DesignerTransaction Klasse

Definition

public ref class DesignerTransaction abstract : IDisposable

public abstract class DesignerTransaction : IDisposable

type DesignerTransaction = class
    interface IDisposable

Public MustInherit Class DesignerTransaction
Implements IDisposable

Vererbung

Object

DesignerTransaction

Implementiert

IDisposable

Beispiele

Das folgende Codebeispielprogramm veranschaulicht, wie ein Designer erstellt DesignerTransaction wird. Um dieses Beispiel auszuführen, kompilieren Sie den Quellcode in eine Klassenbibliothek. Sie müssen einen Verweis auf die System.Design-Assembly hinzufügen. Fügen Sie in einem neuen Projekt einen Verweis auf die kompilierte DLL hinzu, und fügen Sie die Komponente in der Bibliothek der Toolbox hinzu.

Dieses Feature wird in Visual Studio umfassend unterstützt.

Siehe auch Exemplarische Vorgehensweise: Automatisches Auffüllen der Toolbox mit benutzerdefinierten Komponenten.

Der Designer kann optional Benachrichtigungen zu Designertransaktionsereignissen anzeigen. Wenn Sie während des Entwurfsmodus eine Instanz des DTComponent Formulars hinzufügen, wird ein Meldungsfeld angezeigt, in dem Sie gefragt werden, ob Sie Benachrichtigungen zu Designertransaktionsereignissen erhalten möchten. Sie können diese Benachrichtigungen über das Kontextmenü umschalten, das angezeigt wird, wenn Sie mit der rechten Maustaste auf eine Instanz der DTComponent. Transaktionen werden erstellt, wenn Sie Werte mithilfe des Eigenschaftenfenster ändern. Sie können auch festlegen, dass der Designer eine Transaktion ausführt, indem Sie im Kontextmenü für die Komponente auf " Beispieltransaktion ausführen " klicken.

#using <system.dll>
#using <system.design.dll>
#using <system.windows.forms.dll>

using namespace System;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::Design;

/*
This sample demonstrates how to perform a series of actions in a designer
transaction, how to change values of properties of a component from a
designer, and how to complete transactions without being interrupted
by other activities.

To run this sample, add this code to a class library project and compile.
Create a new Windows Forms project or load a form in the designer. Add a
reference to the class library that was compiled in the first step.
Right-click the Toolbox in design mode and click Customize Toolbox.
Browse to the class library that was compiled in the first step and
select OK until the DTComponent item appears in the Toolbox.  Add an
instance of this component to the form.

When the component is created and added to the component tray for your
design project, the Initialize method of the designer is called.
This method displays a message box informing you that designer transaction
event handlers will be registered unless you click Cancel. When you set
properties in the properties window, each change will be encapsulated in
a designer transaction, allowing the change to be undone later.

When you right-click the component, the shortcut menu for the component
is displayed. The designer constructs this menu according to whether
designer transaction notifications are enabled, and offers the option
of enabling or disabling the notifications, depending on the current
mode. The shortcut menu also presents a Perform Example Transaction
item, which will set the values of the component's StringProperty and
CountProperty properties. You can undo the last designer transaction using
the Undo command provided by the Visual Studio development environment.
*/

private ref class DTDesigner: public ComponentDesigner
{
private:
   bool notification_mode;
   int count;
   void LinkDTNotifications( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      if (  !notification_mode )
      {
         IDesignerHost^ host = dynamic_cast<IDesignerHost^>(GetService( IDesignerHost::typeid ));
         if ( host != nullptr )
         {
            notification_mode = true;
            host->TransactionOpened += gcnew EventHandler( this, &DTDesigner::OnDesignerTransactionOpened );
            host->TransactionClosed += gcnew DesignerTransactionCloseEventHandler( this, &DTDesigner::OnDesignerTransactionClosed );
         }
      }
   }

   void UnlinkDTNotifications( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      if ( notification_mode )
      {
         IDesignerHost^ host = dynamic_cast<IDesignerHost^>(GetService( IDesignerHost::typeid ));
         if ( host != nullptr )
         {
            notification_mode = false;
            host->TransactionOpened -= gcnew EventHandler( this, &DTDesigner::OnDesignerTransactionOpened );
            host->TransactionClosed -= gcnew DesignerTransactionCloseEventHandler( this, &DTDesigner::OnDesignerTransactionClosed );
         }
      }
   }

