How to create a command or tool to work with the controls

In this topic

• ArcGIS base command and base tool
• Creating a base command or base tool
• Using a base command or base tool in an application
  • Using the ArcGIS Engine ToolbarControl
  • Using the ArcGIS Engine controls without the ToolbarControl
  • Using an ArcGIS for Desktop application

ArcGIS base command and base tool

• The ArcGIS base command and base tool inherit from the BaseCommand and BaseTool abstract classes. Instead of implementing the Bitmap, Caption, Category, Name, Message, and ToolTip properties individually, you can set the values to be returned from these read-only properties in the class constructor and rely on the BaseCommand or BaseTool class to provide the implementation for these methods. The other members are left to return the default values as implemented by the BaseCommand or BaseTool class.

• ArcGIS Engine expects a custom command or tool to be a Component Object Model (COM) class. The ArcGIS base command and base tool provide the attributes and globally unique identifiers (GUIDs) required by COM in the class.
• Visual Studio provides the ability to specify functions that execute when an assembly exposed for COM is registered and unregistered on a system. This allows the class to be registered in a component category that a Customize dialog box looks for. The ArcGIS base command and base tool provide these COM component category registration functions.

Creating a base command or base tool

1. To add the ArcGIS base command or base tool to your Microsoft Visual Studio project, do one of the following:
   1. Select the project name in Solution Explorer and choose Add New Item from the Project menu.
   2. Right-click the project name in Solution Explorer, select Add, and click New Item (or press Ctrl+Shift+A).

The Add New Item dialog box opens. See the following screen shot:

2. Expand the ArcGIS node under Categories and click Extending ArcObjects.
3. Under Templates, select Base Command or Base Tool and click Add. The ArcGIS New Item Wizard Options dialog box opens.
4. Select the type of command or tool you want to create and click OK. The type of command or tool you choose depends on the ArcGIS Engine control or ArcGIS for Desktop application you want the command or tool to work with. See the following screen shots:
   
   

5. Add custom functionality to the command or tool. For example, provide Bitmap, Caption, Category, Name, Message, and ToolTip values for the command or tool in the class constructor. In the case of a command, provide implementation in the OnClick method. In the case of a tool, provide implementation in the OnMouseDown, OnMouseMove, or OnMouseUp methods.

Using a base command or base tool in an application

Using the ArcGIS Engine ToolbarControl

• Using the ToolbarControl property pages at design time.
• By the end user through the CustomizeDialog if the ToolbarControl is in Customize mode.
• Programmatically using the AddItem method.

Using the ArcGIS Engine controls without the ToolbarControl

1. Create an instance of the command or tool.
2. Pass the individual ArcGIS Engine control to the OnCreate method. When passing the control, use the Object property (for example, AxGlobeControl.Object when using the host wrapper) to ensure the real control is passed to the command or tool. This is done because .NET contains the real control inside a wrapper object or host.

//Create a command instance.
ICommand command=new myCommandClass();
//Pass the MapControl to the OnCreate method.
command.OnCreate(axMapControl1.Object);
//Call OnClick.
command.OnClick();

'Create a command instance.
Dim Command As ICommand=New myCommandClass()
'Pass the MapControl to the OnCreate method.
Command.OnCreate(AxMapControl1.Object)
'Call OnClick.
Command.OnClick()

//Create a tool instance.
ICommand command=new myToolClass();
//Pass the MapControl to the OnCreate method.
command.OnCreate(axMapControl1.Object);
//Set the MapControl's current tool.
axMapControl1.CurrentTool=command as ITool;

'Create a tool instance.
Dim Command As ICommand=New myToolClass()
'Pass the MapControl to the OnCreate method.
Command.OnCreate(AxMapControl1.Object)
'Set the MapControl's current tool.
AxMapControl1.CurrentTool=Command

5. The Enabled, Caption, and Bitmap properties of the command or tool can be read and incorporated into properties of a command button supplied by the development environment - for example, to build up the user interface of the application.

Using an ArcGIS for Desktop application

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