞商品信息；

• 在這里附上學長總結(jié)的博客：

iOS多界面?zhèn)髦礯ios navigationcontroller 隔層頁面?zhèn)髦?CSDN博客

UITableView

這部分是UI中的重中之重。

UITableView是iOS開發(fā)中的一個控件，用于展示列表數(shù)據(jù)。它類似于HTML中的表格，但更加強大和靈活。UITbleView可以支持滾動、選中、插入、刪除等操作，并且可以高度自定義。

（1）創(chuàng)建UITableView實例；
（2）設(shè)置UITableView的delegate和dataSource；
（3）實現(xiàn)UITableViewDelegate和UITableViewDataSource協(xié)議中的方法；
（4）將UITableView添加到視圖中。