VBA and ArcObjects

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VBA and ArcObjects

• Fall 2003
• Advanced GIS

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VBA

• Available in ArcMap, ArcCatalog, and ArcScene
  applications
• Many other programming languages can work with
  ArcObjects, such as VB,C
• VBA is the easiest one for interacting with
  ArcMap.

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ArcObjects

• There are 1,000 classes and 2,000 interfaces
  documented in several object model diagrams.
• With such extensive collection of classes, you
  can create many customized applications to extend
  ArcGISs functions.
• Where to begin with? is the major difficulties
  faced by GIS programmers.
• Problem solving strategy help you glide through
  the real-world ArcObjects programming tasks.
• Three parts of problem-solving guides

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I Define the ArcObjects Programming Tasks

• Describe the problem in ArcObjects terms
• Identify subtasks
• Decide where to write the code
• Search for a related sample of recommended
  methodology

5
II Locate the correct object model

• Identify a subtask
• Extract keywords
• Search for the correct object model diagrams
• Review all related documentation

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III Navigate the object model diagram

• Review the structure of the object model diagram
• Trace the flow between classes and assemble code

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Describe the problem in ArcGIS terms

• For example Add a dataset called States to
  ArcMap can be described as
• Access the States feature class from a personal
  geodatabase and add it to ArcMap.
• A two-step approach illustrate the procedures.

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Customize Toolbars

• Open a ArcMap screen (StartgtProgramsgtArcGISgtArcMap
  )
• Bring in your county themes by click on Add
  layers from toolbar and navigate to your folder
  and then add them to current project.
• You may also convert ArcView project to ArcMap
  (File gt Import from ArcView project..)
• Once your themes are in the project, practice the
  functions of ArcMap (such as right-click on layer
  to open command panel.)

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Showing/Hiding toolbars

• Double-click any unoccupied area of any toolbars
  to display the Customize dialog box (or from
  ToolsgtCustomize..)
• The presence of a check mark next to the toolbar
  name indicates it is present.
• In the Toolbars tab of the Customize dialog ,
  click New. In the Toola Name area type in My
  personal tools and Save in Normal.mxt
• Click OK

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Adding more tools to your personal tool box

• Adding buttons and menus to your personal tool by
  selecting commands dragging to My personal
  tools toolbar. With category of Menu open
  (CommandgtMenu), drag commands on right window to
  My personal tools
• Practice putting different menu and commands on
  your personal toolbar. You can also remove them
  by dragging out of the box.
• Click Close to close the customize window.

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Saving change to a template

• Go to File gt Save As and navigate to the
  installed folder (most probably e\arcgis81
  darcgis81 or c\arcgis81, or \arcexec80\)
• Move in template folder and create a new folder
  called newtemplate and save your file as test.mxt
  (ArcMap Template, .mxt)

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Writing Macros in VBA

• You can use VBA integrated development
  environment (IDE) to create macros to help you
  automate tasks you perform repeatedly
• With the VB Editor you can edit macros, copy
  macros from one module to next, rename modules
  that store macros.
• Click the Tool menu, point to Macros, then click
  Macro. In the Macro dialog, type MyZoomIn as name
  and click Creat (this will take you to the VB
  screen and you are ready to create a customized
  tool)

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Code window

• Sub MyZoomIn()
• '
• ' macro MyRoomIn
• '
• Dim pDoc As IMxDocument
• Dim pEnv As IEnvelope
• Set pDoc ThisDocument
• Set pEnv pDoc.ActiveView.Extent
• pEnv.Expand 0.5, 0.5, True
• pDoc.ActiveView.Extent pEnv
• pDoc.ActiveView.Refresh
• End Sub
• Envelopes are the rectangular window that contain
  a specific element.  All Geometry objects have an
  envelope defined by the XMin, XMax, YMin, and
  YMax of the object.  Envelopes can also serve as
  the viewing area for a particular view screen or
  data frame.

ArcMap Doc
ThisPredefined variable-is the Idocument
interface to the MxDocument object
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ThisDocument - predefined variable, is the
Idocument interface to the MxDocument object

• Sub MyZoomIn()
• '
• ' macro MyRoomIn
• '
• Dim pDoc As IMxDocument
• Dim pEnv As IEnvelope
• Set pDoc ThisDocument
• Set pEnv pDoc.ActiveView.Extent
• pEnv.Expand 0.5, 0.5, True
• pDoc.ActiveView.Extent pEnv
• pDoc.ActiveView.Refresh
• End Sub
• Envelopes are the rectangular window that contain
  a specific element.  All Geometry objects have an
  envelope defined by the XMin, XMax, YMin, and
  YMax of the object.  Envelopes can also serve as
  the viewing area for a particular view screen or
  data frame.

ArcMap Doc
ActiveView property provides an IActiveView
interface that links the document data to the
current screen display of that data
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Run Macro

• Go to FilegtClose Return to ArcMap
• In ArcMap, go to ToolsgtMacrogt and select
  Module1.MyZoomIn macro and click Run (make sure
  your macro settings is in Normal)
• The display zoomed in 50 smaller.

