Question

我正在尝试从vb.net获取DllExport到非托管c ++工作。

我在Visual Studio 2012中使用Robert Giesecke's Unmanaged Exports并试图遵循此very helpful hints。我通过在* .cpp和* .h文件所在的目录中的后期构建操作来复制.Net项目中的dll。

我用dumpbin /EXPORTS Nugget.Discovery.dll检查了我的dll，它告诉我有导出：

File Type: DLL
Section contains the following exports for \Nugget.Discovery.dll
00000000 characteristics
52554A05 time date stamp Wed Oct 09 14:20:21 2013
    0.00 version
       0 ordinal base
       2 number of functions
       2 number of names
ordinal hint RVA      name
      0    0 0000532E StartAnnouncing
      1    1 0000533E StopAnnouncing
Summary
    2000 .reloc
    4000 .rsrc
    2000 .sdata
    4000 .text

但是如果我尝试使用

在cpp文件中导入它

#import "Nugget.Discovery.dll" 
   void StartAnnouncing(int serial);

我尝试编译后出现一个IntelliSense错误和一个错误：

IntelliSense: cannot open source file "Debug/Nugget.Discovery.tlh"
error C1083: Cannot open type library file: 'nugget.discovery.dll': Fehler beim Laden der Typbibliothek/DLL.

知道我做错了吗？

祝你好运！斯蒂芬

Answer 1

作为DllExport的一部分，会生成.lib文件。您可以使用它来使用普通的C ++链接器而不是LoadLibrary / GetProcAddress。

从您发布的托管代码开始，在本机端：

extern CALLBACK void StartAnnouncingType(int serial);
extern CALLBACK int TestType(void);

int _tmain(int argc, _TCHAR* argv[])
{
    int test = TestPtr();
    StartAnnouncingPtr(1);
}

在您的非托管项目的设置中，将Nugget.Discovery.lib添加到项目属性：Configuration Properties-＆gt; Linker-＆gt; Input。并将Nugget.Discovery.dll复制到输出目录。

Answer 2

好的，感谢Hans Passant我来到了这个解决方案：

这是我在管理方面的代码：

Imports System.Runtime.InteropServices
Imports RGiesecke.DllExport

Public NotInheritable Class Beacon

Private Sub New()
End Sub

Private Shared _nuggetAnnouncement As NuggetAnnouncement

' ReSharper disable UnusedMember.Local
''' <remarks>Cannot be called from managed code!</remarks>
<DllExport("StartAnnouncing", CallingConvention.StdCall)>
Private Shared Sub StartAnnouncingNative(serial As Integer)
    StartAnnouncing(serial)
End Sub

''' <remarks>Cannot be called from managed code!</remarks>
<DllExport("Test", CallingConvention.StdCall)>
Private Shared Function TestNative() As Integer
    Return Test()
End Function
' ReSharper restore UnusedMember.Local

Public Shared Sub StartAnnouncing(serial As Integer)
    'do something
End Sub

Public Shared Function Test() As Integer
    Return 42
End Function

End Class

有趣的是，我无法从托管代码中调用标有<DllExport>的函数（即使它们是公共的）。

这是本机代码：

typedef void (CALLBACK* StartAnnouncingType)(int);
typedef int (CALLBACK* TestType)(void);

int _tmain(int argc, _TCHAR* argv[])
{
HINSTANCE dllHandle = NULL;   
StartAnnouncingType  StartAnnouncingPtr = NULL;
TestType TestPtr = NULL;
wchar_t dllNameWide[64];
int size = mbstowcs(dllNameWide, "Nugget.Discovery.dll", sizeof(dllNameWide));
dllHandle = LoadLibrary(dllNameWide);
if (NULL != dllHandle) 
{ 
  //Get pointer to our function using GetProcAddress:
  StartAnnouncingPtr = (StartAnnouncingType)GetProcAddress(dllHandle,"StartAnnouncing");
  TestPtr = (TestType)GetProcAddress(dllHandle,"Test");
  int test;
  if (NULL != TestPtr) test = TestPtr();
  int serial = 1;
  if (NULL != StartAnnouncingPtr) StartAnnouncingPtr(1);
  //Free the library:
  FreeLibrary(dllHandle);    
}
}

还有其他更好的解决方案吗？

侨！斯蒂芬

Robert Giesecke的非管理出口

2 个答案: