asked on

convert a Variant (String Array) from VB 6 DLL to C#.NET String() array

Hi,

I have a VB6 DLL that passes a variant string array paramters to an event that is being call from my C#.net application. when i delegate the event in C# the parameters becomes object.

I need to convert this object into array of string in C#.NET
the code below doesnt work. It seems that i need to convert object array into string array
Can somegody please help me. ASAP please

private void AuthorizeComplete(object varOutput, bool bSuccess)
{
string x = varOutput(0,1);

}

Headspace

well, i'm a little confused, but i'll give it a shot : ).

if i were to assign a new string array to an existing string array, i'd do this:

string[] x = (string[])varOutput;

miggie_ra

ASKER

Hi,

Its giving an error of specified cast is not valid when i try that. the parameter is a variant string array coming from vb dll. but when i receive it to c#.net it converts it to and object system array type. and i cant iterate on that to retrieve values.

Headspace

ok, well, what if you assign varOutput to an object array, and then convert each object in the array to a string?

so something like:

string[] str;
object[] obj = varOutput;
for (int i = 0; (i <= obj.Length - 1); i++)
{
str[i] = (string)obj[i];
}

miggie_ra

ASKER

Hello,

its returning an error of 'Cannot implicitly convert type objec to object[] when i try this.

cheers.

Bob Learned

It might help if you marshal the array:

Default Marshaling for Arrays
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpcondefaultmarshalingforarrays.asp

<Quote>
...a safe array of variants becomes a managed array of objects. The SAFEARRAY element type is captured from the type library and saved in the SAFEARRAY value of the UnmanagedType enumeration...
</Quote>

Bob

Headspace

@bob: ...but doesn't that happen automatically? And if so, wouldn't:

object[] obj = (object[])varOutput;
string[] str = new string[obj.Length]; //sry, forgot to declare this string as new and assign a length to it in the previous ex.
for (int i = 0; (i <= obj.Length - 1); i++)
{
str[i] = (string)obj[i];
}

...work, theoretically speaking?

miggie_ra

ASKER

hi,

thanks for the infos, bob and headspace.
I agree it will work theoretically but I tried doing that already but and still giving me
'Cannot implicitly convert type objec to object[].

cheers

Bob Learned

If you are talking about this line:

private void AuthorizeComplete(object varOutput, bool bSuccess)

it would need to be:

private void AuthorizeComplete(object[] varOutput, bool bSuccess)

Marshalling variants is not automatic--marshalling string arrays is.

Bob

Headspace

oooooooooh! thx Bob : )

wil

miggie_ra

ASKER

i tried that already bob...
private void AuthorizeComplete(object[] varOutput, bool bSuccess)

is an event handler coming from vb.dll and i dont think i can change object varOutput into object[] varOutput...when i do that i get an error...

ASKER CERTIFIED SOLUTION

Bob Learned

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