How to call COM object function from classic ASP

Question

In my classic ASP site I need to call COM object function.

Here is the COM component definition:

interface IMyComponent : IDispatch
{ 
   HRESULT GetVersion([in] int, [out] double*, [out] BSTR*);
}

In server side I create component object and try to call 'GetVersion' function:

<%
    Dim app
    Set app = CreateObject("MyComponent")

    Dim someUsefulValue
    Dim version

    app.GetVersion 1, someUsefulValue, version
%>

But this code fails with error "Type mismatch". How I should call this function?

Can you explain what you are trying to achieve by this? I guess this is an in-browser app, so this seems very strange. I"d also be interested in knowing where you read about "JScript" :) — jrharshath
– jrharshath, Commented Jul 6, 2011 at 8:20
@jrharshath, I think he's talking about consuming COM objects from classic ASP, which leaves you either VBScript or JScript as your choices for language. — DuckMaestro
– DuckMaestro, Commented Jul 6, 2011 at 8:23
@Duck oh. owhhhhhhhhh... In that case, let me say upfront that it does not matter whether you're using ASP or not - what you are trying to do is access COM components on the client side, which immediately limits you to using on IE as the working browser. If that is acceptable to you, then feel free to continue on this treacherous path, but tread carefully :) — jrharshath
– jrharshath, Commented Jul 6, 2011 at 9:26

balexandre · Accepted Answer · 2011-07-06 08:30:07Z

1

first of all, keep in mind that no other browser supports ActiveX rather than Internet Explorer, so I would re-think if you shouldn't get other approach to the problem, maybe using other component that is more open to other browsers...

like Microsoft Silverlight (if you are going the .NET way), Adobe Flash, Shockwave, Air...

in HTML

Your ASP page needs to have the <object> code of your ActiveX

<OBJECT ID="myActiveX "
    CLASSID="clsid: yourControlId">
</OBJECT>

then you just act as a normal DOM object

var myActiveX = document.getElementById("myObject");
alert( myActiveX.GetVersion(...) );

answered Jul 6, 2011 at 8:30

balexandre

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3 Comments

Gabriele Petrioli Over a year ago

he is talking about ASP.. it is server-side..

jrharshath Over a year ago

I think he's talking about "JScript" -> definitely client-side.

maxvasil Over a year ago

I'm talking about serverside. @jrharshath, JScript can be used as server-side ASP language.

Jörgen Sigvardsson · Accepted Answer · 2011-07-06 09:12:30Z

0

Change the type of first parameter of the COM method to long, rather than int. Long translates to the variant type VT_I4, while int translates to VT_INT. If memory serves me right, VBScript doesn't recognize VT_INT as it's not an "automation compatible type" (the size of int may not be fixed across compilers/platforms!)

answered Jul 6, 2011 at 9:12

Jörgen Sigvardsson

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Comments

ThatGuyInIT · Accepted Answer · 2011-07-07 12:04:49Z

0

Try:

<%
    Dim app
    Set app = Server.CreateObject("MyComponent")

    Dim someUsefulValue
    Dim version

    app.GetVersion 1, someUsefulValue, version
%>

On the server side you should use Server.CreateObject, not just CreateObject as it is normally used for client side VBScript.

Make sure the COM object has been installed and registered using regsvr32 MyComponent.dll

edited Jul 7, 2011 at 12:04

answered Jul 6, 2011 at 17:47

ThatGuyInIT

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2 Comments

Cheran Shunmugavel Over a year ago

-1, CreateObject works, though Server.CreateObject is preferred.

ThatGuyInIT Over a year ago

@Cheran rephrased answer to say should instead of need

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