Question

我使用了以下数字:

[DllImport(@"someDLL.dll", CallingConvention = CallingConvention.Cdecl)]
private static extern UINT64 someFunc(int arga, int argb, int argc);

I m 称其职能如下:

someFunc(0,0,1);

档案中:

extern "C" __declspec(dllexport) UINT64 someFunc(int arga, int argb, int argc);

cpp:

UINT64 someFunc(int arga, int argb, int argc)
{
   ...
}

In the C++ code I receive weird values (such as 1218628, 20140292, 1219020).

任何想法为什么?

Answer 1

You didn t show the C++ code so I don t see the problem in your code. So, I tried recreating it myself. I created a C# WPF project which calls into a DLL.

C#:

        [DllImport(@"c:usersownerdocumentsvisual studio 2010ProjectsMyDllReleaseMyDll.dll",
            CallingConvention = CallingConvention.Cdecl)]
        private static extern UInt64 someFunc(int arga, int argb, int argc); 

        private void DoIt_Click(object sender, RoutedEventArgs e)
        {
            UInt64 val = someFunc(0, 0, 1);
            ResultLabel.Content = val.ToString();
        }

C++ DLL:

extern "C" __declspec(dllexport) unsigned __int64 someFunc(int arga, int argb, int argc)
{
    CString s;
    s.Format(L"%d	%d	%d", arga, argb, argc);
    AfxMessageBox(s);
    return arga + argb + argc;
}

C++的电文箱显示,预计01份,C#代码按预期恢复1份。

Answer 2

如果你能够,在___次电话中,使用__std打字器而不是__cdecl,则使用CL,进行掩蔽清理,是使用C车窗的标准方法。

It is also a good behaviour to specify the calling convention in your C code, both for readability and because C++ project settings can specify what calling convention use by default.

如要明确确定第__cdecl号,或许是第++号汇编员正在使用第__号招贴汇编这一文件。

extern "C" __declspec(dllexport) UINT64 __cdecl someFunc(int arga, int argb, int argc);

友情链接