idl chapter (in c++) duty take c-style array c#

May 15, 2011

i am operative an existent formula bottom finished adult com interfaces combined c++ c# front end. there new functionality needs added, i'm carrying cgange com portions. sole case, i need pass an array (allocated c#) member filled.

what i means pass an array int slight c#, something like:

// preferred c# signature
void getfoo(int buffersize, int[] buffer);

// preferred usage
int[] blah = ...;
getfoo(blah.length, blah);

a integrate wrenches works:

c++/cli managed c++ can't used (com finished divided case).

the c# side can't collected /unsafe (using organise allowed).

the com interface wholly used (an wholly ever used) c# part, i'm reduction concerned interoperability com consumers. portability between 32 64 bit also pleasantness (everything being collected run 32 bit machine, formula generators converting pointers integers). eventually, transposed only c++/cli, nonetheless ways off.

my initial attempt

is something identical to:

hresult getfoo([in] int buffersize, [in, size_is(buffersize)] int buffer[]);

and cost tlb construction (seems reasonable):

hresult _stdcall getfoo([in] int buffersize, [in] int* buffer);

which alien c# (not reasonable):

void getfoo(int buffersize, ref int buffer);

which i could with

int[] b = ...;
fixed(int *bp = &b[0])
{
    getfoo(b.length, ref *bp);
}

...except i can't accumulate /unsafe.

at moment

i am using:

hresult getfoo([in] int buffersize, [in] int_ptr buffer);

which imports as:

void getfoo(int buffersize, int buffer);

and i need use like:

int[] b = ...;
gchandle bpin = gchandle.alloc(b, gchandletype.pinned);
try
{
    getfoo(b.length, (int)marshal.unsafeaddrofpinnedarrayelement(b, 0));
}
finally
{
    bpin.free();
}

which works..., nonetheless i'd cleaner way.

so, doubt is

is there an idl construction permitted c# import tlb generator case? not, finished c# side small safer?

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