使用相同的全局变量实例化多个 viewcontroller

Question

我如何从 viewcontroller 的列表中声明一个 viewcontroller，它有一些类似于 的变量而不重复我自己 和 没有做基础 viewcontroller？类似于：

let storyboard = UIStoryboard(name: "MainStoryboard", bundle: nil)

swtich(type){
  case "A":
    vcGeneric = storyboard.instantiateViewController(withIdentifier: "TypeAViewController") as! TypeAViewController
    break;
  case "B":
    vcGeneric = storyboard.instantiateViewController(withIdentifier: "TypeBViewController") as! TypeBViewController
    break;
}
vcGeneric.variableSame1 = "SomeValue1"
vcGeneric.variableSame2 = "SomeValue2"
vcGeneric.variableSame3 = "SomeValue3"
self.present(vcGeneric, animated: true, completion: nil)

我尝试通过声明 var vcGeneric: UIViewController 但我收到一个编译错误 Value of type "UIViewController" has no member "variableSame1"

Answer 1

使用协议定义公共属性，如下所示：

protocol CommonViewController {
    var variableSame1: String? { get set }
    var variableSame2: String? { get set }
    var variableSame3: String? { get set }
}

class ViewController1: UIViewController, CommonViewController {
    var variableSame1: String?
    var variableSame2: String?
    var variableSame3: String?
}
class ViewController2: UIViewController, CommonViewController {
    var variableSame1: String?
    var variableSame2: String?
    var variableSame3: String?
}
class ViewController3: UIViewController, CommonViewController {
    var variableSame1: String?
    var variableSame2: String?
    var variableSame3: String?
}

let storyboard = UIStoryboard(name: "MainStoryboard", bundle: nil)
var type = "A"
var vcGeneric: CommonViewController?
switch type {
case "A":
    vcGeneric = storyboard.instantiateViewController(withIdentifier: "TypeAViewController") as! ViewController1
    break;
case "B":
    vcGeneric = storyboard.instantiateViewController(withIdentifier: "TypeBViewController") as! ViewController2
    break;
default:
    vcGeneric = storyboard.instantiateViewController(withIdentifier: "TypeCViewController") as! ViewController3
    break;
}
vcGeneric.variableSame1 = "SomeValue1"
vcGeneric.variableSame2 = "SomeValue2"
vcGeneric.variableSame3 = "SomeValue3"
self.present(vcGeneric, animated: true, completion: nil)

使用相同的全局变量实例化多个 viewcontroller

Instantiate multiple viewcontroller with same global variables

uiviewcontroller

ios

swift