Ios 实例成员不能用于类型'；AppDelegate'；

我在AppDelegate类中声明了一个变量itemGlobalArray，如下所示

var itemGlobalArray = NSMutableArray()

if (AppDelegate.itemGlobalArray).count > 0 //Gives error here
        {
            let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "BasketVC") as? BasketVC
            self.navigationController?.pushViewController(vc!, animated: true)
        }
        else {
            let alert = UIAlertController(title: "Alert", message: "cart Empty", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
                switch action.style{
                case .default:
                    print("default")
                    
                case .cancel:
                    print("cancel")
                    
                case .destructive:
                    print("destructive")
                    
                    
                }}))
            self.present(alert, animated: true, completion: nil)
        }

并尝试在下面这样的视图控制器中使用它

var itemGlobalArray = NSMutableArray()

if (AppDelegate.itemGlobalArray).count > 0 //Gives error here
        {
            let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "BasketVC") as? BasketVC
            self.navigationController?.pushViewController(vc!, animated: true)
        }
        else {
            let alert = UIAlertController(title: "Alert", message: "cart Empty", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
                switch action.style{
                case .default:
                    print("default")
                    
                case .cancel:
                    print("cancel")
                    
                case .destructive:
                    print("destructive")
                    
                    
                }}))
            self.present(alert, animated: true, completion: nil)
        }

---

您必须像静态成员一样声明它，静态成员可以在没有实例的情况下使用：

class AppDelegate {
    static var itemGlobalArray = NSMutableArray()

    //...
}

您可以在您的案例中使用它：

if (AppDelegate.itemGlobalArray).count > 0 { ... }

---

我认为更好的方法是使用

UIApplication.shared.delegate作为？AppDelegate

在

var