Few questions on interopability - C++ exported functions to use in C#

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C++

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interop

Hi All,

I have a code written in C++ which i need to consume in C# Application.
Below are the syntax's of the two methods which i need to use in my C# application:

long __declspec (dllimport) MyMethod1(const wchar_t* inputFileName, const wchar_t* outputFileName)

__declspec (dllimport) int __stdcall MyMethod2(void ** pMyVoidPtr, MY_CUSTOM_STRUCT* pMyCustomStruct);

I could use them in my C++ Application as below:

MyMethod1(_T("C:\\InputFile.txt"), _T("C:\\OutputFile.txt"));

MY_CUSTOM_STRUCT myCustomStruct;

void* pVoidPtr = NULL;

MyMethod2(&pVoidPtr, &myCustomStruct);

In C++ Application, i could get the desired results. But in C# Application, the Pointer pVoidPtr always returns NULL.

I have tried using ref, out IntPtr as parameters but everything failed.

Could anyone provide me the syntax for the same in C# Application (For both the methods)?

Thanks and Regards,
Kishor Reddy

What I have tried:

[DllImport("Exported Dll Path")]
long static extern MyMethod1(string strInputName, string strOutputName);

[DllImport("Exported Dll Path")]
int static extern MyMethod2(out IntPtr pVoidPtr, MY_CUSTOM_STRUCT myCustomStruct);

[DllImport("Exported Dll Path")]
int static extern MyMethod2(out IntPtr pVoidPtr, IntPtr myCustomStruct);