Converting String into char *

[tmr_net]

I'm using the VC++ 2005 beta. I've seen several other suggestions on the
message boards, but none even compiled for me....here is my solution:

args[0] is a managed String, and the first argument passed into my program.
It is supposed to be a filename. I have a legacy library which is unmanaged
code that requires an old c-style char array.

System::Text::ASCIIEncoding ascii_enc;
int len = ascii_enc.GetByteCount(args[0]->ToCharArray(),0,args[0]->Length);
array<unsigned char,1> ^fname_array = gcnew array<unsigned char,1>(len+1);
ascii_enc.GetBytes(args[0],0,args[0]->Length,fname_array,0);
char *fname = new char[len+1];
for (int i=0;i<len;i++)
fname[i] = fname_array[i];
fname[len] = '\0';
old_library_call(fname);
delete fname;

1.) was there an easier way to do this?
2.) Is there anything inherently wrong with what I've done?

[tmr_net]

Well...that was actually quite helpful. The marshalling functions work...you
know it helps if you use the right namespace :)

On a side note, I think the context sensitive help in VC++ 2005 needs a
little work...

Thanks.

"rmacias" wrote:

I'm not too familiar with the VC++2005 enhancements, but I would take a look
at the Marshal class as it has methods to copy strings into unmanaged memory.
Take a look at:

http://support.microsoft.com/default...b;EN-US;311259

[rmacias]

I'm not too familiar with the VC++2005 enhancements, but I would take a look
at the Marshal class as it has methods to copy strings into unmanaged memory.
Take a look at:

http://support.microsoft.com/default...b;EN-US;311259

"tmr_net" wrote:

I'm using the VC++ 2005 beta. I've seen several other suggestions on the
message boards, but none even compiled for me....here is my solution:

args[0] is a managed String, and the first argument passed into my program.
It is supposed to be a filename. I have a legacy library which is unmanaged
code that requires an old c-style char array.

System::Text::ASCIIEncoding ascii_enc;
int len = ascii_enc.GetByteCount(args[0]->ToCharArray(),0,args[0]->Length);
array<unsigned char,1> ^fname_array = gcnew array<unsigned char,1>(len+1);
ascii_enc.GetBytes(args[0],0,args[0]->Length,fname_array,0);
char *fname = new char[len+1];
for (int i=0;i<len;i++)
fname[i] = fname_array[i];
fname[len] = '\0';
old_library_call(fname);
delete fname;

1.) was there an easier way to do this?
2.) Is there anything inherently wrong with what I've done?