泛型介面 (C++/CLI)
套用至類別與介面上各自所屬型別參數的限制是相同的 (請參閱泛型類別 (C++/CLI))。
控制函式多載的規則，和控制泛型類別或泛型介面內的函式相同。
明確介面成員實作與建構的介面型別搭配運作的方式和與簡單的介面型別搭配時相同 (請參閱下列範例)。
如需介面的詳細資訊，請參閱介面類別。
語法
[attributes] generic <class-key type-parameter-identifier[, ...]>
[type-parameter-constraints-clauses][accesibility-modifiers] interface class identifier [: base-list] { interface-body} [declarators] ;
備註
attributes
(選擇性) 其他宣告資訊。 如需關於屬性及屬性類別的詳細資訊，請參閱屬性。
class-key
class 或 typename
type-parameter-identifier(s)
以逗號分隔的識別碼清單。
type-parameter-constraints-clauses
採用泛型型別參數的條件約束 (C++/CLI) 中指定的格式
accessibility-modifiers
(選擇性) 存取範圍修飾詞 (例如 public 和 private)。
識別碼
介面名稱。
base-list
(選擇性) 包含一或多個明確基底介面 (以逗號分隔) 的清單。
interface-body
介面成員的宣告。
declarators
(選擇性) 根據此型別的變數宣告。
範例：如何宣告和具現化泛型介面
以下範例會示範如何宣告並具現化泛型介面。 範例會宣告泛型介面 IList<ItemType>。 然後由 List1<ItemType> 和 List2<ItemType> 這兩個泛型類別分別實作。
// generic_interface.cpp
// compile with: /clr
using namespace System;
// An exception to be thrown by the List when
// attempting to access elements beyond the
// end of the list.
ref class ElementNotFoundException : Exception {};
// A generic List interface
generic <typename ItemType>
public interface class IList {
ItemType MoveFirst();
bool Add(ItemType item);
bool AtEnd();
ItemType Current();
void MoveNext();
};
// A linked list implementation of IList
generic <typename ItemType>
public ref class List1 : public IList<ItemType> {
ref class Node {
ItemType m_item;
public:
ItemType get_Item() { return m_item; };
void set_Item(ItemType value) { m_item = value; };
Node^ next;
Node(ItemType item) {
m_item = item;
next = nullptr;
}
};
Node^ first;
Node^ last;
Node^ current;
public:
List1() {
first = nullptr;
last = first;
current = first;
}
virtual ItemType MoveFirst() {
current = first;
if (first != nullptr)
return first->get_Item();
else
return ItemType();
}
virtual bool Add(ItemType item) {
if (last != nullptr) {
last->next = gcnew Node(item);
last = last->next;
}
else {
first = gcnew Node(item);
last = first;
current = first;
}
return true;
}
virtual bool AtEnd() {
if (current == nullptr )
return true;
else
return false;
}
virtual ItemType Current() {
if (current != nullptr)
return current->get_Item();
else
throw gcnew ElementNotFoundException();
}
virtual void MoveNext() {
if (current != nullptr)
current = current->next;
else
throw gcnew ElementNotFoundException();
}
};
// An array implementation of IList
generic <typename ItemType>
ref class List2 : public IList<ItemType> {
array<ItemType>^ item_array;
int count;
int current;
public:
List2() {
// not yet possible to declare an
// array of a generic type parameter
item_array = gcnew array<ItemType>(256);
count = current = 0;
}
virtual ItemType MoveFirst() {
current = 0;
return item_array[0];
}
virtual bool Add(ItemType item) {
if (count < 256)
item_array[count++] = item;
else
return false;
return true;
}
virtual bool AtEnd() {
if (current >= count)
return true;
else
return false;
}
virtual ItemType Current() {
if (current < count)
return item_array[current];
else
throw gcnew ElementNotFoundException();
}
virtual void MoveNext() {
if (current < count)
++current;
else
throw gcnew ElementNotFoundException();
}
};
// Add elements to the list and display them.
generic <typename ItemType>
void AddStringsAndDisplay(IList<ItemType>^ list, ItemType item1, ItemType item2) {
list->Add(item1);
list->Add(item2);
for (list->MoveFirst(); ! list->AtEnd(); list->MoveNext())
Console::WriteLine(list->Current());
}
int main() {
// Instantiate both types of list.
List1<String^>^ list1 = gcnew List1<String^>();
List2<String^>^ list2 = gcnew List2<String^>();
// Use the linked list implementation of IList.
AddStringsAndDisplay<String^>(list1, "Linked List", "List1");
// Use the array implementation of the IList.
AddStringsAndDisplay<String^>(list2, "Array List", "List2");
}
Linked List
List1
Array List
List2
範例：宣告泛型介面
此範例會宣告一個泛型介面 IMyGenIface，以及 IMySpecializedInt 與 ImySpecializedString 這兩個可將 IMyGenIface 特製化的非泛型介面。 接著會由 MyIntClass 和 MyStringClass 這兩個類別實作上述兩個特製化介面。 範例會示範如何將泛型介面特製化、將泛型和非泛型介面具現化，以及在介面中呼叫明確實作的成員。
// generic_interface2.cpp
// compile with: /clr
// Specializing and implementing generic interfaces.
using namespace System;
generic <class ItemType>
public interface class IMyGenIface {
void Initialize(ItemType f);
};
public interface class IMySpecializedInt: public IMyGenIface<int> {
void Display();
};
public interface class IMySpecializedString: public IMyGenIface<String^> {
void Display();
};
public ref class MyIntClass: public IMySpecializedInt {
int myField;
public:
virtual void Initialize(int f) {
myField = f;
}
virtual void Display() {
Console::WriteLine("The integer field contains: {0}", myField);
}
};
public ref struct MyStringClass: IMySpecializedString {
String^ myField;
public:
virtual void Initialize(String^ f) {
myField = f;
}
virtual void Display() {
Console::WriteLine("The String field contains: {0}", myField);
}
};
int main() {
// Instantiate the generic interface.
IMyGenIface<int>^ myIntObj = gcnew MyIntClass();
// Instantiate the specialized interface "IMySpecializedInt."
IMySpecializedInt^ mySpIntObj = (IMySpecializedInt^) myIntObj;
// Instantiate the generic interface.
IMyGenIface<String^>^ myStringObj = gcnew MyStringClass();
// Instantiate the specialized interface "IMySpecializedString."
IMySpecializedString^ mySpStringObj =
(IMySpecializedString^) myStringObj;
// Call the explicitly implemented interface members.
myIntObj->Initialize(1234);
mySpIntObj->Display();
myStringObj->Initialize("My string");
mySpStringObj->Display();
}
The integer field contains: 1234
The String field contains: My string