ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH ACTIVEX
Creating a custom tool
Creating custom commands and tools to work with the MapControl and
PageLayoutControl is like creating commands for the ESRI ArcMap application
that you may have done previously. You will create a custom tool that adds a text
element containing today’s date to the PageLayoutControl at the location of a
mouse click. You will, however, create the command to work with the
MapControl and ToolbarControl as well as the PageLayoutControl.
The command class is implemented in a
separate ActiveX DLL project rather than inside
the ActiveX EXE project, because the command
will not become a COM class unless it is in a
DLL.
This scenario’s source code is located at
\DeveloperKit\samples\
Developer_Guide_Scenarios\Building_an_
ArcGIS_Controls_Map_Viewer_
ApplicationVisual_Basic.zip.
The code for this custom tool is available with the rest of this scenario’s source
code. If you want to use the custom command directly, rather than creating it
yourself, go directly to Step 12.
1. Start Visual Basic and create a new ActiveX DLL project from the New
project dialog box.
2. Name the project EngineScenarioCommands.
3. Click the Project menu again and click References.
4. In the References dialog box, check ESRI Carto Object Library, ESRI Control
Commands Object Library, ESRI Display Object Library, ESRI Geometry
Object Library, ESRI System Object Library, and ESRI SystemUI Object
Library. Click OK.
5. Add a class module to the project and name it AddDateTool.
6. Add in the ControlCommands.res Visual Basic resource file from its location in
this sample’s source code. To do this you will need the VB6 Resource Editor
add-in.
7. Add the following code to the general declarations area of the AddDateTool
class module.
Option Explicit
Implements ICommand
Implements ITool
Private m_pHookHelper As IHookHelper
Private m_pBitmap As IPictureDisp
8. Add the following code to the Class_Initialize and Class_Terminate methods.
Private Sub Class_Initialize()
' Load resources.
Set m_pBitmap = LoadResPicture("Date", vbResBitmap)
' Create a HookHelper.
Set m_pHookHelper = New HookHelper
End Sub
Private Sub Class_Terminate()
' Clear variables.
Set m_pHookHelper = Nothing
Set m_pBitmap = Nothing
End Sub
Chapter 6 • Developer scenarios • 295