ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH ACTIVEX
The ICommand_OnCreate event is passed a
handle or hook to the application that the
command will work with. In this case it can be a
MapControl, PageLayoutControl, or
ToolbarControl. Rather than adding code into
the OnCreate event to determine the type of
hook that is being passed to the command, you
will use the HookHelper to handle this. A
command or tool needs to know how to handle
the hook it gets passed, so a check is needed to
determine the type of ArcGIS Control that has
been passed. The HookHelper is used to hold the
hook and return the ActiveView regardless of the
type of hook (in this case a MapControl,
PageLayoutControl, or ToolbarControl).
Private Property Get ICommand_Tooltip() As String
ICommand_Tooltip = "Add date"
End Property
10. You now need to stub out all of the properties and events of the ITool interface,
even if you are not going to use some of these. Add the following code
to the ITool properties and methods:
Private Property Get ITool_Cursor() As esriSystem.OLE_HANDLE
' Not implemented
End Property
Private Function ITool_Deactivate() As Boolean
ITool_Deactivate = True
End Function
Private Function ITool_OnContextMenu(ByVal x As Long, ByVal y As Long) As
Boolean
' Not implemented
End Function
Private Sub ITool_OnDblClick()
' Not implemented
End Sub
Private Sub ITool_OnKeyDown(ByVal keyCode As Long, ByVal shift As Long)
' Not implemented
End Sub
Private Sub ITool_OnKeyUp(ByVal keyCode As Long, ByVal shift As Long)
' Not implemented
End Sub
Private Sub ITool_OnMouseDown(ByVal button As Long, ByVal shift As Long,
ByVal x As Long, ByVal y As Long)
' Get the active view.
Dim pActiveView As IActiveView
Set pActiveView = m_pHookHelper.ActiveView
' Create a new text element.
Dim pTextElement As ITextElement
Set pTextElement = New TextElement
' Create a text symbol.
Dim pTextSymbol As ITextSymbol
Set pTextSymbol = New TextSymbol
' Create a font.
Dim pFont As stdole.StdFont
Set pFont = New stdole.StdFont
pFont.Name = "Arial"
pFont.Bold = True
pFont.Size = 25
Chapter 6 • Developer scenarios • 297