   void OnDesignerTransactionOpened( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      MessageBox::Show( "A Designer Transaction was started. (TransactionOpened)" );
   }

   void OnDesignerTransactionClosed( Object^ /*sender*/, DesignerTransactionCloseEventArgs^ /*e*/ )
   {
      MessageBox::Show( "A Designer Transaction was completed. (TransactionClosed)" );
   }

   void DoTransaction( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      IDesignerHost^ host = static_cast<IDesignerHost^>(GetService( IDesignerHost::typeid ));
      DesignerTransaction^ t = host->CreateTransaction( "Change Text and Size" );
      
      /* The code within the using statement is considered to be a single transaction.
              When the user selects Undo, the system will undo everything executed in this code block.
              */
      if ( notification_mode )
            MessageBox::Show( "Entering a Designer-Initiated Designer Transaction" );

      // The .NET Framework automatically associates the TypeDescriptor with the correct component
      PropertyDescriptor^ someText = TypeDescriptor::GetProperties( Component )[ "StringProperty" ];
      someText->SetValue( Component, "This text was set by the designer for this component." );
      PropertyDescriptor^ anInteger = TypeDescriptor::GetProperties( Component )[ "CountProperty" ];
      anInteger->SetValue( Component, count );
      count++;

      // Complete the designer transaction.
      t->Commit();
      if ( notification_mode )
            MessageBox::Show( "Designer-Initiated Designer Transaction Completed" );
   }

public:
   property DesignerVerbCollection^ Verbs 
   {
      // The Verbs property is overridden from ComponentDesigner
      virtual DesignerVerbCollection^ get() override
      {
         DesignerVerbCollection^ dvc = gcnew DesignerVerbCollection;
         dvc->Add( gcnew DesignerVerb( "Perform Example Transaction",gcnew EventHandler( this, &DTDesigner::DoTransaction ) ) );
         if ( notification_mode )
                  dvc->Add( gcnew DesignerVerb( "End Designer Transaction Notifications",
                     gcnew EventHandler( this, &DTDesigner::UnlinkDTNotifications ) ) );
         else
                  dvc->Add( gcnew DesignerVerb( "Show Designer Transaction Notifications",
                     gcnew EventHandler( this, &DTDesigner::LinkDTNotifications ) ) );

         return dvc;
      }
   }
   virtual void Initialize( IComponent^ component ) override
   {
      ComponentDesigner::Initialize( component );
      notification_mode = false;
      count = 10;
      IDesignerHost^ host = dynamic_cast<IDesignerHost^>(GetService( IDesignerHost::typeid ));
      if ( host == nullptr )
      {
         MessageBox::Show( "The IDesignerHost service interface could not be obtained." );
         return;
      }

      if ( MessageBox::Show( "Press the Yes button to display notification message boxes for the designer transaction opened and closed notifications.", "Link DesignerTransaction Notifications?", MessageBoxButtons::YesNo, MessageBoxIcon::Question, MessageBoxDefaultButton::Button1, MessageBoxOptions::RightAlign ) == DialogResult::Yes )
      {
         host->TransactionOpened += gcnew EventHandler( this, &DTDesigner::OnDesignerTransactionOpened );
         host->TransactionClosed += gcnew DesignerTransactionCloseEventHandler( this, &DTDesigner::OnDesignerTransactionClosed );
         notification_mode = true;
      }
   }

public:
   ~DTDesigner()
   {
      UnlinkDTNotifications( this, gcnew EventArgs );
   }
};

// Associate the DTDesigner with this component

[DesignerAttribute(DTDesigner::typeid)]
public ref class DTComponent: public System::ComponentModel::Component
{
private:
   String^ m_String;
   int m_Count;
   void InitializeComponent()
   {
      m_String = "Initial Value";
      m_Count = 0;
   }

public:
   property String^ StringProperty 
   {
      String^ get()
      {
         return m_String;
      }

      void set( String^ value )
      {
         m_String = value;
      }
   }

   property int CountProperty 
   {
      int get()
      {
         return m_Count;
      }

      void set( int value )
      {
         m_Count = value;
      }
   }
};

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;

/*
    This sample demonstrates how to perform a series of actions in a designer 
    transaction, how to change values of properties of a component from a 
    designer, and how to complete transactions without being interrupted 
    by other activities.

