How to: Convert System::String to wchar_t* or char*
The latest version of this topic can be found at How to: Convert System::String to wchar_t* or char*.
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);
}
Hello
Hello