Using the control commands

About using the control commands

Control commands with the ToolbarControl

• Through the ToolbarControl property pages at design time.
• Programmatically using the AddItem, AddMenuItem, and AddToolbarDef methods. The commands can be added to a ToolbarMenu using the AddItem and AddSubMenu methods, and the commands can be added to a ToolbarPalette using the AddItem method.
• By the end user if the ToolbarControl is in customize mode.

Control commands without the ToolbarControl

• A new instance of a command is created programmatically and the individual ArcGIS control is passed to the OnCreate event. For example, if the Zoom FullExtent command is to work with the MapControl, the MapControl must be passed as the hook to the OnCreate method.
• A developer can use the CommandPool object without the ToolbarControl to manage the commands used by an application. The CommandPool provides support for calling the OnCreate method of each command based on its Hook property.
• If the command implements only the ICommand interface, you can call the OnClick method at the appropriate time to perform the specific action. If the command is a tool that implements both the ICommand and ITool interfaces, set the tool to be the CurrentTool in the ArcGIS control. The ArcGIS control sends any keyboard and mouse events to the tool.
• A command's Enabled, Caption, and Bitmap properties can be read and set into the properties of a command button supplied by the development environment to build up the application's UI.

ICommand command = new ControlsSelectFeaturesToolClass();
command.OnCreate(axMapControl1.Object);
axMapControl1.CurrentTool = (ITool)command;

Dim pCommand As ICommand
pCommand = New ControlsSelectFeaturesToolClass
pCommand.OnCreate(AxMapControl1.Object)
AxMapControl1.CurrentTool = pCommand

Create custom commands

• The HookHelper object is used to hold on to the hook, and the IHookHelper interface it implements can return the ActiveView, PageLayout, and FocusMap properties, regardless of the type of hook that is passed.
• The GlobeHookHelper object is used to hold on to the hook, and the IGlobeHookHelper interface it implements can return the Camera, Globe, GlobeDisplay, and ActiveViewer properties, regardless of the type of hook that is passed.
• The SceneHookHelper object is used to hold on to the hook, and the ISceneHookHelper interface it implements can return the ActiveViewer, Scene, SceneGraph, and Camera properties, regardless of the type of hook that is passed.

public sealed class Command1: BaseCommand
{
    private IHookHelper m_pHookHelper;

    public override void OnCreate(object hook)
    {
        if (m_pHookHelper == null)
            m_pHookHelper = new HookHelperClass();
        m_pHookHelper.Hook = hook;
    }
}

Public NotInheritable Class Command1
Inherits BaseCommand

Private m_pHookHelper As IHookHelper

Public Overrides Sub OnCreate(ByVal hook As Object)
If (m_pHookHelper Is Nothing) Then m_pHookHelper = New HookHelperClass
m_pHookHelper.Hook = hook
End Sub

End Class

public override void OnClick()
{
    ESRI.ArcGIS.esriSystem.Array myArray = new ESRI.ArcGIS.esriSystem.Array();
    ISelection selection = m_pHookHelper.FocusMap.FeatureSelection;
    IEnumFeature enumFeature = (IEnumFeature)selection;
    IFeature feature;

    //Add the selected features' geometry to the array.
    enumFeature.Reset();
    feature = enumFeature.Next();
    do
    {
        myArray.Add(feature.Shape);
        feature = enumFeature.Next();
    }
    while (feature != null);

    //If zooming is supported, zoom to the selected features.
    IHookActions hookActions = (IHookActions)m_pHookHelper;
    if (hookActions.get_ActionSupportedOnMultiple(myArray,
        esriHookActions.esriHookActionsZoom) == true)
        hookActions.DoActionOnMultiple(myArray, esriHookActions.esriHookActionsZoom);
}

Public Overrides Sub OnClick()
Dim myArray As ESRI.ArcGIS.esriSystem.Array = New ESRI.ArcGIS.esriSystem.Array
Dim selection As ISelection = m_pHookHelper.FocusMap.FeatureSelection
Dim enumFeature As IEnumFeature = selection, feature As IFeature

'Add the selected features' geometry to the array.
enumFeature.Reset()
feature = enumFeature.Next
Do Until feature Is Nothing
    myArray.Add(feature.Shape)
    feature = enumFeature.Next
Loop

'If zooming is supported, zoom to the selected features.
Dim hookActions As IHookActions = m_pHookHelper
If (hookActions.ActionSupportedOnMultiple(myArray, esriHookActions.esriHookActionsZoom) = True) Then
    hookActions.DoActionOnMultiple(myArray, esriHookActions.esriHookActionsZoom)
End If
End Sub

Singleton objects

• The CommandsEnvironment object implements the IGraphicProperties and ILayerEffectProperties interfaces. The members of IGraphicProperties manage the default MarkerSymbol, LineSymbol, and FillSymbol properties used by the control commands.
• The EngineEditor object implements the IEngineEditProperties, IEngineEditProperties2, and IEngineSnapEnvironment interfaces. The members of these interfaces manage the properties of edit sessions and snap agents.
• The EngineInkEnvironment object implements the IEngineInkEnvironment and IEngineInkEnvironmentEvents interfaces. The members of these interfaces manage the ink collection and tablet properties.
• The EngineNetworkAnalystEnvironment object implements the IEngineNetworkAnalystEnvironment, IEngineNetworkAnalystEnvironmentEvents, and IEngineNetworkAnalystHelper interfaces. The members of these interfaces manage the collection of network layers and the current network layer by solving for current network locations and getting directions after solving.
• The MyPlaceCollection object implements the IEnumPlace and IPlaceCollection interfaces. The members of these interfaces manage the addition and removal of Place objects to the place collection.

See Also: