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JDowner · Guest

Using D7 I have written a very simple in-process server COM object (with
Type lib) with one function and no properties that retruns shipment tracking
information. I am able to import the type library into D7 and use it in an
application.

The dll is to be used by a vendor that is writing a new web site for us in
..net. When they try to call the function they receive an error. Any ideas?

Here is their code and the error:

CHPComLib.ChpShipTrackClass chpTracker = new
CHPComLib.ChpShipTrackClass();
string status;
int len;
int result;
result = chpTracker.Track(txtCarrierCode.Text, txtTrackingNumber.Text,
out status, out len);
lblStatus.Text = status;
lblLength.Text = len.ToString();

txtCarrierCode.Text and txtTrackingNumber.Text are just pulling text strings
from a couple of text boxes I set up on a form. I'm getting the following
error when I execute the line that calls chpTracker.Track():

QueryInterface for interface CHPComLib.IChpShipTrack failed.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.InvalidCastException: QueryInterface for interface
CHPComLib.IChpShipTrack failed.

JDowner · Guest

Additional Info:

They registered my dll and added a reference to it in the ASP.NET web site
project. (When they add the reference, Visual Studio.NET automatically
creates an interop assembly - a .NET component which they can call from
ASP.NET and which calls the underlying COM component for them, handling all
of the marshalling of data, etc.) They then wrote a simple test page to
instantiate a ChpShipTrack object and call the Track() method.