C#向C++ DLL传递参数出现参数顺序和个数对应错误的问题

C++DLL .h中

_declspec(dllexport) float _stdcall eAdd(const float fxw, const float fyw);
    _declspec(dllexport) float _stdcall qAdd(float aw, float bw);

.cpp中
float _stdcall RealDLL::eAdd(const float fxw, const float fyw)
{
    cout << fxw << endl;
    cout << fyw << endl;
    return fxw+fyw;
}
float _stdcall RealDLL::qAdd(float aw, float bw)
{
    cout << aw << endl;
    cout << bw << endl;
    return aw + bw;
}

C#中

    [DllImport(@"CFirstDLL.dll", EntryPoint = "eAdd", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
    extern static float eAdd(float fx, float fy);

    [DllImport(@"CFirstDLL.dll", EntryPoint = "qAdd", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
    extern static float qAdd(float a, float b);
              static void Main(string[] args)
    {
        float Py = 4.55F, Pz = 6.66F, Prx = 7.75F, Pry = 8.88f,;

        float res = eAdd(Py, Pz);
        float srf = qAdd(Prx, Pry);
    }

结果：

问题： 两个函数的第一个参数都传输错误，C#中第二参数的值传给了DLL里的第一个参数，DLL中第二个参数为0。试了网上的好多种方法仍然没解决，求各位大佬帮忙看看是咋回事？

c++程序编译成32bit
C#强制也编译成32bit