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Passing an object array between COM and .NET

Hi
I'm creating a .NET dll, which I will use in VB 6. I have no problem
declaring methods, which will take a single Object, String, Integer and so on
as a parameter. I manage even to transfer arrays of Strings and integer, but
I fail to pass an array of Objects in a parameter. How do I declare a method,
where one of the parameters is an Object array, in .NET, which I will use in
VB6?
Regards
/Niklas

Nov 16 '05 #1
2 1836
Niklas,

You should be able to declare it with the MarshalAs attribute, like
this:

void DoSomething([MarshalAs(Unman agedType.SafeAr ray,
SafeArraySubTyp e=VarType.VT_DI SPATCH)] ref object[] array)
{
// Do something with the array.
}

I'm not sure about the ref, you might need it for VB6 (you can try it
with and without).

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m

"Niklas" <Ni****@discuss ions.microsoft. com> wrote in message
news:85******** *************** ***********@mic rosoft.com...
Hi
I'm creating a .NET dll, which I will use in VB 6. I have no problem
declaring methods, which will take a single Object, String, Integer and so
on
as a parameter. I manage even to transfer arrays of Strings and integer,
but
I fail to pass an array of Objects in a parameter. How do I declare a
method,
where one of the parameters is an Object array, in .NET, which I will use
in
VB6?
Regards
/Niklas

Nov 16 '05 #2
Hi
Thank you. The VT_DISPATCH worked. The unmanaged signature looks like this
for ref:
[id(0x6002000d)]
BSTR E_a_testObj_obj _ref_att_dispat ch([in, out]
SAFEARRAY(IDisp atch*)* Value);
Both ByRef and ByVal worked.
Regards
/Niklas

"Nicholas Paldino [.NET/C# MVP]" wrote:
Niklas,

You should be able to declare it with the MarshalAs attribute, like
this:

void DoSomething([MarshalAs(Unman agedType.SafeAr ray,
SafeArraySubTyp e=VarType.VT_DI SPATCH)] ref object[] array)
{
// Do something with the array.
}

I'm not sure about the ref, you might need it for VB6 (you can try it
with and without).

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m

"Niklas" <Ni****@discuss ions.microsoft. com> wrote in message
news:85******** *************** ***********@mic rosoft.com...
Hi
I'm creating a .NET dll, which I will use in VB 6. I have no problem
declaring methods, which will take a single Object, String, Integer and so
on
as a parameter. I manage even to transfer arrays of Strings and integer,
but
I fail to pass an array of Objects in a parameter. How do I declare a
method,
where one of the parameters is an Object array, in .NET, which I will use
in
VB6?
Regards
/Niklas


Nov 16 '05 #3

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