UIKit框架中有各种Bar,UITabBar、UINavigationBar、UIToolbar。Bar对应的就有一些Item,tabBarItem、navigationItem、toolbarItems,再加上UIViewController、UINavigationController、UITabBarController很容易搞糊涂。我看了好久,没看明白。动手敲了下才有一点感觉。

一、联系

一个UINavigationController对应着一个UINavigationBar、UIToolbar,UIToolbar默认不显示,toolbarHidden=NO时显示。一个UITabBarController对应着一个UITabBar.一个UIViewController对应着一个tabBarItem、navigationItem和多个toolbarItems。navigationItem中可以设置左右按钮和中间视图等。

二、代码demo

1.首先代码结构 viewController1－viewController5用于生成5个tabBarItem。viewController、viewController6主要模拟登录注册，有时候需要先让用户登录注册之后才能进入。

2.代码

1.在AppDelegate.m中

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    tabBarViewController *tabVc=[[tabBarViewController alloc]init];    [self.window makeKeyAndVisible];    self.window.backgroundColor=[UIColor whiteColor];    self.window.rootViewController=tabVc;    return YES;}

 2.ViewController.m

////  ViewController.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "ViewController.h"#import "ViewController6.h" @interface ViewController () @end@implementation ViewController - (void)viewDidLoad {    [super viewDidLoad];    NSLog(@"%@ %@",NSStringFromCGRect(self.tabBarController.tabBar.frame),NSStringFromCGRect(self.navigationController.toolbar.frame));    UIButton *btn=[UIButton buttonWithType:UIButtonTypeSystem];    btn.frame=CGRectMake(100, 100, 100, 100);    [btn setTitle:@"按钮" forState:UIControlStateNormal];    [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];    UIBarButtonItem *item1=[[UIBarButtonItem alloc]initWithBarButtonSystemItem: UIBarButtonSystemItemDone target:self action:nil];    self.toolbarItems=@[item1];}-(void)btnClick:(id)sender{    ViewController6 *vc6=[[ViewController6 alloc]init];    vc6.title=@"第6页";    vc6.hidesBottomBarWhenPushed=YES;    [self.navigationController pushViewController:vc6 animated:YES];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

 3.ViewController1.m

////  ViewController1.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "ViewController1.h"#import "ViewController2.h" @interface ViewController1 () @end @implementation ViewController1 - (void)viewDidLoad {    [super viewDidLoad];        } - (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

 4.ViewController2.m

////  ViewController2.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "ViewController2.h"#import "ViewController.h"#import "navigationViewController.h" @interface ViewController2 () @end @implementation ViewController2 - (void)viewDidLoad {    [super viewDidLoad];    ViewController *vc=[[ViewController alloc]init];//    navigationViewController *nav=[[navigationViewController alloc]initWithRootViewController:vc];//    self.navigationController.toolbarHidden=NO;//    nav.toolbarHidden=NO;    [self.navigationController addChildViewController:vc];      }  - (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.} @end

 5.ViewController6.m

////  ViewController6.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "ViewController6.h" @interface ViewController6 () @end @implementation ViewController6 - (void)viewDidLoad {    [super viewDidLoad];    NSLog(@"%@ %@",NSStringFromCGRect(self.tabBarController.tabBar.frame),NSStringFromCGRect(self.navigationController.toolbar.frame));    UIBarButtonItem *item1=[[UIBarButtonItem alloc]initWithBarButtonSystemItem: UIBarButtonSystemItemAdd target:self action:@selector(btnClick:)];    self.toolbarItems=@[item1];}-(void)btnClick:(id)sender{    [self.navigationController popToRootViewControllerAnimated:YES];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.} @end

 6.tabBarViewController.m继承UITabBarController

////  tabBarViewController.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "tabBarViewController.h"#import "ViewController.h"#import "ViewController1.h"#import "ViewController2.h"#import "ViewController3.h"#import "ViewController4.h"#import "ViewController5.h"#import "navigationViewController.h" @interface tabBarViewController ()
    
