Objective c 从Swift中的非泛型函数调用泛型函数
Objective c 从Swift中的非泛型函数调用泛型函数,objective-c,swift,generics,interop,Objective C,Swift,Generics,Interop,MMCondition是Swift中定义的协议,但与Objective-C(用@objc注释)互操作 我有以下代码: // addCondition cannot be generic as I want it to be accessible from Objective-C as well. public func addCondition(condition: MMCondition) { // How do I initialize OperationConditionImple
MMCondition
是Swift中定义的协议,但与Objective-C(用@objc注释)互操作
我有以下代码:
// addCondition cannot be generic as I want it to be accessible from Objective-C as well.
public func addCondition(condition: MMCondition) {
// How do I initialize OperationConditionImplementer here?
let operationCondition = OperationConditionImplementer(condition: condition) // doesn't compile
// Error: Cannot invoke initializer for type 'OperationConditionImplementer<T>' with an argument list of type '(condition: MMCondition)'
// Can I use condition.dynamicType to init OperationConditionImplementer somehow?
}
struct OperationConditionImplementer<T: MMCondition> {
let condition: T
static var name: String {
return "Silent<\(T.name)>"
}
static var isMutuallyExclusive: Bool {
return T.isMutuallyExclusive
}
init(condition: T) {
self.condition = condition
}
}
//addCondition不能是泛型的,因为我希望它也可以从Objective-C访问。
公共函数添加条件(条件:MMCondition){
//如何在此处初始化OperationConditionImplementer?
让operationCondition=OperationConditionImplementer(条件:条件)//不编译
//错误:无法使用类型为“(条件:MMCondition)”的参数列表调用类型为“OperationConditionImplementer”的初始值设定项
//我能否以某种方式使用condition.dynamicType初始化OperationConditionImplementer?
}
结构操作条件实现器{
让条件:T
静态变量名:String{
返回“静默”
}
静态var是唯一的:Bool{
返回T.isMutuallyExclusive
}
初始(条件:T){
自我状态
}
}
从Objective-C中,您不能使用中所述的泛型
您可以访问类或协议中任何
标记为@objc属性,只要它与
目标C。这不包括仅Swift功能,如所列功能
在这里:
- 仿制药
@objc protocol MMCondition {
static var name: String { get }
static var isMutuallyExclusive: Bool { get }
}
struct OperationConditionImplementer {
let condition: MMCondition
var name: String {
return "Silent<\(condition.dynamicType.name)>"
}
var isMutuallyExclusive: Bool {
return condition.dynamicType.isMutuallyExclusive
}
init(condition: MMCondition) {
self.condition = condition
// Here decide comparing types
if condition.dynamicType === ExampleCondition.self {
print(condition.dynamicType.name)
}
}
}
您将看到打印的“ExampleCondition”
如果最终切换到纯Swift,则需要在初始化操作条件实施器时指定T
您可以将addCondition
方法定义为:
func addCondition<T: MMCondition>(condition: T) {
let a = OperationConditionImplementer<T>(condition: condition)
}
func addCondition(条件:T){
设a=OperationConditionImplementer(条件:条件)
}
因为通用类的Swift 2.0实例可以实现Objective-C协议。我认为不可能的是让结构实现协议。事实上,我希望您的协议可能需要继承自NSObjectProtocol,以便在Objective-C中可用,这将阻止您使用结构或枚举实现协议
您还正确地提到,您不能从Objective-C访问泛型函数
有关使用泛型实现Objective-C协议的具体示例,请查看 addCondition不能是泛型的,因为我希望它也可以从Objective-C访问。实际上,您不能在Obj-C中使用泛型,编辑回答这是否意味着在我的示例中func addCondition(没有泛型)不能正确实例化OperationConditionImplementer?正确,您需要类型来实例化实现者,这不能在运行时决定。一个选项是,正如您所建议的,使用初始值设定项构建它并检查其中的类型,但是您需要完全删除所有泛型内容,以便从对象中使用它,因为它是完全独占的,并且名称是静态的,这种方法会带来一系列不同的问题。
class ExampleCondition: NSObject, MMCondition {
static var name: String = "ExampleCondition"
static var isMutuallyExclusive: Bool = false
}
let example = OperationConditionImplementer(condition: ExampleCondition())
func addCondition<T: MMCondition>(condition: T) {
let a = OperationConditionImplementer<T>(condition: condition)
}