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Add Macro to a toolbar

• Go to Tools gt Customize.
• In the Toolbar tab, make sure My personal Tool
  is still there (created previously on slide 5)
• Click Command tab and select Macros category.
  Select your macro (MyRoomIn) and drag to My
  Personal Tool bar
• A default icon appears. To change image,
  right-click on this icon and a context menu
  shows, go to Change Button Image and select one
  from the panel (smiling face,ok?)
• Close the Customize dialog box
• Click the smiling face to run the macro

Right-click on smiling face, select View Source
to modify your code to 0.75 from 0.5 for zoomin
ratio
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Exercise

• Create a new Macro named MyRoomOut in Module1
• Hint copy code from codewindow (from the
  beginning of the Sub to the End Sub, and paste
  below the existing code. Rename the copied Sub
  to MyZoomOut and change line
• pEnv.Expand 0.5, 0.5, True to
• pEnv.Expand 2.0,2.0,True
• Add this macro to My Personal Tool and run it

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Calling built-in commands

• Calling existing commands is working with the
  ArcID module. Using Find methods, the code
  locates the unique identifier (UID) of the
  command in the ArcID module (in normal template)
• Go to ToolsgtMacrosgtVisual Basic Editor
• In the Module 1 module, create a Sub procedure
  with the code such as the following page
• Add this macro to your tool bar and run it.

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Sub FullExtentPlus()

• Sub FullExtentPlus()
• '
• ' mcaro FullExtentPlus
• '
• Dim intAns As Integer
• Dim pItem As ICommandItem
• With ThisDocument.CommandBars
• Set pItem .Find(ArcID.PanZoom_FullExtent)
• pItem.Execute
• intAns MsgBox("Zoom to previous extent?",
  vbYesNo)
• If intAns vbYes Then
• Set pItem .Find(ArcID.PanZoom_ZoomToLas
  tExtentBack)
• pItem.Execute
• End If
• End With
• End Su

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Commands in VBA

• Command, similar to macro but, allow more
  customization in the way that it interacts with
  the user and provides ToolTips, description, and
  so on.
• A command is a type of UIControls(Application-gtDoc
  ument-gtCommand Bars-gtCommandBar-gtCommand
  Item-gtCommand-gtUIControl-gtUIButton
  Control,UIComboBoxControl,UIEditBoxControl,UIToolC
  ontrol,

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Create Command

• Go to ToolsgtCustomize and in Save in(at the
  bottom of the dialog) change to Untitled
• In the Categories list, select UIControls and
  click on New UIControl
• In the dialog box, choose UIButtonControl as
  UIControl type, then click Create and Edit

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Adding code for UIToolControl

• Now you have an Object UIButtonControl and a
  subprocedure for UIButtonControl_Click() event.
  You need to add code to this event to zoom the
  display to the extents of the dataset. Add the
  following code to the Click event. So far you
  have done exactly same procedures as macro. Next,
  you will add a ToolTip and message for the
  command.

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Message in command

• Scroll event from Click to Message, this create a
  stub function for this command.
• Add code to this function
• Scroll to ToolTip and type in code as follows
• UIButtonControl1_ToolTip Full Extent
• Close -gtReturn to ArcMap

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Test this command

• Back to ArcMap
• Go to ToolsgtCustomizegt and click Command tab
  and change Save in to Untitled
• Drag Project.UIButtonControl to toolbar to
  create your own tool.
• Test this button and move cursor over the button.
  The ToolTip will appear and at the bottom of the
  window the status bar will display the
  description of this button

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Exercise Create a tool through UIToolControl

• Same procedures as creating UIButtonControl
  except selecting UIToolControl and click
  Create and Edit
• This tool will deal with Select event. Go to
  MouseDown event in the Procedures comboBox on
  the right-side of the Code Window and add the
  following code to this event
• Dim pDoc As IMxDocument
• Dim pScreenDisp As IScreenDisplay
• Dim pRubber As IRubberBand
• Dim pEnv As IEnvelope
• Set pDoc ThisDocument
• Set pScreenDisp pDoc.ActiveView.ScreenDisplay
• Set pRubber New RubberEnvelope
• Set pEnv pRubber.TrackNew(pScreenDisp, Nothing)
• pDoc.ActiveView.Extent pEnv
• pDoc.ActiveView.Refresh

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Exercise - continued

• Add the following code to the UIToolControl1_Enabl
  ed() event procedure
• Dim pDoc As IMxDocument
• Set pDoc ThisDocument
• UIToolControl_Enabled (pDoc.FocusMap.LayerCou
  nt ltgt 0)
• Add the following code to the UIToolControl1_Curso
  rID() event procedure
• UIToolControl1_CursorID 3 'Crosshair
• Add ToolTip as described before for this tool
• Create this tool and test out the tool by
  selecting it and dragging a rectangle on the
  display