      @end @implementation tabBarViewController - (void)viewDidLoad {    [super viewDidLoad];    [self steup];    self.delegate=self;    self.selectedIndex=2;    self.moreNavigationController.tabBarItem=[[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemRecents tag:1001];    self.moreNavigationController.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc]initWithTitle:@"编辑" style:UIBarButtonItemStyleDone target:self action:nil];    self.moreNavigationController.visibleViewController.navigationItem.title=@"更多功能";    self.moreNavigationController.visibleViewController.navigationItem.rightBarButtonItem.title=@"编辑"; }-(void)rightClick:(id)sender{     }-(void)steup{    ViewController *vc=[[ViewController alloc]init];    vc.title=@"第0页";    navigationViewController *nvc=[[navigationViewController alloc]initWithRootViewController:vc];    nvc.toolbarHidden=NO;    UITabBarItem *tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第0页" image:[UIImage imageNamed:@"tabbar_homepage_normal"] selectedImage:[UIImage imageNamed:@"tabbar_homepage_selected"]];    tabBarItem.badgeValue=@"2";    nvc.tabBarItem=tabBarItem;         ViewController1 *vc1=[[ViewController1 alloc]init];    vc1.title=@"第1页";    navigationViewController *nvc1=[[navigationViewController alloc]initWithRootViewController:vc1];    nvc1.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第1页" image:[UIImage imageNamed:@"tabbar_convenience_normal"] selectedImage:[UIImage imageNamed:@"tabbar_convenience_selected"]];         ViewController2 *vc2=[[ViewController2 alloc]init];    vc2.title=@"第2页";         navigationViewController *nvc2=[[navigationViewController alloc]initWithRootViewController:vc2];    nvc2.toolbarHidden=NO;    nvc2.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第2页" image:[UIImage imageNamed:@"tabbar_electrice_commerce_normal"] selectedImage:[UIImage imageNamed:@"tabbar_electrice_commerce_selected"]];              ViewController3 *vc3=[[ViewController3 alloc]init];    vc3.title=@"第3页";    navigationViewController *nvc3=[[navigationViewController alloc]initWithRootViewController:vc3];    vc3.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第3页" image:[UIImage imageNamed:@"tabbar_me_normal"] selectedImage:[UIImage imageNamed:@"tabbar_me_selected"]];         ViewController4 *vc4=[[ViewController4 alloc]init];    vc4.title=@"第4页";    navigationViewController *nvc4=[[navigationViewController alloc]initWithRootViewController:vc4];     nvc4.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第4页" image:[UIImage imageNamed:@"tabbar_convenience_normal"] selectedImage:[UIImage imageNamed:@"tabbar_convenience_selected"]];         ViewController5 *vc5=[[ViewController5 alloc]init];    vc5.title=@"第5页";    navigationViewController *nvc5=[[navigationViewController alloc]initWithRootViewController:vc5];     nvc5.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"第5页" image:[UIImage imageNamed:@"tabbar_homepage_normal"] selectedImage:[UIImage imageNamed:@"tabbar_homepage_selected"]];    // 默认的顺序     NSArray *defaultarr=@[nvc,nvc1,nvc2,nvc3,nvc4,nvc5];    // 自定义的顺序     NSMutableArray *newarr=[[NSMutableArray alloc]init];    //获取保存的title数组    NSArray *titles=[[NSUserDefaults standardUserDefaults] arrayForKey:@"vcs"];    // 第一次启动为nil    if (titles==nil) {        newarr=[defaultarr copy];    }    //根据自定义title数组 设置newarr数组    for (NSString *s in titles) {        for (navigationViewController *nvc in defaultarr) {            if ([s isEqualToString:nvc.visibleViewController.title]) {                [newarr addObject:nvc];            }        }    }    self.viewControllers=newarr;          }//UITabBarControllerDelegate//是否可以选中- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController{    return YES;}//选中某个viewController- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{//    NSLog(@"%@",viewController.title);}//开始自定义viewControllers- (void)tabBarController:(UITabBarController *)tabBarController willBeginCustomizingViewControllers:(NSArray *)viewControllers{    NSLog(@"%@",viewControllers);}//即将编辑结束- (void)tabBarController:(UITabBarController *)tabBarController willEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed{    NSLog(@"%d",changed);}//编辑结束- (void)tabBarController:(UITabBarController *)tabBarController didEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed{    //记下选择的选项顺序，方便下次启动时显示    NSMutableArray *arr=[[NSMutableArray alloc]init];    if (!changed) {        return;    }    for (UIViewController *vc in viewControllers) {        [arr addObject:vc.title];    }    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];    [defaults setObject:arr forKey:@"vcs"];    } - (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.} /*#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
    

 7.navigationViewController.m

////  navigationViewController.m//  UITabBarController////  Created by City--Online on 15/5/26.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "navigationViewController.h" @interface navigationViewController ()
    
      @end @implementation navigationViewController - (void)viewDidLoad {    [super viewDidLoad];//    if ([self respondsToSelector:@selector(setEdgesForExtendedLayout:)])//    {//        self.edgesForExtendedLayout = UIRectEdgeNone;//    }    self.navigationController.navigationBar.translucent=NO;    self.delegate=self;     }- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated{    NSLog(@"%@",viewController.title);}- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated{} - (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.} /*#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
    

 实现效果: