P/Invoke Interop Problem

hi all,

i've been working on program control special type of scientific camera! i'm trying use camera's sdk written in unmanaged c++, , i'm trying interoperate sdk using c#.

everything going till got work function had char* arguments, unmanaged method signature is:

 

 

int flilistfirst(int *domain, char *filename, size_t fnlen, char *name, size_t namelen); 

 

i first tried use following managed signature:

 

 [dllimportattribute(@strpath, entrypoint = "flilistfirst", callingconvention = callingconvention.stdcall)]

 public static extern int flilistfirst(out int domain, out intptr filename,  [system.runtime.interopservices.marshalasattribute(system.runtime.interopservices.unmanagedtype.u4)] uint fnlen, out intptr name,  [system.runtime.interopservices.marshalasattribute(system.runtime.interopservices.unmanagedtype.u4)] uint namelen);

 

when marshalled returned intptrs string using marshal.ptrtostringauto() converted string looked strange, intptr pointing wrong address.

i tried change intptrs stringbuilder, result stackoverflowexception! current managed signature i'm trying worked is:

 

 

 [dllimportattribute(@strpath, entrypoint = "flilistfirst", callingconvention = system.runtime.interopservices.callingconvention.stdcall)]

 public static extern int flilistfirst(out int domain, [marshalas(unmanagedtype.lpwstr)] out stringbuilder filename, [system.runtime.interopservices.marshalasattribute(unmanagedtype.u4)] uint fnlen, [marshalas(unmanagedtype.lpwstr)] out stringbuilder name, [system.runtime.interopservices.marshalasattribute(unmanagedtype.u4)] uint namelen);

i should mention tried pair stringbuilders whith lpstr too, once didn't pair them unmanaged type @ all, in cases got exception!

since i'm new p/invoke, seems can't figure out going wrong!

 

i appreciate help, friends!

 

ok, problem solved, removed out keyword before stringbuilder definitions, , it's working!

 

.NET Framework  >  Common Language Runtime Internals and Architecture