Building editor extensions using add-ins

Click here to get the sample associated with this walkthrough.

In this topic

• Editor extensions
• Creating a Visual Studio project
• Using the ArcGIS Add-Ins Wizard
• Understanding the XML
• Implementing run time behavior
• Installing the add-in
• Testing the editor extension
• Uninstalling the add-in

Editor extensions

Creating a Visual Studio project

6. Click OK to close the dialog box and open the ArcGIS Add-Ins Wizard.

Using the ArcGIS Add-Ins Wizard

4. Click Finish. An add-in project is created. The following screen shot shows the files created by the wizard as seen in Solution Explorer:
   
   

Understanding the XML

Implementing run time behavior

• The ValidateFeaturesExtension class must inherit the ESRI.ArcGIS.Desktop.AddIns.Extension class.
• The template code shows how to wire editor events. Static classes, such as ArcMap, are predefined in config.Designer.cs. The static ArcMap class has several static members—such as application, document, editor, and events—that you can use for your run time implementation. The following screen shot shows the ArcMap class and its static members:
  
  

//Invoked when the editor extension is loaded.
protected override void OnStartup()
{
    Events.OnStartEditing += new IEditEvents_OnStartEditingEventHandler
        (Events_OnStartEditing);
    Events.OnStopEditing += new IEditEvents_OnStopEditingEventHandler
        (Events_OnStopEditing);
}

//Invoked at the start of an editor session.
void Events_OnStartEditing()
{
    //Since features of shapefiles, coverages, and so on, cannot be validated, ignore wiring 
    //events for them.
    if (ArcMap.Editor.EditWorkspace.Type !=
        esriWorkspaceType.esriFileSystemWorkspace)
    {
        //Wire OnCreateFeature edit event.
        Events.OnCreateFeature += new IEditEvents_OnCreateFeatureEventHandler
            (Events_OnCreateChangeFeature);
        //Wire onChangeFeature edit event.
        Events.OnChangeFeature += new IEditEvents_OnChangeFeatureEventHandler
            (Events_OnCreateChangeFeature);
    }
}

//Invoked at the end of an editor session (Editor->Stop Editing).
void Events_OnStopEditing(bool Save)
{
    //Since features of shapefiles, coverages, and so on, cannot be validated, ignore wiring 
    //events for them.
    if (ArcMap.Editor.EditWorkspace.Type !=
        esriWorkspaceType.esriFileSystemWorkspace)
    {
        //Unwire OnCreateFeature edit event.
        Events.OnCreateFeature -= new IEditEvents_OnCreateFeatureEventHandler
            (Events_OnCreateChangeFeature);
        //Unwire onChangeFeature edit event.
        Events.OnChangeFeature -= new IEditEvents_OnChangeFeatureEventHandler
            (Events_OnCreateChangeFeature);
    }
}

//Invoked when a feature is created or modified.
void Events_OnCreateChangeFeature(ESRI.ArcGIS.Geodatabase.IObject obj)
{
    IFeature inFeature=(IFeature)obj;
    if (inFeature.Class is IValidation)
    {
        IValidate validate=(IValidate)inFeature;
        string errorMessage;
        //Validates connectivity rules, relationship rules, topology rules, and so on.
        bool bIsvalid=validate.Validate(out errorMessage);
        //Report validation result.
        if (!bIsvalid)
        {
            System.Windows.Forms.MessageBox.Show("Invalid Feature\n\n" +
                errorMessage);
        }
        else
        {
            System.Windows.Forms.MessageBox.Show("Valid Feature");
        }
    }
}

'Invoked when the editor extension is loaded.
Protected Overrides Sub OnStartup()
AddHandler Events.OnStartEditing, AddressOf Events_OnStartEditing
AddHandler Events.OnStopEditing, AddressOf Events_OnStopEditing
End Sub

'Invoked at the start of the editor session.

Private Sub Events_OnStartEditing()
    'Since features of shapefiles, coverages, and so on, cannot be validated, ignore wiring
    'events for them.
    If ArcMap.Editor.EditWorkspace.Type <> esriWorkspaceType.esriFileSystemWorkspace Then
        'Wire OnCreateFeature edit event.
        AddHandler Events.OnCreateFeature, AddressOf Events_OnCreateChangeFeature
        'Wire onChangeFeature edit event.
        AddHandler Events.OnChangeFeature, AddressOf Events_OnCreateChangeFeature
    End If
End Sub

'Invoked at the end of the edit session.

Private Sub Events_OnStopEditing(ByVal Save As Boolean)
    'Since features of shapefiles, coverages, and so on, cannot be validated, ignore wiring
    'events for them.
    If ArcMap.Editor.EditWorkspace.Type <> esriWorkspaceType.esriFileSystemWorkspace Then
        'Unwire OnCreateFeature edit event.
        RemoveHandler Events.OnCreateFeature, AddressOf Events_OnCreateChangeFeature
        'Unwire onChangeFeature edit event.
        RemoveHandler Events.OnChangeFeature, AddressOf Events_OnCreateChangeFeature
    End If
End Sub

'Invoked when a feature is created or modified.

Private Sub Events_OnCreateChangeFeature(ByVal obj As ESRI.ArcGIS.Geodatabase.IObject)
    Dim inFeature As IFeature=CType(obj, IFeature)
    If TypeOf inFeature.Class Is IValidation Then
        Dim validate As IValidate=CType(inFeature, IValidate)
        Dim errorMessage As String
        Dim bIsvalid As Boolean=validate.Validate(errorMessage)
        If (Not bIsvalid) Then
            System.Windows.Forms.MessageBox.Show("Invalid Feature" & Constants.vbLf + Constants.vbLf & errorMessage)
        Else
            System.Windows.Forms.MessageBox.Show("Valid Feature")
        End If
    End If
End Sub

Installing the add-in

1. Save the project.
2. In Visual Studio, click the Build menu, and click Build Solution.
3. View the output window in your Visual Studio .NET IDE. If the project builds correctly, the output shows that the build has succeeded and the add-in has been installed to the current user location.

Testing the editor extension

1. Start ArcMap, open a map document, and add data that has connectivity rules, relationship rules, or topology rules associated with it.
2. Click Customize and click Add-In Manager. The Add-In Manager dialog box appears. The Add-In Manager dialog box lists the add-ins that are currently installed for the application. Add-in information—such as name, image, and description—is listed on the Add-In Manager dialog box.  
3. Click Close.
4. Click Customize, click Toolbars, and click Editor.
5. Dock the Editor toolbar, click Editor, and click Start Editing.
6. Select a data feature and move it. This triggers the onChangeFeature event, and the feature is validated for the new location. A message box shows the validation result as shown in the following screen shot:
   
   

Uninstalling the add-in

1. In ArcMap, click Customize, and click Add-In Manager. The Add-In Manager dialog box appears.
2. Select AddInEditorExtension and click Uninstall Add-In. The corresponding add-in file is deleted from the user location where it was installed.

See Also: