在COM接口中包含非托管类型属性

Question

我正在用Oxygene为COM可调用的包装类编写COM接口。我不知道如何将System.Decimal属性作为货币(原生COM类型)来传递，因为Oxygene编译器不允许使用Delphi.NET的语法。

下面是我如何在Delphi.NET中成功地做到这一点的一个简单的例子

[ComVisible(True)]
IVarious = interface(IInterface)
['{2DBF9ACD-1574-4BE4-812A-5D0B8E9AA025}']
  function get_MyString: String;
  procedure set_MyString(strValue: String);
  [return: MarshalAs(UnmanagedType.Currency)]
  function get_MyAmount: System.Decimal;
  procedure set_MyAmount([MarshalAs(UnmanagedType.Currency)] curValue: System.Decimal);
  property MyString: String read get_MyString write set_MyString;
  property MyAmount: System.Decimal read get_MyAmount write set_MyAmount;
end;

// In Delphi.NET the implementing class only needed to have the methods, not the properties
[ComVisible(False)]
[ClassInterface(ClassInterfaceType.None)]
TVarious = class(TObject, Various)
private
  FMyString: string;
  FMyAmount: System.Decimal;
public
  function get_MyString: String;
  procedure set_MyString(strValue: String);
  [return: MarshalAs(UnmanagedType.Currency)]
  function get_MyAmount: System.Decimal;
  procedure set_MyAmount([MarshalAs(UnmanagedType.Currency)] curValue: System.Decimal);
end;

(我不想展示TVarious、getter和setter方法实现，因为它们非常明显。)

我知道Oxygene不需要接口来声明getter & setter方法。在我看来，它实际上不允许您有getter & setter方法。所以，我能把它转换成Oxygene (到目前为止)的唯一方法是：

[ComVisible(True)]
[Guid('2DBF9ACD-1574-4BE4-812A-5D0B8E9AA025')]
IVarious = interface
  property MyString: String read write;
  property MyAmount: System.Decimal read write;
end;

[ComVisible(False)]
[ClassInterface(ClassInterfaceType.None)]
TVarious = class(IVarious)
public
  property MyString: String;
  property MyCurrency: System.Decimal;
end;

但我的问题是，我还没有弄清楚如何将MarshalAs(UnmanagedType.Currency)属性包含到这些声明中。

有关如何在接口中包含此COM属性的帮助将不胜感激。

Answer 1

你试过这个吗？

[ComVisible(True)]
[Guid('2DBF9ACD-1574-4BE4-812A-5D0B8E9AA025')]
IVarious = interface
  property MyString: String read write;
  property MyAmount: System.Decimal read write;
end;

[ComVisible(False)]
[ClassInterface(ClassInterfaceType.None)]
TVarious = class(IVarious)
public
  property MyString: String;
  [var: MarshalAs(UnmanagedType.Currency)]
  property MyAmount: System.Decimal;
end;

我没有办法测试这个，但你能看看它是否有效吗？

诚挚的问候,

耶伦