    To run this sample, add this code to a class library project and compile. 
    Create a new Windows Forms project or load a form in the designer. Add a 
    reference to the class library that was compiled in the first step.
    Right-click the Toolbox in design mode and click Customize Toolbox.  
    Browse to the class library that was compiled in the first step and 
    select OK until the DTComponent item appears in the Toolbox.  Add an 
    instance of this component to the form.  
    
    When the component is created and added to the component tray for your
    design project, the Initialize method of the designer is called. 
    This method displays a message box informing you that designer transaction
    event handlers will be registered unless you click Cancel. When you set 
    properties in the properties window, each change will be encapsulated in 
    a designer transaction, allowing the change to be undone later.  
    
    When you right-click the component,	the shortcut menu for the component 
    is displayed. The designer constructs this menu according to whether 
    designer transaction notifications are enabled, and offers the option
    of enabling or disabling the notifications, depending on the current 
    mode. The shortcut menu also presents a Perform Example Transaction 
    item, which will set the values of the component's StringProperty and 
    CountProperty properties. You can undo the last designer transaction using 
    the Undo command provided by the Visual Studio development environment.
*/

namespace DesignerTransactionSample
{
    // Associate the DTDesigner with this component
    [DesignerAttribute(typeof(DTDesigner))]
    public class DTComponent : System.ComponentModel.Component
    {
        private string m_String;
    private int m_Count;
            
    public string StringProperty
    {
        get
            { return m_String; }
        set
        { m_String = value; }
    }
            
    public int CountProperty
    {
        get
        { return m_Count; }
        set
        { m_Count = value; }
    }

    private void InitializeComponent()
    {
        m_String = "Initial Value";
        m_Count = 0;
    }
    }
    
    internal class DTDesigner : ComponentDesigner
    {
    private bool notification_mode = false;
    private int count = 10;
        
    // The Verbs property is overridden from ComponentDesigner
    public override DesignerVerbCollection Verbs
    {
        get
        {				
            DesignerVerbCollection dvc = new DesignerVerbCollection();				
        dvc.Add( new DesignerVerb("Perform Example Transaction", new EventHandler(this.DoTransaction)) );
        if(notification_mode)
            dvc.Add(new DesignerVerb("End Designer Transaction Notifications", new EventHandler(this.UnlinkDTNotifications)));
        else
            dvc.Add(new DesignerVerb("Show Designer Transaction Notifications", new EventHandler(this.LinkDTNotifications)));				return dvc;
        }
    }
        
        public override void Initialize(System.ComponentModel.IComponent component)
        {
            base.Initialize(component);

            IDesignerHost host = (IDesignerHost)GetService(typeof(IDesignerHost));			
            if(host == null)
            {
                MessageBox.Show("The IDesignerHost service interface could not be obtained.");
                return;
            }

            if( MessageBox.Show("Press the Yes button to display notification message boxes for the designer transaction opened and closed notifications.","Link DesignerTransaction Notifications?", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1, MessageBoxOptions.RightAlign) == DialogResult.Yes )
            {							
            host.TransactionOpened += new EventHandler(OnDesignerTransactionOpened);
                host.TransactionClosed += new DesignerTransactionCloseEventHandler(OnDesignerTransactionClosed);
                notification_mode = true;
            }
        }
        
        private void LinkDTNotifications(object sender, EventArgs e)
        {
            if(!notification_mode)
            {
            IDesignerHost host = (IDesignerHost)GetService(typeof(IDesignerHost));							
                if(host != null)
            {
            notification_mode = true;
                   host.TransactionOpened += new EventHandler(OnDesignerTransactionOpened);
                   host.TransactionClosed += new DesignerTransactionCloseEventHandler(OnDesignerTransactionClosed);
            }
        }
        }

