一、源起

小編最近在使用App的時(shí)候侥涵，經(jīng)常遇到UITabBarController為根控制器跳轉(zhuǎn)到另一個(gè)UITabBarController.這種作為可以盡最大可能性的細(xì)分模塊。經(jīng)過幾次實(shí)驗(yàn)和瀏覽相關(guān)App。最終決定了2種方案。

二寸认、實(shí)現(xiàn)關(guān)鍵點(diǎn)

1、實(shí)現(xiàn)UITabBarControllerDelegate

    @interface YITabBarController ()
    @end
    @implementation YITabBarController
    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view.
        self.delegate = self;
    }
    @end

2串慰、實(shí)現(xiàn) -tabBarController:shouldSelectViewController:方法

    - (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController{
   
 }

三偏塞、實(shí)現(xiàn)方案

第一種實(shí)現(xiàn) 使用模態(tài)視圖

使用模態(tài)視圖并修改模態(tài)視圖的彈出動(dòng)畫為push的形式

    - (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
        //4是泡泡頁面
        if ([viewController isEqual:[tabBarController.viewControllers objectAtIndex:4]]) {
            SecondTabBarController * vc = [[SecondTabBarController alloc] init];
            CATransition * ansition = [CATransition animation];
            [ansition setDuration:0.25f];
            [ansition setType:kCATransitionMoveIn];
            [ansition setSubtype:kCATransitionFromRight];
            [[UIApplication sharedApplication].keyWindow.layer addAnimation:ansition forKey:nil];
            [self presentViewController:vc animated:NO completion:nil];
            return NO;
        }
        return YES;
    }

模態(tài)視圖的返回

    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view.
        self.view.backgroundColor = [UIColor groupTableViewBackgroundColor];
        UIBarButtonItem * leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:(UIBarButtonItemStyleDone) target:self action:@selector(back)];
        self.navigationItem.leftBarButtonItem = leftBarButtonItem;
    }
    - (void)back {
            CATransition * ansition = [CATransition animation];
            [ansition setDuration:0.25f];
            [ansition setType:kCATransitionMoveIn];
            [ansition setSubtype:kCATransitionFromLeft];
            [[UIApplication sharedApplication].keyWindow.layer addAnimation:ansition forKey:nil];
            [self dismissViewControllerAnimated:NO completion:nil];
    }

效果如下圖(gif圖，如果不會(huì)動(dòng)請(qǐng)刷新)

iyiqi_gif1.gif

弊端
gif圖可能看的不是很清楚邦鲫。
弊端就是在push 或者 pop動(dòng)畫執(zhí)行時(shí)會(huì)看到黑影閃過灸叼，如果要求不高的可以使用這個(gè)神汹。
為了解決這個(gè)問題，我們引出第二種實(shí)現(xiàn)方案.

第二種實(shí)現(xiàn) 使用UINavigationController push的形式

導(dǎo)航欄push的方式
還是先實(shí)現(xiàn)前置條件里的代碼

接著實(shí)現(xiàn)以下代碼

    - (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
        //4是泡泡頁面
        if ([viewController isEqual:[tabBarController.viewControllers objectAtIndex:4]]) {
            SecondTabBarController * vc = [[SecondTabBarController alloc] init];
            vc.hidesBottomBarWhenPushed = YES;
            UINavigationController * nav = tabBarController.viewControllers[tabBarController.selectedIndex];
            [nav pushViewController:vc animated:YES];
            return NO;
        }
        return YES;
    }

注意事項(xiàng)
要在第二個(gè)TabBar里隱藏掉最外層的導(dǎo)航欄古今，否則將可能出現(xiàn)2個(gè)導(dǎo)航欄的效果

    - (void)viewWillAppear:(BOOL)animated {
        [super viewWillAppear:animated];
        [self.navigationController setNavigationBarHidden:YES animated:animated];
    }
    - (void)viewWillDisappear:(BOOL)animated {
        [super viewWillDisappear:animated];
        [self.navigationController setNavigationBarHidden:NO animated:animated];
    }

一定要使用 -setNavigationBarHidden:animated: 這個(gè)方法來顯示隱藏導(dǎo)航欄屁魏，并且動(dòng)畫效果不要寫YES或者NO要用animated，否則將會(huì)出現(xiàn)導(dǎo)航欄黑邊閃一下或者手勢(shì)時(shí)出現(xiàn)黑邊的情況捉腥。
效果如下圖(gif圖氓拼，如果不會(huì)動(dòng)請(qǐng)刷新)

iyiqi_gif2.gif