标签控制器的简单使用

//下列代码为创建3个控制器分别为n1,n2,n3UINavigationController*n1=[[UINavigationController alloc]initWithRootViewController:[[FirstViewController alloc]init]];n1.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"111"image:nil tag:0];UINavigationController*n2=[[UINavigationController alloc]initWithRootViewController:[[SecondViewController alloc]init]];n2.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"222"image:nil tag:1];UINavigationController*n3=[[UINavigationController alloc]initWithRootViewController:[[ThirdViewController alloc]init]];n3.tabBarItem=[[UITabBarItem alloc]initWithTitle:@"333"image:nil tag:2];//小红点n3.tabBarItem.badgeValue=@"2";self.viewControllers=@[n1,n2,n3];self.tabBarController.selectedViewController= [self.viewControllers objectAtIndex:1];