System::String to C-Style String

[Jonathan Porter]

Hello All - Hoping someone might be able to point me in the right direction.
I have a System::String that is part of a managed class. Within a member
function, I need to convert this String to a C-Style null terminated
character array so that it can be passed to a legacy C function. Any ideas?
I've tried putting it to a STL string first, but no luck.
Thanks!

Jon

[Ben Schwehn]

Jonathan Porter wrote:

Hello All - Hoping someone might be able to point me in the right direction.
I have a System::String that is part of a managed class. Within a member
function, I need to convert this String to a C-Style null terminated
character array so that it can be passed to a legacy C function. Any ideas?
I've tried putting it to a STL string first, but no luck.
Thanks!

Jon

you can use Marshal::StringToHGlobalUni and the corresponding ansi
function.

Example:

wchar_t* chars =
reinterpret_cast<wchar_t*>((Marshal::StringToHGlob alUni(string)).ToPointer());
hth

--
Ben
http://bschwehn.de

[Ben Schwehn]

> you can use Marshal::StringToHGlobalUni and the corresponding ansi

function.

Example:

wchar_t* chars =
reinterpret_cast<wchar_t*>((Marshal::StringToHGlob alUni(string)).ToPointer());

also, don't forget to delete the allocated memory by calling FreeHGlobal
afterwards.

[Ioannis Vranos]

Jonathan Porter wrote:

Hello All - Hoping someone might be able to point me in the right direction.
I have a System::String that is part of a managed class. Within a member
function, I need to convert this String to a C-Style null terminated
character array so that it can be passed to a legacy C function. Any ideas?
I've tried putting it to a STL string first, but no luck.
Thanks!

You may use either the Chars property, or one of the member functions
ToCharArray(), CopyTo().
Personally I would use ToCharArray() to copy to a wchar_t * or if you
are sure that you use only English characters, the Chars property to
copy in a char array, or std::string etc.

--
Ioannis Vranos

[Lokkju]

const char * to_cStr(String * str)
{
char * rStr = new char[256];
const char* c_str = (const char*)
(System::Runtime::InteropServices::Marshal::String ToHGlobalAnsi(str)).ToPointer();
strcpy(rStr,c_str);
System::Runtime::InteropServices::Marshal::FreeHGl obal(IntPtr((void*)c_str));
return rStr;
}
String * from_cStr(const char *str)
{
String *rStr;
String *c_str = new System::String(str);
rStr = c_str;
return rStr;
}

[Eric Twietmeyer]

Hi,

If you like to do things directly, you can also use the function defined in
vcclr.h, PtrToStringChars, as that takes a System::Strying and returns a
pointer (wide char, System::Char) to the underlying characters. You can
then perform your own memory management and conversion, if necessary, to
char*. However, if you just need wchar_t* then you can use directly the
returned pointer from PtrToStringChars and there is no overhead at all (you
just have to remember to pin and then release while you are using this).

-Eric

"Jonathan Porter" <Jo************@discussions.microsoft.com> wrote in
message news:B5**********************************@microsof t.com...

Hello All - Hoping someone might be able to point me in the right direction. I have a System::String that is part of a managed class. Within a member
function, I need to convert this String to a C-Style null terminated
character array so that it can be passed to a legacy C function. Any ideas? I've tried putting it to a STL string first, but no luck.
Thanks!

Jon

[Jochen Kalmbach]

=?Utf-8?B?Sm9uYXRoYW4gUG9ydGVy?= wrote:

Hello All - Hoping someone might be able to point me in the right
direction. I have a System::String that is part of a managed class.
Within a member function, I need to convert this String to a C-Style
null terminated character array so that it can be passed to a legacy C
function. Any ideas? I've tried putting it to a STL string first,
but no luck. Thanks!

There are at least tree or more different methods to do this.

See: How To Convert from System::String* to Char* in Visual C++ .NET
http://support.microsoft.com/?kbid=311259

--
Greetings
Jochen

My blog about Win32 and .NET
http://blog.kalmbachnet.de/

[Jonathan Porter]

Thanks everyone for your input, I appreciate your guidance.

Thanks again!

Jon

"Jochen Kalmbach" wrote:

=?Utf-8?B?Sm9uYXRoYW4gUG9ydGVy?= wrote:

Hello All - Hoping someone might be able to point me in the right
direction. I have a System::String that is part of a managed class.
Within a member function, I need to convert this String to a C-Style
null terminated character array so that it can be passed to a legacy C
function. Any ideas? I've tried putting it to a STL string first,
but no luck. Thanks!

There are at least tree or more different methods to do this.

See: How To Convert from System::String* to Char* in Visual C++ .NET
http://support.microsoft.com/?kbid=311259

--
Greetings
Jochen

My blog about Win32 and .NET
http://blog.kalmbachnet.de/