[C# Tip]How to: Convert System::String to wchar_t* or char*

(MSDN)You can use PtrToStringChars in Vcclr.h to convert ​​String​​ to native wchar_t * or char *. This always returns a wide Unicode string pointer because CLR strings are internally Unicode. You can then convert from wide as shown in the following example.

Example

// convert_string_to_wchar.cpp

// compile with: /clr

#include < stdio.h >

#include < stdlib.h >

#include < vcclr.h >

using namespace System;

int main() {

String ^str = "Hello";

// Pin memory so GC can't move it while native function is called

pin_ptr<const wchar_t> wch = PtrToStringChars(str);

printf_s("%S\n", wch);

// Conversion to char* :

// Can just convert wchar_t* to char* using one of the

// conversion functions such as:

// WideCharToMultiByte()

// wcstombs_s()

// ... etc

size_t convertedChars = 0;

size_t  sizeInBytes = ((str->Length + 1) * 2);

errno_t err = 0;

char    *ch = (char *)malloc(sizeInBytes);

err = wcstombs_s(&convertedChars,

ch, sizeInBytes,

wch, sizeInBytes);

if (err != 0)

printf_s("wcstombs_s  failed!\n");

printf_s("%s\n", ch);

}

Output

Hello

Hello