Hi there,
I've got the following problem:
I am trying to build a simple application with VS 2005 and MapPoint 2004. I have read an article (http://www.mp2kmag.com/a103--chandu.thota.net.framework.mappoint.html) and tried the given example. It didn't work...
So I tried to build the code line by line:

Code:

 
 
using MapPoint;
/* ... */
public void makeMap()
{
ApplicationClass app = null;
app = new ApplicationClass();
app.Visible = true;
/* ... */
}

At line four I get an InvalidCastException (InvalidCastException: Unable to cast COM object of type "MapPoint.ApplicationClass" to interface type "MapPoint._Application") (the message may vary, though I translated it from German). Even before this line is executed, the debugger gives me the information, that the object app has InvalidCastExceptions on all variables...
I must add, that the code I tried here, was originally developed for VS .NET. Could that be the problem?
Maybe someone can help me, I'm looking forward to.
Thanks
Christian

PS: The original error message is: InvalidCastException was unhandled
Das COM-Objekt des Typs "MapPoint.ApplicationClass" kann nicht in den Schnittstellentyp "MapPoint._Application" umgewandelt werden. Dieser Vorgang konnte nicht durchgeführt werden, da der QueryInterface-Aufruf an die COM-Komponente für die Schnittstelle mit der IID "{D6D389CE-1781-47A0-8984-4349687F65D6}" aufgrund des folgenden Fehlers nicht durchgeführt werden konnte: Schnittstelle nicht unterstützt (Ausnahme von HRESULT: 0x80004002 (E_NOINTERFACE)).

PPS: Why is the forum search engine finding zero mathches for "C#"?

You're simply using the wrong interfaces for your intent.
I assume you've added a reference to the MPNA82.TLB file in your project.

Note: It is good practice to fully-qualify your references to avoid typecast errors.



public partial class Form1 : Form
{
private MapPoint.Application oMPApp;
private MapPoint.Map oMap;
......

private void makeMap()
{
oMPApp=new MapPoint.Application();
oMPApp.UserControl = true;
oMPApp.Visible = true;
oMap = oMPApp.ActiveMap;
}
.......


HTH
Paul

Hi Paul,
thanks for your reply, but this does not seem to be the solution for my problem.
Well I didn't add the MPEU82.TLB till now, but have had a reference to the COM-interface.

I tried your code snippet, but I still get this error message
Well thnk you anyway for your help

Christian

If you like, zip up your project and email it to me:
plarsonpma(at)hotmail(dot)com

I'll review it and send it back corrected.
If nothing's wrong with your project, then it would point to a bad installation or registry of MapPoint itself.

-Paul

Hi there,
the problem was, that MapPoint 2004 hasn't been installed properly. A simple repair of the installation ended my problem.
This might have occured, because I have had installed a MapPoint 2006 Trial temporarily.
Many Thanks to Paul

Christian

Hi,

thanks for feedback.
If you have more versions of mappoint you have to be sure to register the one for whitch you want to compile. you can do that from command interpreter: mappoint.exe /registerserver