由于难度不大，直接上代码了，看一遍基本就明白思路了

1.创建一个tabBarViewController

.m文件

#import "SSTabBarViewController.h"
#import "constant.h"@interface SSTabBarViewController ()@end@implementation SSTabBarViewController-(instancetype)init
{self = [super init];if (self) {UINavigationController * newNavigationController = [WPUtil getViewControllerWithIdentifier:@"new" storyboardName:@"New"];UINavigationController * alreadyNavigationController = [WPUtil getViewControllerWithIdentifier:@"already" storyboardName:@"Already"];UINavigationController * myNavigationController = [WPUtil getViewControllerWithIdentifier:@"my" storyboardName:@"My"];UINavigationController * moreNavigationController = [WPUtil getViewControllerWithIdentifier:@"more" storyboardName:@"More"];self.viewControllers = @[newNavigationController, alreadyNavigationController, myNavigationController, moreNavigationController];UITabBarItem * newItem = self.tabBar.items[0];newItem.title = @"新订单";newItem.image = [[UIImage imageNamed:@"xindingdan_hui"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];newItem.selectedImage = [[UIImage imageNamed:@"xindingdan_lv"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];UITabBarItem * alreadyItem = self.tabBar.items[1];alreadyItem.title = @"已处理";alreadyItem.image = [[UIImage imageNamed:@"yichuli_hui"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];alreadyItem.selectedImage = [[UIImage imageNamed:@"yichuli_lv"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];UITabBarItem * myItem = self.tabBar.items[2];myItem.title = @"我的";myItem.image = [[UIImage imageNamed:@"wode_hui"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];myItem.selectedImage = [[UIImage imageNamed:@"wode_lv"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];UITabBarItem * moreItem = self.tabBar.items[3];moreItem.title = @"更多";moreItem.image = [[UIImage imageNamed:@"gengduo_hui"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];moreItem.selectedImage = [[UIImage imageNamed:@"gengduo_lv"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];}return self;
}-(void)viewDidLoad {[super viewDidLoad];
}@end

2.在appDelegate中设置，将window的rootView设置为我们的tabBar

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];SSTabBarViewController * tabBar = [[SSTabBarViewController alloc] init];self.window.rootViewController = tabBar;[self.window makeKeyAndVisible];return YES;
}

注：这里一定要记得初始化window，否则会造成黑屏

3.设置程序启动后默认进入的viewController

4.注意：如果设置了navigationController此时该viewController的storyboard ID要设置在navigationController上

5.顺便说一句，当隐藏tabBar的时候，如果controllerView上有tableView，那么此时你需要用下面这段代码来让tableView顶部不留下空白部分:

self.automaticallyAdjustsScrollViewInsets = NO;