实现在C＃/ C ++ / CLI中声明的接口 [英] Implementing an interface declared in C# from C++/CLI

问题描述

假设我有一个名为 IMyInterface 的C＃界面，定义如下：

Say I have a C# interface called IMyInterface defined as follows:

// C# code
public interface IMyInterface
{
  void Foo(string value);
  string MyProperty { get; }
}

假设我也有一个C ++ / CLI类， MyConcreteClass ，它实现了这个接口，其头部声明如下：

Assume I also have a C++/CLI class, MyConcreteClass, that implements this interface and whose header is declared as follows:

// C++/CLI header file
ref class MyConcreteClass : IMyInterface
{
public:

};

如何实现 Foo C / CLI头中的属性 MyProperty ？

How does one implement the method Foo and the property MyProperty in the C++/CLI header?

我的尝试会导致下列编译错误：

My attempt results in the following compile error:

错误C3766：'MyConcreteClass'必须
提供
接口方法的实现'void
IMyInterface :: Foo（System :: String ^
value）'

error C3766: 'MyConcreteClass' must provide an implementation for the interface method 'void IMyInterface::Foo(System::String^ value)'

推荐答案

public ref class MyConcreteClass : public IMyInterface
{
 public:
  virtual void __clrcall Foo(String^ value) sealed;  

  virtual property String^ __clrcall MyProperty 
         { String^ get() sealed { String::Empty; } }
};

接口需要定义为虚拟。还要注意在类解散后的公共IMY ..，它是一个略微不同的语法比C＃。

Interfaces need to be defined as virtual. Also note the "public IMy.." after the class decleration, it's a slighly different syntax than C#.

如果可以，密封接口成员以提高性能，编译器将能够比典型的虚拟成员更紧密地绑定这些方法。

If you can, seal the interface members to improve performance, the compiler will be able to bind these methods more tightly than a typical virtual members.

希望有帮助;）

我没有编译它，但看起来不错我哦...还有， __clrcall消除双重thunk性能损失的危险。

I did not compile it but looks good to me... Oh and also, defining your methods as __clrcall eliminates dangers of double thunk performance penalties.

编辑
属性的正确语法为：

edit the correct syntax for a property is:

public ref class MyConcreteClass : public IMyInterface
{
 public:
  virtual property String^ MyProperty 
  {
    String^ get() sealed { return String::Empty; };
    void set( String^ s ) sealed { };
  }
};

，或在源文件中定义时：

or, when putting the definition in the source file:

public ref class MyConcreteClass : public IMyInterface
{
 public:
  virtual property String^ MyProperty 
  {
    String^ get() sealed;
    void set( String^ s ) sealed;
  }
};

String^ MyConcreteClass::MyProperty::get()
{
  return String::Empty;
}

void MyConcreteClass::MyProperty::set( String^ )
{
  //...
}

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