[英]C#: problem loading C++ DLL
In my code, I can load "MessageBoxA" from user32.dll and use it, but if I try to load and use a function from my DLL, I get a crash. 在我的代码中,我可以从user32.dll加载“ MessageBoxA”并使用它,但是如果我尝试从DLL加载并使用一个函数,则会崩溃。
My C# code: 我的C#代码:
[DllImport("SimpleDLL.dll")]
static extern int mymean(int a, int b, int c);
[DllImport("user32.dll")]
static extern int MessageBoxA(int hWnd,
string msg,
string caption,
int type);
[...] [...]
this works 这有效
MessageBoxA(0, "Hello, World!", "This is called from a C# app!", 0);
this crashes 这崩溃
int mean = mymean(12, 14, 16);
And my C++ DLL code: SimpleDLL.cpp: 还有我的C ++ DLL代码:SimpleDLL.cpp:
extern "C" _declspec(dllexport) int mymean(int x, int y, int z)
{
return (x + y + z) / 3;
}
SimpleDLL.def:
LIBRARY "SimpleDLL"
mymean
SimpleDLL.dll is copied to the same folder as the .exe I compile from C# code. 将SimpleDLL.dll复制到与我从C#代码编译的.exe相同的文件夹中。 Using dependency walker, I can see that all necessary DLLs to load SimpleDLL.dll are present.
使用依赖关系遍历器,我可以看到存在所有用于加载SimpleDLL.dll的必需DLL。
C# uses "stdcall" calling convention by default. 默认情况下,C#使用“ stdcall”调用约定。 You've specified "C".
您已指定“ C”。 You need to either specify
您需要指定
[DllImport("SimpleDLL.dll",CallingConvention=CallingConvention.Cdecl)]
or change your c code to: 或将您的C代码更改为:
int _declspec(dllexport) stdcall mymean(int x, int y, int z)
Turns out my C# app was 64-bit (which is C# visual studio default) and my C++ DLL was 32-bit (which is C++ visual studio default). 原来我的C#应用程序是64位(这是C#Visual Studio的默认设置),而我的C ++ DLL是32位(这是C ++ Visual Studio的默认设置)。
Thanks for the tip to check the exception type, it was a badimageformatexception. 感谢您提供检查异常类型的提示,它是badimageformatexception。
Sorry - total C# newbie! 抱歉-C#新手!
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