        private void UnlinkDTNotifications(object sender, EventArgs e)
        {
        if(notification_mode)
            {
                IDesignerHost host = (IDesignerHost)GetService(typeof(IDesignerHost));							
            if(host != null)
                {				
            notification_mode = false;
                    host.TransactionOpened -= new EventHandler(OnDesignerTransactionOpened);
                    host.TransactionClosed -= new DesignerTransactionCloseEventHandler(OnDesignerTransactionClosed);
                }
            }
        }

        private void OnDesignerTransactionOpened(object sender, EventArgs e)
        {			
        System.Windows.Forms.MessageBox.Show("A Designer Transaction was started. (TransactionOpened)");
        }

        private void OnDesignerTransactionClosed(object sender, DesignerTransactionCloseEventArgs e)
        {			
        System.Windows.Forms.MessageBox.Show("A Designer Transaction was completed. (TransactionClosed)");
        }   

        private void DoTransaction(object sender, EventArgs e) 
        {			
            IDesignerHost host = (IDesignerHost)GetService(typeof(IDesignerHost));			
            DesignerTransaction t = host.CreateTransaction("Change Text and Size");

            /* The code within the using statement is considered to be a single transaction.
           When the user selects Undo, the system will undo everything executed in this code block. */
            using (t)
            {
            if(notification_mode)
                System.Windows.Forms.MessageBox.Show("Entering a Designer-Initiated Designer Transaction");
                
                // The .NET Framework automatically associates the TypeDescriptor with the correct component
            PropertyDescriptor someText = TypeDescriptor.GetProperties(Component)["StringProperty"];
                someText.SetValue(Component, "This text was set by the designer for this component.");

                PropertyDescriptor anInteger = TypeDescriptor.GetProperties(Component)["CountProperty"];
            anInteger.SetValue(Component, count);
            count++;

                // Complete the designer transaction.
            t.Commit();
                
            if(notification_mode)
                System.Windows.Forms.MessageBox.Show("Designer-Initiated Designer Transaction Completed");
            }
        }
        
    protected override void Dispose(bool disposing)
    {
        UnlinkDTNotifications(this, new EventArgs());
        base.Dispose(disposing);
    }
    }
}

Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

'   This sample demonstrates how to perform a series of actions in a designer 
'   transaction, how to change values of properties of a component from a 
'   designer, and how to complete transactions without being interrupted 
'   by other activities.

'   To run this sample, add this code to a class library project and compile. 
'   Create a new Windows Forms project or load a form in the designer. Add a 
'   reference to the class library that was compiled in the first step.
'   Right-click the Toolbox in design mode and click Customize Toolbox.  
'   Browse to the class library that was compiled in the first step and 
'   select OK until the DTComponent item appears in the Toolbox.  Add an 
'   instance of this component to the form.  

'   When the component is created and added to the component tray for your
'   design project, the Initialize method of the designer is called. 
'   This method displays a message box informing you that designer transaction
'   event handlers are being registered unless you click Cancel. When you set 
'   properties in the properties window, each change will be encapsulated in 
'   a designer transaction, allowing the change to be undone later.  

'   When you right-click the component, the shortcut menu for the component 
'   is displayed. The designer constructs this menu according to whether 
'   designer transaction notifications are enabled, and offers the option
'   of enabling or disabling the notifications, depending on the current 
'   mode. The shortcut menu also presents a Perform Example Transaction 
'   item which will set the values of the component's StringProperty and 
'   CountProperty properties. You can undo the last designer transaction using 
'   the Undo command provided by the Visual Studio development environment.	

Namespace DesignerTransactionSample

    ' Associate the DTDesigner with this component
    <DesignerAttribute(GetType(DTDesigner))> _
    Public Class DTComponent
        Inherits System.ComponentModel.Component
        Private m_String As String
        Private m_Count As Integer

        Public Property StringProperty() As String
            Get
                Return m_String
            End Get
            Set(ByVal Value As String)
                m_String = Value
            End Set
        End Property

        Public Property CountProperty() As Integer
            Get
                Return m_Count
            End Get
            Set(ByVal Value As Integer)
                m_Count = Value
            End Set
        End Property

        Private Sub InitializeComponent()
            m_String = "Initial Value"
            m_Count = 0
        End Sub

    End Class

    Friend Class DTDesigner
        Inherits ComponentDesigner

        Private notification_mode As Boolean = False
        Private count As Integer = 10

