AutoCAD always starts up with a new or existing document open. It is possible, however, to close all documents during the current session.
If you close all the documents in the AutoCAD user interface, you will notice a few changes to the application window. The Quick Access toolbar and application menu offer limited options. These limited options are related to creating and opening drawings, displaying the Sheet Set Manager, and recovering drawings. If the menu bar is displayed, simplified File, View, Window, and Help menus are also displayed. You will also notice that there is no command line.
When working in zero document state, you can do the following:
To react to AutoCAD when it enters zero document state, you should use the DocumentDestroyed event. The DocumentDestroyed event is triggered when an open document is closed. The document count when the last document is closed will be 1. Use the Count property of the DocumentManager to determine the number of open documents at the time the DocumentDestroyed event is triggered.
For more information on the using events in AutoCAD, see Use Events.
Customize the application menu
This example code uses the DocumentDestroyed event to monitor when the last drawing is closed and when zero document state is entered. Once zero document state is entered, the Opening event is registered with the application menu. When the application menu is clicked, the Opening event is triggered. During the Opening event, a new menu item is added to the application menu. The new menu item displays a message box.
Imports System.Windows.Input
Imports Autodesk.Windows
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
'' Create the command handler for the custom application menu item
Public Class MyCommandHandler
Implements ICommand
Event CanExecuteChanged(ByVal sender As Object, ByVal e As EventArgs) _
Implements ICommand.CanExecuteChanged
Function CanExecute(ByVal parameter As Object) As Boolean _
Implements ICommand.CanExecute
Return True
End Function
Sub Execute(ByVal parameter As Object) Implements ICommand.Execute
Application.ShowAlertDialog("MyMenuItem has been clicked")End Sub
End Class
Public Class Chapter4
''Global var for ZeroDocState
Dim acApMenuItem As ApplicationMenuItem = Nothing
<CommandMethod("AddZeroDocEvent")> _Public Sub AddZeroDocEvent()
'' Get the DocumentCollection and register the DocumentDestroyed event
Dim acDocMgr As DocumentCollection = Application.DocumentManager
AddHandler acDocMgr.DocumentDestroyed, AddressOf docDestroyed
End Sub
Public Sub docDestroyed(ByVal obj As Object, _
ByVal acDocDesEvtArgs As DocumentDestroyedEventArgs)
'' Determine if the menu item already exists and the number of documents open
If Application.DocumentManager.Count = 1 And IsNothing(acApMenuItem) Then
'' Add the event handler to watch for when the application menu is opened
'' AdWindows.dll must be referenced to the project
AddHandler ComponentManager.ApplicationMenu.Opening, _
AddressOf ApplicationMenu_Opening
End If
End Sub
Public Sub ApplicationMenu_Opening(ByVal sender As Object, _
ByVal e As EventArgs)
'' Check to see if the custom menu item was added previously
If IsNothing(acApMenuItem) Then
'' Get the application menu component
Dim acApMenu As ApplicationMenu = ComponentManager.ApplicationMenu
'' Create a new application menu item
acApMenuItem = New ApplicationMenuItem()
acApMenuItem.Text = "MyMenuItem"
acApMenuItem.CommandHandler = New MyCommandHandler()
'' Append the new menu item
acApMenu.MenuContent.Items.Add(acApMenuItem)
'' Remove the application menu Opening event handler
RemoveHandler ComponentManager.ApplicationMenu.Opening, _
AddressOf ApplicationMenu_Opening
End If
End Sub
End Class
using Autodesk.Windows;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
// Create the command handler for the custom application menu item
public class MyCommandHandler : System.Windows.Input.ICommand
{public bool CanExecute(object parameter)
{return true;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{ Application.ShowAlertDialog("MyMenuItem has been clicked");}
}
class Chapter4
{//Global var for ZeroDocState
ApplicationMenuItem acApMenuItem = null;
[CommandMethod("AddZeroDocEvent")]public void AddZeroDocEvent()
{// Get the DocumentCollection and register the DocumentDestroyed event
DocumentCollection acDocMgr = Application.DocumentManager;
acDocMgr.DocumentDestroyed +=
new DocumentDestroyedEventHandler(docDestroyed);
}
public void docDestroyed(object obj,
DocumentDestroyedEventArgs acDocDesEvtArgs)
{// Determine if the menu item already exists and the number of documents open
if (Application.DocumentManager.Count == 1 && acApMenuItem == null)
{// Add the event handler to watch for when the application menu is opened
// AdWindows.dll must be referenced to the project
ComponentManager.ApplicationMenu.Opening +=
new EventHandler<EventArgs>(ApplicationMenu_Opening);
}
}
void ApplicationMenu_Opening(object sender, EventArgs e)
{// Check to see if the custom menu item was added previously
if (acApMenuItem == null)
{// Get the application menu component
ApplicationMenu acApMenu = ComponentManager.ApplicationMenu;
// Create a new application menu item
acApMenuItem = new ApplicationMenuItem();
acApMenuItem.Text = "MyMenuItem";
acApMenuItem.CommandHandler = new MyCommandHandler();
// Append the new menu item
acApMenu.MenuContent.Items.Add(acApMenuItem);
// Remove the application menu Opening event handler
ComponentManager.ApplicationMenu.Opening -=
new EventHandler<EventArgs>(ApplicationMenu_Opening);
}
}
}