IOS 点击tabbaritem跳转到一个新界面，且隐藏tabbar

先自定义一个UITabbarController，用于Storyboard中

再在MyTabbarController中实现protocol

@interface MyTabbarController : UITabBarController <UITabBarControllerDelegate>

@end

再实现代理里面的方法

@implementation MyTabbarController

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
    NSLog(@"shouldSelectViewController  %@", tabBarController.selectedViewController);
    if (viewController.tabBarItem.tag == 100) {
        DiaryViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:DIARY_VC_ID];
        [((UINavigationController *)tabBarController.selectedViewController) pushViewController:vc animated:YES];
        return NO;
    }
    return YES;
}

- (id)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        self.delegate = self;
    }
    return self;
}
@end

在要监听的tabbaritem跳转的viewcontroller中（比如点击一个item隐藏tabbar，而且有返回按钮）

则找到该tabbar，我的是父控件的tabbar，所以

- (void)viewWillAppear:(BOOL)animated {
    self.parentViewController.tabBarController.tabBar.hidden = YES;
}

点击返回按钮后回到开始所选中的tabbaritem

- (void)viewWillDisappear:(BOOL)animated {
    self.parentViewController.tabBarController.tabBar.hidden = NO;
}