c的cl 编译dll,C#调用dll

extern "C" int _declspec(dllexport)testunity();
extern "C" int _declspec(dllexport)addT(int a,int b);
int testunity() { return 3;/*这是函数，里面可以写你想要实现的任何功能 */}
int addT(int a,int b){return a*2+b*3;}

set PATH=C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin;C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE;
set INCLUDE=C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\;C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Include\;
set LIB=C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\lib\;C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Lib\;C:\Program Files (x86)\Windows Kits\8.0\Lib\win8\um\x86\;

cl /c Test.cpp
link /dll Test.obj
pause

然后编译、组建。就生成了testunity.dll文件。然后再把这个文件放在你的unity工程的assert的Plugins（如果没有这个文件，那你就要新建）。

然后在unity里面新建C#脚本文件dlltest。代码如下

using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;
public class main : MonoBehaviour {
    [DllImport("uDlltest")]
    private static extern int testunity();
    [DllImport("uDlltest")]
    private static extern int addT(int a,int b);
 // Use this for initialization
 void Start () {
        print(testunity().ToString() + "," + addT(2,3).ToString());
 }
 // Update is called once per frame
 void Update () {
 }
}