The C DLL has the following declaration:

ExternC int4 STDCALL func( char * ); // -> array of 32 byte strings

I can call it from C++ code using [this works!]:

char str[32] = "My String";
int4 result = func( str );

Now, I need to do this in C#. I tried something like this, but it won't
compile ("Specified unmanaged type is only valid on fields."):

[ DllImport( "capi.dll", EntryPoint = "func" ) ]
public static extern int CSharpFunc( [MarshalAs (UnmanagedType.ByValTStr,
SizeConst=32)] string s );

I realize that this isn't the way it should be done, but those of you with
experience of marshalling different types of string representations should

This should work, you don't need the MarshalAs attribute here

[ DllImport( "capi.dll", EntryPoint = "func" ) ]
public static extern int CSharpFunc(string s);

Just make sure the string you pass in is long enough if it's actually
required to be 32 chars.



Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com

Thanks Mattias!

I'm not getting this to work, but I suspect it might be another issue
altogether... Good to know this is not the cause of it.


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