convert from managed String to unmanaged char

[keith]

In managed C++, there is variable String *s. The variable got value from a
C# assembly. Then I need to convert it into char *c in order to call
an external function in a dll that accepts parameter func(char c[]).

How to convert from String *s to char *c?

thanks

Keith

[William DePalo [MVP VC++]]

"keith" <ke***@discussions.microsoft.com> wrote in message
news:AD**********************************@microsof t.com...

In managed C++, there is variable String *s. The variable got value from a
C# assembly. Then I need to convert it into char *c in order to call
an external function in a dll that accepts parameter func(char c[]).

How to convert from String *s to char *c?

This gets you a pointer to the (wide) characters that comprise the string:

#include <vcclr.h>

wchar_t __pin *pStr = PtrToStringChars(s);

At that point you'll need to convert to ANSI. Check the docs for conversion
functions such as wcstombs() or WideCharToMultiByte().

Regards,
Will

[Rambuncle]

using namespace System::Runtime::InteropServices;
const char* FileStr = (const char*)(Marshal::StringToHGlobalAnsi(in_file)).ToPo inter();
// Do what you want with FileStr
Marshal::FreeHGlobal(IntPtr((void*)FileStr));

That is what I did, and it seemed to work fine

"keith" wrote:

In managed C++, there is variable String *s. The variable got value from a
C# assembly. Then I need to convert it into char *c in order to call
an external function in a dll that accepts parameter func(char c[]).

How to convert from String *s to char *c?

thanks

Keith

[William DePalo [MVP VC++]]

"Rambuncle" <Ra*******@discussions.microsoft.com> wrote in message
news:C7**********************************@microsof t.com...

using namespace System::Runtime::InteropServices;
const char* FileStr = (const char*)(Marshal::StringToHGlobalAnsi(in_file)).ToPo inter(); // Do what you want with FileStr
Marshal::FreeHGlobal(IntPtr((void*)FileStr));

That is what I did, and it seemed to work fine

Yup, it does. Just make sure to free the memory when you are done.

Regards,
Will