ArcObjects Library Reference  

SetZoomFactor

About the Creating a zoom factor extension that works with a ToolbarControl Sample

[C#]

SetZoomFactor.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;
using System.Windows.Forms;

namespace ZoomFactorExtensionCSharp
{
	[ClassInterface(ClassInterfaceType.None)]
	[Guid("e9ea3574-e45f-4197-9e07-9c0c323f8791")]
	public sealed class SetZoomFactor: 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 SetZoomFactor()
		{
			//Set the command properties			
			base.m_caption = "Set Variable Zoom";
			base.m_message = "Set Variable Zoom";
			base.m_toolTip = "Set Variable Zoom";
			base.m_category = "ZoomExtension Sample(CSharp)";
			base.m_name = "ZoomExtension Sample(CSharp)_Set Variable Zoom";
			base.m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream("Commands.zoomfactor.bmp"));
		}
	
		public override void OnCreate(object hook)
		{
			//Not implemented
		}
		
		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 extension manager
			ExtensionManager extensionManager = new ExtensionManagerClass();
			//Get the extension from the extension manager
			IExtension extension = extensionManager.FindExtension("Zoom Factor Extension");

			IZoomExtension zoomExtension = (IZoomExtension) extension;
			double zoomFactor = zoomExtension.ZoomFactor;

			//Get a zoom factor from the user
			InputFormResult res = InputForm.ShowModal(null,"Enter a zoom factor","ZoomExtension Sample", zoomExtension.ZoomFactor.ToString() );

			if (res.Result == DialogResult.Cancel) return;
			string zoomString = res.InputString;
			if (zoomString.Trim() == "") return;

			//Set the zoom factor
			if (System.Char.IsNumber(zoomString,0) == true) zoomExtension.ZoomFactor = System.Convert.ToDouble(zoomString);
		}
	}
}
[Visual Basic .NET]

SetZoomFactor.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(SetZoomFactor.ClassId, SetZoomFactor.InterfaceId, SetZoomFactor.EventsId)> _
Public NotInheritable Class SetZoomFactor
    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 = "0f65b096-8d64-4f03-a69d-0f976c32e6cf"
    Public Const InterfaceId As String = "83de6bce-2cf7-46e6-af2c-e396a694a34c"
    Public Const EventsId As String = "d1125967-20bc-4e55-9fdd-de5d831637f3"
#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 = "Set Variable Zoom"
        MyBase.m_message = "Set Variable Zoom"
        MyBase.m_toolTip = "Set Variable Zoom"
        MyBase.m_category = "ZoomExtension Sample(VB.NET)"
        MyBase.m_name = "ZoomExtension Sample(VB.NET)_Set Variable Zoom"
        MyBase.m_bitmap = New System.Drawing.Bitmap(GetType(ZoomOut).Assembly.GetManifestResourceStream(GetType(ZoomOut), "zoomfactor.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 OnClick()

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

        'Get the zoom extension interface
        Dim pZoomExtension As IZoomExtension
        pZoomExtension = pExtension

        'Get a zoom factor from the user
        Dim zoomString As String
        zoomString = InputBox("Enter Zoom Factor", "ZoomExtension Sample", CStr(pZoomExtension.ZoomFactor))

        'Set the zoom factor
        If IsNumeric(zoomString) Then pZoomExtension.ZoomFactor = CDbl(zoomString)

    End Sub

    Public Overrides Sub OnCreate(ByVal hook As Object)
        'Not implemented
    End Sub
End Class