好了，好了，我现在觉得愚蠢。

Okay, well, I now feel dumb.

事实证明，这个问题我是有（这是我解决了一个几个星期前 - 只是抽时间去更新这个答案）是，我已经包含头文件（见克里斯的答案是），但我就没'牛逼实际上包括CPP文件（里面是空的以外，包括头文件）。

It turns out that the problem I was having (which I solved a couple weeks ago - just got around to updating this answer) was that I had included the header file (see Chris' answer for that), but I hadn't actually included the CPP file (which is empty other than including the header file).

在我这样做，该DLL编译正确，我可以调用C ++函数从我的C＃code（使用C ++ / CLI）。

Once I did this, the DLL compiled correctly and I could call the C++ functions (using C++/CLI) from my C# code.