ArcObjects Library Reference  

GoBackToPreviousExtent

About the Custom map navigation commands Sample

[C#]

GoBackToPreviousExtent.cs

using System;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.SystemUI;
using ESRI.ArcGIS.ADF.CATIDs;
using System.Runtime.InteropServices;

namespace PanZoom
{
	[ClassInterface(ClassInterfaceType.None)]
	[Guid("41631605-6B69-4778-8907-B161B24D98AF")]

	public class GoBackToPreviousExtent : ICommand
	{
        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

		[DllImport("gdi32.dll")]
		static extern bool DeleteObject(IntPtr hObject);

		private bool m_enabled;
		private System.Drawing.Bitmap m_bitmap;
		private IntPtr m_hBitmap;
		private IHookHelper m_pHookHelper;

		public GoBackToPreviousExtent()
		{
			string[] res = GetType().Assembly.GetManifestResourceNames();
			if(res.GetLength(0) > 0)
			{
				m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream(GetType(), "UnDoDraw.bmp"));
				if(m_bitmap != null)
				{
					m_bitmap.MakeTransparent(m_bitmap.GetPixel(1,1));
					m_hBitmap = m_bitmap.GetHbitmap();
				}
			}
			m_pHookHelper = new HookHelperClass ();
		}

		~GoBackToPreviousExtent()
		{
			if(m_hBitmap.ToInt32() != 0)
				DeleteObject(m_hBitmap);
		}
	
		#region ICommand Members

		public void OnClick()
		{
			//Get the active view
			IActiveView pActiveView = (IActiveView) m_pHookHelper.FocusMap;

			//Get the extent stack
			IExtentStack pMapExtent = (IExtentStack) pActiveView.ExtentStack;

			//Undo the extent view	
			if (pMapExtent.CanUndo())
			{
				pMapExtent.Undo();
			}
		}

		public string Message
		{
			get
			{
				return "Go to Previous Screen location";
			}
		}

		public int Bitmap
		{
			get
			{
				return m_hBitmap.ToInt32();
			}
		}

		public void OnCreate(object hook)
		{
			m_pHookHelper.Hook = hook;
		}

		public string Caption
		{
			get
			{
				return "Undo Extent";
			}
		}

		public string Tooltip
		{
			get
			{
				return "Undo Previous Extent";
			}
		}

		public int HelpContextID
		{
			get
			{
				// TODO:  Add GoBackToPreviousExtent.HelpContextID getter implementation
				return 0;
			}
		}

		public string Name
		{
			get
			{
				return "Sample_Pan/Zoom_Undo Extent";
			}
		}

		public bool Checked
		{
			get
			{
				return false;
			}
		}

		public bool Enabled
		{
			get
			{
				if (m_pHookHelper.FocusMap != null)
				{
					//Get the active view
					IActiveView pActiveView = (IActiveView) m_pHookHelper.FocusMap;

					//Get the extent stack
					IExtentStack pMapStack = (IExtentStack) pActiveView.ExtentStack;
					
					//Can the extent be undone

					return m_enabled = pMapStack.CanUndo();
				}
				return false;
			}
		}

		public string HelpFile
		{
			get
			{
				// TODO:  Add GoBackToPreviousExtent.HelpFile getter implementation
				return null;
			}
		}

		public string Category
		{
			get
			{
				return "Sample_Pan/Zoom";
			}
		}

		#endregion
	}
}

[Visual Basic .NET]

GoBackToPreviousExtent.vb

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

<ComClass(GoBackToPreviousExtent.ClassId, GoBackToPreviousExtent.InterfaceId, GoBackToPreviousExtent.EventsId)> _
Public NotInheritable Class GoBackToPreviousExtent
    Inherits BaseCommand