        ' The Verbs property is overridden from ComponentDesigner
        Public Overrides ReadOnly Property Verbs() As DesignerVerbCollection
            Get
                Dim dvc As New DesignerVerbCollection()
                dvc.Add(New DesignerVerb("Perform Example Transaction", AddressOf Me.DoTransaction))
                If notification_mode Then
                    dvc.Add(New DesignerVerb("End Designer Transaction Notifications", AddressOf Me.UnlinkDTNotifications))
                Else
                    dvc.Add(New DesignerVerb("Show Designer Transaction Notifications", AddressOf Me.LinkDTNotifications))
                End If
                Return dvc
            End Get
        End Property

        Public Overrides Sub Initialize(ByVal component As System.ComponentModel.IComponent)
            MyBase.Initialize(component)

            Dim host As IDesignerHost = CType(GetService(GetType(IDesignerHost)), IDesignerHost)
            If host Is Nothing Then
                MessageBox.Show("The IDesignerHost service interface could not be obtained.")
                Return
            End If

            If MessageBox.Show("Press the Yes button to display notification message boxes for the designer transaction opened and closed notifications.", "Link DesignerTransaction Notifications?", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1, MessageBoxOptions.RightAlign) = DialogResult.Yes Then
                AddHandler host.TransactionOpened, AddressOf OnDesignerTransactionOpened
                AddHandler host.TransactionClosed, AddressOf OnDesignerTransactionClosed
                notification_mode = True
            End If
        End Sub

        Private Sub LinkDTNotifications(ByVal sender As Object, ByVal e As EventArgs)
            If notification_mode = False Then
                Dim host As IDesignerHost = CType(GetService(GetType(IDesignerHost)), IDesignerHost)
                If (host IsNot Nothing) Then
                    notification_mode = True
                    AddHandler host.TransactionOpened, AddressOf OnDesignerTransactionOpened
                    AddHandler host.TransactionClosed, AddressOf OnDesignerTransactionClosed
                End If
            End If
        End Sub

        Private Sub UnlinkDTNotifications(ByVal sender As Object, ByVal e As EventArgs)
            If notification_mode Then
                Dim host As IDesignerHost = CType(GetService(GetType(IDesignerHost)), IDesignerHost)
                If (host IsNot Nothing) Then
                    notification_mode = False
                    RemoveHandler host.TransactionOpened, AddressOf Me.OnDesignerTransactionOpened
                    RemoveHandler host.TransactionClosed, AddressOf Me.OnDesignerTransactionClosed
                End If
            End If
        End Sub

        Private Sub OnDesignerTransactionOpened(ByVal sender As Object, ByVal e As EventArgs)
            System.Windows.Forms.MessageBox.Show("A Designer Transaction was started. (TransactionOpened)")
        End Sub

        Private Sub OnDesignerTransactionClosed(ByVal sender As Object, ByVal e As DesignerTransactionCloseEventArgs)
            System.Windows.Forms.MessageBox.Show("A Designer Transaction was completed. (TransactionClosed)")
        End Sub

        Private Sub DoTransaction(ByVal sender As Object, ByVal e As EventArgs)
            Dim host As IDesignerHost = CType(GetService(GetType(IDesignerHost)), IDesignerHost)
            Dim t As DesignerTransaction = host.CreateTransaction("Change Text and Size")

            ' The code within the using statement is considered to be a single transaction.
            ' When the user selects Undo, the system will undo everything executed in this code block. 
            Try
                If (notification_mode) Then
                    System.Windows.Forms.MessageBox.Show("Entering a Designer-Initiated Designer Transaction")
                End If

                Dim someText As PropertyDescriptor = TypeDescriptor.GetProperties(Component)("StringProperty")
                someText.SetValue(Component, "This text was set by the designer for this component.")
                Dim anInteger As PropertyDescriptor = TypeDescriptor.GetProperties(Component)("CountProperty")
                anInteger.SetValue(Component, count)
                count = count + 1

                Exit Try
            Finally
                t.Commit()                
            End Try
            If (notification_mode) Then
                System.Windows.Forms.MessageBox.Show("Designer-Initiated Designer Transaction Completed")
            End If
        End Sub

        Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
            UnlinkDTNotifications(Me, New EventArgs())
            MyBase.Dispose(disposing)
        End Sub

    End Class
End Namespace 'DesignerTransactionSample

Hinweise

Transaktionen können Aktionen nachverfolgen, die später rückgängig gemacht werden können. Änderungen, die während einer Transaktion vorgenommen wurden, können rückgängig gemacht werden, indem eine Transaktion abgebrochen wird, wodurch automatisch versucht wird, jede Änderung rückgängig zu machen, indem jede geänderte Eigenschaft auf den Voränderungswert festgelegt wird. Transaktionen können auch die Leistung während einer Reihe von Vorgängen verbessern, indem Aktualisierungen auf die Anzeige zurückstellen, bis der Abschluss der Transaktion abgeschlossen ist.

Wenn eine Transaktion ausgeführt wird, verzögern einige Komponenten ihre Verarbeitung, bis die Transaktion abgeschlossen wurde, indem sie auf die TransactionOpening Ereignisse TransactionClosed lauschen. Die Eigenschaftenfenster aktualisiert beispielsweise die Anzeige erst, nachdem eine Transaktion geöffnet wurde, bis die Transaktion geschlossen wurde.

Wenn Sie Transaktionen für umkehrbare oder mehrere Vorgänge verwenden möchten, erstellen Sie vom Designer einen DesignerTransaction für jeden Vorgang oder jede Reihe von Vorgängen, die umkehrbar sein sollten. Achten Sie darauf, keine Aktionen außerhalb der Transaktionen auszuführen, die verhindern können, dass eine Folge von Rückgängig-Ereignissen erfolgreich abgeschlossen wird.

Sie können ein neues DesignerTransaction abrufen, indem Sie die CreateTransaction Methode einer IDesignerHost. Stellen Sie sicher, dass Sie die einzelnen DesignerTransaction Elemente aus dem aktiven IDesignerHost Abrufen erhalten, um sie ordnungsgemäß in den Designertransaktionsverarbeitungsmechanismus zu integrieren, anstatt eine neue DesignerTransaction direkt zu erstellen.

Zum Ausführen einer Aktion innerhalb einer Transaktion müssen Sie zuerst eine Transaktion erstellen. Anschließend müssen Sie die OnComponentChanging Methode aufrufen, bevor jede Änderung oder gruppe von Änderungen eintritt, und die OnComponentChanged Methode nach jeder Änderung oder gruppe von Änderungen tritt auf. Schließen Sie schließlich die Transaktion ab, indem Sie die Commit Methode aufrufen.

Führen Sie zum Ausführen einer Transaktion die folgenden Schritte aus:

1. Rufen Sie auf, um einen DesignerTransaction Aufruf CreateTransaction abzurufen, der zum Steuern der Transaktion verwendet werden kann.

2. Rufen Sie innerhalb eines try Blocks für jede Aktion, die Sie nachverfolgen DesignerTransactionmöchten, die OnComponentChanging Methode auf, nehmen Sie die Änderung oder Änderungen vor, und rufen Sie dann die OnComponentChanged Methode auf, um zu signalisieren, dass die Änderung oder Änderungen vorgenommen wurden.

3. Um die Transaktion abzuschließen, rufen Sie Commit innerhalb eines finally Blocks auf.

In C# können Sie die using Anweisung anstelle eines try/finally Blocks verwenden, z. B. im folgenden Beispiel.

using (host.CreateTransaction() {
// Insert your code here.
}

Rufen Sie die Cancel Methode auf, um eine Transaktion abzubrechen und ein Rollback durchzuführen, bevor sie zugesichert wurde. Wenn die Cancel Methode aufgerufen wird, werden die aktionen, die von der DesignerTransaction Methode nachverfolgt werden, um zu versuchen, das Rollback der Änderungen rückgängig zu machen. Um Aktionen rückgängig zu machen, die als Teil früherer Transaktionen aufgetreten sind, müssen Sie den Befehl "Rückgängig" verwenden, der von der Entwicklungsumgebung bereitgestellt wird.

Weitere Informationen

• IDesignerHost
• IComponentChangeService
• PropertyDescriptor