I have an Intel Fortran program that calls a C# function. The C# function header is a follows, it takes "stringresourcekey" and returns "stringresource" (1024 byte string) and two integers.
private void GetStringResource(
string stringresourcekey,
[In, Out, MarshalAs(UnmanagedType.LPArray, SizeConst = 1024)] byte[] stringresource,
ref int stringresourcelength_ansi,
ref int stringresourcelength_utf8)
In Fortran, I call it like this:
call GetStringResourceCallbackExternal(stringresourcekey,sStringResource,length_ansi,length_utf8)
Declarations are:
character
(len=*), intent(in) :: stringresourcekey
character (len=1024) :: sStringResource,out_string
integer :: &
length_ansi, & ! ANSI String length
length_utf8 ! Effective String length when displayed with UTF-8 encoding
This all works fine, the C# function is called, executes properly, and appears to return the intended values. Running in the debugger, I can see sStringResource,length_ansi,length_utf8 all returned with correct values and the intended string in sStringResource.
However when I try to use sStringResource, I have problems - if I write it to a file, the first part of it is garbage. If I try a simple assignment:
out_string = sStringResource
then the program crashes with an access violation. Any ideas what I'm doing wrong (or not doing)?
Mark Besley
A further development - I changed nothing in the way that the calls were done and changed nothing at the C# end, but instead declared sStringResource as an array of 256 4-byte integers:
use the same call:
call GetStringResourceCallbackExternalstringresourcekey,sStringResource,length_ansi,length_utf8)
integer, dimension(256) :: sStringResource,out_string
character (len=1024) :: mold,out_string1
out_string = sStringResource
I can assign this to another integer array without getting an access violation, and better still I can transfer the data into a character variable and write it out and get the intended output as follows:
Any idea why this fails if I declare the sStringResource as character but works fine if I declare it as integer? Is there some subtle difference in the way the data is handled between the two types?
out_string1 =
transfer(out_string,mold)
write(unlis1,"(a)")out_string1
Mark Besley
