ArcGIS Engine Developer Guide

.NET APPLICATION PROGRAMMING INTERFACE
make use of their functionality. For example, all ArcMap commands and tools
must be registered in the ESRI Mx Commands component category. There are a
few different ways you can register a .NET component in a particular category,
but before doing so, the .NET components must be registered with COM. See the
‘Registering .NET components with COM’ section above for details.
Customize dialog box
Custom .NET ArcGIS commands and tools can quickly be added to toolbars via
the Add From File button on the Customize dialog box. In this case, you simply
have to browse for the TLB and open it. The ArcGIS framework will automatically
add the classes you select in the type library to the appropriate component
category.
Categories utility
Another option is to use the Component Categories Manager (Categories.exe). In
this case you select the desired component category in the utility, browse for your
type library, and choose the appropriate class.
COM Register Function
The final and recommended solution is to add code to your .NET classes that will
automatically register them in a particular component category whenever the
component is registered with COM. The .NET Framework contains two attribute
classes (ComRegisterFunctionAttribute and ComUnregisterFunctionAttribute)
that allow you to specify methods that will be called whenever your component
is being registered or unregistered. Both methods are passed the CLSID of the
class currently being registered, and with this information you can write code
inside the methods to make the appropriate registry entries or deletions. Registering
a component in a component category requires that you also know the component
category’s unique ID (CATID).
The code excerpt below shows a custom ArcMap command that automatically
registers itself in the MxCommands component category whenever the .NET
assembly in which it resides is registered with COM.
public sealed class AngleAngleTool: BaseTool
{
[ComRegisterFunction()]
static void Reg(String regKey)
{
Microsoft.Win32.Registry.ClassesRoot.CreateSubKey(regKey.
Substring(18)+ "\\Implemented Categories\\" + "{B56A7C42-83D4-11D2-A2E9-
080009B6F22B}");
}
[ComUnregisterFunction()]
static void Unreg(String regKey)
{
Microsoft.Win32.Registry.ClassesRoot.DeleteSubKey(regKey.Substring(18)+
"\\Implemented Categories\\" + "{B56A7C42-83D4-11D2-A2E9-080009B6F22B}");
}
Chapter 4 • Developer environments • 167