ZoomIn

ZoomIn.cs

using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using System.Runtime.InteropServices;

namespace ZoomFactorExtensionCSharp
{
	[ClassInterface(ClassInterfaceType.None)]
	[Guid("745f7a73-ac7b-418d-a709-fb5b4cb179ae")]
	public sealed class ZoomIn: BaseCommand
	{
		//The HookHelper object that deals with the hook passed to the OnCreate event
		private IHookHelper m_HookHelper = new HookHelperClass();

		#region "Component Category Registration"
		[ComRegisterFunction()]
		static void Reg(string regKey)
		{
			ControlsCommands.Register(regKey);
		}

		[ComUnregisterFunction()]
		static void Unreg(string regKey)
		{
			ControlsCommands.Unregister(regKey);
		}
		#endregion

		public ZoomIn()
		{
			//Set the command properties			
			base.m_caption = "Variable Zoom In";
			base.m_message = "Variable Zoom In";
			base.m_toolTip = "Variable Zoom In";
			base.m_category = "ZoomExtension Sample(CSharp)";
			base.m_name = "ZoomExtension Sample(CSharp)_Variable Zoom In";
			base.m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream("Commands.zoominfxd.bmp"));
		}
	
		public override void OnCreate(object hook)
		{
			m_HookHelper.Hook = hook;
		}
		
		public override bool Enabled
		{
			get
			{
				//Get the extension manager
				IExtensionManager extensionManager = new ExtensionManagerClass();

				//Get the extension from the extension manager
				IExtension extension = extensionManager.FindExtension("Zoom Factor Extension");

				//Get the state of the extension
				IExtensionConfig extensionConfig = (IExtensionConfig) extension;
				if (extensionConfig != null)
				{
					if (extensionConfig.State == esriExtensionState.esriESEnabled) return true;
					else return false;
				}
				else
				{
					return false;
				}
			}
		}

		public override void OnClick()
		{
			//Get the current extent of the active view
			IActiveView activeView = m_HookHelper.ActiveView;
			IEnvelope envelope = activeView.Extent;

			//Get the extension manager
			ExtensionManager extensionManager = new ExtensionManagerClass();
			//Get the extension from the extension manager
			IExtension extension = extensionManager.FindExtension("Zoom Factor Extension");

			//Get the zoom factor from the extension
			double zoomFactor = 1.1;
			if (extension != null)
			{
				IZoomExtension zoomExtension = (IZoomExtension) extension;
				zoomFactor = zoomExtension.ZoomFactor;
			}
			else
			{
				System.Windows.Forms.MessageBox.Show("The extension cannot be found!");
			}

			//Update the current extent of the active view
			envelope.Expand((System.Convert.ToDouble(1.0)/ zoomFactor), (System.Convert.ToDouble(1.0) / zoomFactor), true);
			activeView.Extent = envelope;
			activeView.Refresh();
		}
	}
}

ZoomIn.vb

Option Explicit On 

Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.Geometry
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Controls
Imports ESRI.ArcGIS.ADF.BaseClasses
Imports ESRI.ArcGIS.ADF.CATIDs
Imports System.Runtime.InteropServices

<ComClass(ZoomIn.ClassId, ZoomIn.InterfaceId, ZoomIn.EventsId)> _
Public NotInheritable Class ZoomIn
    Inherits BaseCommand
    Private m_Hookhelper As IHookHelper

#Region "COM GUIDs"
    ' These  GUIDs provide the COM identity for this class 
    ' and its COM interfaces. If you change them, existing 
    ' clients will no longer be able to access the class.
    Public Const ClassId As String = "dfb082ac-6cd5-4a62-800d-ec8f75443172"
    Public Const InterfaceId As String = "7331345f-eb11-436a-a614-2eaf7462a1f3"
    Public Const EventsId As String = "19ae4591-45a0-410a-b3e7-de38463a20e2"
#End Region

#Region "Component Category Registration"
	<ComRegisterFunction()> _
	Public Shared Sub Reg(ByVal regKey As String)
		ControlsCommands.Register(regKey)
	End Sub

	<ComUnregisterFunction()> _
	Public Shared Sub Unreg(ByVal regKey As String)
		ControlsCommands.Unregister(regKey)
	End Sub
#End Region

    Public Sub New()
        MyBase.New()

        'Create an IHookHelper object
        m_Hookhelper = New HookHelperClass

        'Set the command properties
        MyBase.m_caption = "Variable Zoom In"
        MyBase.m_message = "Variable Zoom In"
        MyBase.m_toolTip = "Variable Zoom In"
        MyBase.m_category = "ZoomExtension Sample(VB.NET)"
        MyBase.m_name = "ZoomExtension Sample(VB.NET)_Variable Zoom In"
        MyBase.m_bitmap = New System.Drawing.Bitmap(GetType(ZoomIn).Assembly.GetManifestResourceStream(GetType(ZoomIn), "zoominfxd.bmp"))

    End Sub

    Public Overrides ReadOnly Property Enabled() As Boolean
        Get
            'Get the extension manager
            Dim pExtensionManager As IExtensionManager = New ExtensionManagerClass

            'Get the extension from the extension manager
            Dim pExtension As IExtension
            pExtension = pExtensionManager.FindExtension("Zoom Factor Extension")

            'Get the state of the extension
            Dim pExtensionConfig As IExtensionConfig
            pExtensionConfig = pExtension
            If (Not pExtensionConfig Is Nothing) Then
                If (pExtensionConfig.State = esriExtensionState.esriESEnabled) Then
                    Return True
                Else
                    Return False
                End If
            Else
                Return False
            End If
        End Get
    End Property

    Public Overrides Sub OnCreate(ByVal hook As Object)
        m_Hookhelper.Hook = hook
    End Sub

    Public Overrides Sub OnClick()
        'Get the current extent of the active view
        Dim pActiveView As IActiveView
        pActiveView = m_Hookhelper.ActiveView
        Dim pEnvelope As IEnvelope
        pEnvelope = pActiveView.Extent

        'Get the extension manager
        Dim pExtensionManager As ExtensionManager
        pExtensionManager = New ExtensionManagerClass
        'Get the extension from the extension manager
        Dim pExtension As IExtension
        pExtension = pExtensionManager.FindExtension("Zoom Factor Extension")

        'Get the zoom factor from the extension
        Dim ZoomFactor As Double
        ZoomFactor = 1.1
        Dim pZoomExtension As IZoomExtension
        If (Not pExtension Is Nothing) Then
            pZoomExtension = pExtension
            ZoomFactor = pZoomExtension.ZoomFactor
        Else
            System.Windows.Forms.MessageBox.Show("The extension cannot be found!")
        End If

        'Update the current extent of the active view
        pEnvelope.Expand((Convert.ToDouble(1.0) / ZoomFactor), (Convert.ToDouble(1.0) / ZoomFactor), True)
        pActiveView.Extent = pEnvelope
        pActiveView.Refresh()
    End Sub
End Class