Tabbarcontroller以編程方式添加選項卡

Question

對於我正在構建的應用程序，我的所有視圖都在情節提要中完成，並且它使用tabbarcontrolller在不同的視圖之間切換。 我有一個視圖，我想以編程方式添加到已經具有三個項目的此現有標簽欄。 如何以編程方式添加此選項卡並使其他選項卡通過情節提要。

更多：我按照您的意思做了，但是當我添加它仍然僅具有三個選項卡而不是添加第四個選項卡時，什么也沒有發生，這是我為選項卡欄控制器提供的代碼

@interface TheTabBarController ()

@end

@implementation TheTabBarController


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    UIViewController *viewController = [[CrewsViewController alloc]init];
    NSMutableArray *tempArray = [self.tabBarController.viewControllers mutableCopy];
    [tempArray addObject:viewController];
    self.tabBarController.viewControllers = tempArray;
}

@end

Answer 1

您可以通過在標簽欄控制器的viewControllers數組中添加一個新控制器來做到這一點。 因此，請以適合您的方式來實例化新控制器。 標簽欄控制器的viewControllers屬性是一個不可變的數組，因此您需要從該數組創建一個可變數組，向其中添加控制器，然后將該數組設置為標簽欄控制器的viewControllers數組。

UIViewController *newController = [[UIViewController alloc] init]; // or however is appropriate to instantiate your controller
NSMutableArray *tempArray = [self.tabBarController.viewControllers mutableCopy];
[tempArray addObject:newController];
self.tabBarController.viewControllers = tempArray;

Answer 2

嘗試這個：

- (void)viewDidLoad {
    [super viewDidLoad];

    UIViewController *view1 = [[UIViewController alloc] init];
    UIViewController *view2 = [[UIViewController alloc] init];
    UIViewController *view3 = [[UIViewController alloc] init];

    NSMutableArray *tabViewControllers = [[NSMutableArray alloc] init];
    [tabViewControllers addObject:view1];
    [tabViewControllers addObject:view2];
    [tabViewControllers addObject:view3];

    [self setViewControllers:tabViewControllers];
    //can't set this until after its added to the tab bar
    view1.tabBarItem = 
      [[UITabBarItem alloc] initWithTitle:@"view1" 
                                    image:[UIImage imageNamed:@"view1"] 
                                      tag:1];
    view2.tabBarItem = 
      [[UITabBarItem alloc] initWithTitle:@"view2" 
                                    image:[UIImage imageNamed:@"view3"] 
                                      tag:2];
    view3.tabBarItem = 
      [[UITabBarItem alloc] initWithTitle:@"view3" 
                                    image:[UIImage imageNamed:@"view3"] 
                                      tag:3];      
}

Answer 3

swift4：

func viewDidLoad() {

super.viewDidLoad()
let view1 = UIViewController()
let view2 = UIViewController()
let view3 = UIViewController()
var tabViewControllers = [AnyHashable]()
tabViewControllers.append(view1)
tabViewControllers.append(view2)
tabViewControllers.append(view3)
if let aControllers = tabViewControllers as? [UIViewController] {
    viewControllers = aControllers
}

//can't set this until after its added to the tab bar

`view1.tabBarItem = UITabBarItem(title: "view1", image: UIImage(named: "view1"), tag: 1)
view2.tabBarItem = UITabBarItem(title: "view2", image: UIImage(named: "view3"), tag: 2)
view3.tabBarItem = UITabBarItem(title: "view3", image: UIImage(named: "view3"), tag: 3)

}