Interop on Marko Apfel

Interop effects by resolving and instantiating types with ArcObjects

Fri, 25 Nov 2011 14:10:00 +0100

Problem

this code does not work

Type t = typeof(ESRI.ArcGIS.Framework.AppRefClass);

System.Object obj = Activator.CreateInstance(t);

but yet this code

Type t = Type.GetTypeFromCLSID(typeof(ESRI.ArcGIS.Framework.AppRefClass).GUID);

System.Object obj = Activator.CreateInstance(t);

Reason

In the first variant the runtime tries to cast to AppRefClass . This is not possible.

"Failure has occurred while loading a type."

Fri, 28 Oct 2011 12:08:00 +0200

Motivation

During programming suddenly this error (“Failure has occurred while loading a type”) was thrown by accessing a artifact of a referenced library.

In such cases I take the assembly fusion logger fuslogvw to search for problems of loading assemblies. Sometimes an old version from a not expected folder is binded. But all bindings were correct.

Casing of COM-Interop registered components

Tue, 08 Jun 2010 09:54:00 +0200

During a refactoring i realized that renaming of components, which will be registered for COM-Interop, must be done carefully.

In my case i changed the casing of XyzToolbar to XyzToolBar.

At the developing machine everything works fine. But after installing the modified stuff at the production machine, the toolbar was not visible. Using regasm with the new assemblies helped.

Gefahren des “cleanup code refactoring” im Zusammenhang mit P/Invoke und übergebenen Strukturen

Wed, 28 Apr 2010 09:40:00 +0200

Problemkontext

So schön auch das automatische “cleanup code refactoring” von ReSharper ist, im Zusammenhang mit Strukturdefinitionen, die als Übergabe-Parameter für unmanaged Code Aufrufe benötigt werden, lauert eine große Gefahr.

Standardmäßig ist im Profil “Full Cleanup” die Option “Reorder type members” auf “Yes” gestellt.

Catching COM-Exceptions from ArcObjects

Tue, 20 Oct 2009 14:36:00 +0200

to catch the COM-Exception in own applications thrown from the underlaying ArcObjects-Library could be done with:

catch (COMException ComEx)



 Console.WriteLine(string.Format("MyCode errored: {0}, Error Code: {1}",



 ComEx.Message, ComEx.ErrorCode));

the special error constants could be found under: