两种常见的UITabBarController+UINavigationController模式分析比较

绝大部分软件都采用了UITabBarController+UINavigationController的设计模式,这是一种很主流很经典的设计方式,而另外一种UINavigationController+UITabBarController也是一种非常灵活的模式

方式一:TabBarController的viewControllers + 一个NavigationController

创建过程大概如下(关键代码):

AppDelegate.m

TabBarController *tabVC = [[TabBarController alloc]init];
//全局就这一个导航控制器
UINavigationController *nav =[[UINavigationController alloc] initWithRootViewController:tabVC];
self.window.rootViewController = nav;

TabBarController.m

- (void)viewDidLoad {
    [super viewDidLoad];
    [self addChildVc:[[ChatViewController alloc] init] title:@"Chat" image:@"tabbar_home" selectedImage:@"tabbar_home_selected"];
    [self addChildVc:[[ContactsListViewController alloc] init] title:@"Contact" image:@"tabbar_contacts" selectedImage:@"tabbar_contacts_selected"];
    [self addChildVc:[[MoreViewController alloc] init] title:@"More" image:@"tabbar_more" selectedImage:@"tabbar_more_selected"];
    [self addChildVc:[[ProfileViewController alloc] init] title:@"Profile" image:@"tabbar_profile" selectedImage:@"tabbar_profile_selected"];
}

- (void)addChildVc:(UIViewController *)childVc title:(NSString *)title image:(NSString *)image selectedImage:(NSString *)selectedImage
{
    childVc.title = title;
    childVc.tabBarItem.image = [UIImage imageNamed:image];
    childVc.tabBarItem.selectedImage = [[UIImage imageNamed:selectedImage] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    [self addChildViewController:childVc];
}

方式二:TabBarController的viewControllers + 多个NavigationController

创建过程大概如下(关键代码):

AppDelegate.m

TabBarController *tabVC = [[TabBarController alloc]init];
self.window.rootViewController = tabVC;

TabBarController.m

- (void)viewDidLoad {
    [super viewDidLoad];
    [self addChildVc:[[ChatViewController alloc] init] title:@"Chat" image:@"tabbar_home" selectedImage:@"tabbar_home_selected"];
    [self addChildVc:[[ContactsListViewController alloc] init] title:@"Contact" image:@"tabbar_contacts" selectedImage:@"tabbar_contacts_selected"];
    [self addChildVc:[[MoreViewController alloc] init] title:@"More" image:@"tabbar_more" selectedImage:@"tabbar_more_selected"];
    [self addChildVc:[[ProfileViewController alloc] init] title:@"Profile" image:@"tabbar_profile" selectedImage:@"tabbar_profile_selected"];
}

- (void)addChildVc:(UIViewController *)childVc title:(NSString *)title image:(NSString *)image selectedImage:(NSString *)selectedImage
{
    childVc.title = title;
    childVc.tabBarItem.image = [UIImage imageNamed:image];
    childVc.tabBarItem.selectedImage = [[UIImage imageNamed:selectedImage] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    // 每一个控制器都是导航控制器
    UINavigationViewController *navigationVc = [[UINavigationViewController alloc] initWithRootViewController:childVc];
    [self addChildViewController:navigationVc];
}

对比分析

第一种方式:

导航控制器上的title不能和tabbar上面的同步,需要手动单独设置,比如可以在控制器的viewWillAppear:方法里面设置.

navigationItem的左右按钮和颜色可能各不相相同,也需要在viewWillAppear:里切换设置.可能后续的界面跳转也需要在此方法里面设置.

第二种方式:

tabbar上的标题默认会直接同步到导航控制器上.

每个界面都有自己的导航控制器, 界面跳转都有自己的栈, 可能会更加灵活.