#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 = "26D27BF0-934C-49CF-8083-96AEC30AC114"
    Public Const InterfaceId As String = "DE5352BB-55B5-4028-9745-6018697A53A9"
    Public Const EventsId As String = "6B6DDA8C-D0D5-421F-BE06-F92C3A5138CB"
#End Region
#Region "COM Registration Function(s)"
    <ComRegisterFunction(), ComVisibleAttribute(False)> _
    Public Shared Sub RegisterFunction(ByVal registerType As Type)
        ' Required for ArcGIS Component Category Registrar support
        ArcGISCategoryRegistration(registerType)

        'Add any COM registration code after the ArcGISCategoryRegistration() call

    End Sub

    <ComUnregisterFunction(), ComVisibleAttribute(False)> _
    Public Shared Sub UnregisterFunction(ByVal registerType As Type)
        ' Required for ArcGIS Component Category Registrar support
        ArcGISCategoryUnregistration(registerType)

        'Add any COM unregistration code after the ArcGISCategoryUnregistration() call

    End Sub

#Region "ArcGIS Component Category Registrar generated code"
    ''' <summary>
    ''' Required method for ArcGIS Component Category registration -
    ''' Do not modify the contents of this method with the code editor.
    ''' </summary>
    Private Shared Sub ArcGISCategoryRegistration(ByVal registerType As Type)
        Dim regKey As String = String.Format("HKEY_CLASSES_ROOT\CLSID\{{{0}}}", registerType.GUID)
        ControlsCommands.Register(regKey)

    End Sub
    ''' <summary>
    ''' Required method for ArcGIS Component Category unregistration -
    ''' Do not modify the contents of this method with the code editor.
    ''' </summary>
    Private Shared Sub ArcGISCategoryUnregistration(ByVal registerType As Type)
        Dim regKey As String = String.Format("HKEY_CLASSES_ROOT\CLSID\{{{0}}}", registerType.GUID)
        ControlsCommands.Unregister(regKey)

    End Sub

#End Region
#End Region

    Private m_pEnabled As Boolean
    Private m_pHookHelper As IHookHelper

    ' A creatable COM class must have a Public Sub New() 
    ' with no parameters, otherwise, the class will not be 
    ' registered in the COM registry and cannot be created 
    ' via CreateObject.
    Public Sub New()
        MyBase.New()

        MyBase.m_category = "Sample_Pan_VBNET/Zoom"
        MyBase.m_caption = "Undo Extent"
        MyBase.m_message = "Go to Previous Screen location"
        MyBase.m_toolTip = "Draw Previous Extent"
        MyBase.m_name = "Sample_Pan/Zoom_Undo Extent"

        Dim res() As String = GetType(GoBackToPreviousExtent).Assembly.GetManifestResourceNames()
        If res.GetLength(0) > 0 Then
            MyBase.m_bitmap = New System.Drawing.Bitmap(GetType(GoBackToPreviousExtent).Assembly.GetManifestResourceStream("PanZoomVBNET.UnDoDraw.bmp"))
        End If
        m_pHookHelper = New HookHelperClass
    End Sub

    Public Overrides Sub OnClick()
        'Get the active view
        Dim pActiveView As IActiveView = CType(m_pHookHelper.FocusMap, IActiveView)

        'Get the extent stack
        Dim pMapExtent As IExtentStack = CType(pActiveView.ExtentStack, IExtentStack)

        'Undo the extent view	
        If pMapExtent.CanUndo() Then
            pMapExtent.Undo()
        End If
    End Sub

    Public Overrides Sub OnCreate(ByVal hook As Object)

        m_pHookHelper.Hook = hook
        m_pEnabled = True

    End Sub

    Public Overrides ReadOnly Property Enabled() As Boolean
        Get
            If m_pHookHelper.FocusMap Is Nothing Then Exit Property

            'Get the active view
            Dim pActiveView As IActiveView = CType(m_pHookHelper.FocusMap, IActiveView)

            'Get the extent stack
            Dim pMapStack As IExtentStack = CType(pActiveView.ExtentStack, IExtentStack)

            'Can the extent be undone
            Return m_pEnabled = pMapStack.CanUndo()
        End Get
    End Property
End Class