DesignerTransaction Класс

Определение

Предоставляет способ сгруппировать последовательность действий этапа разработки, что позволяет повысить производительность и дает возможность отменять действия большинства типов.Provides a way to group a series of design-time actions to improve performance and enable most types of changes to be undone.

public ref class DesignerTransaction abstract : IDisposable
public abstract class DesignerTransaction : IDisposable
type DesignerTransaction = class
    interface IDisposable
Public MustInherit Class DesignerTransaction
Implements IDisposable
Наследование
DesignerTransaction
Реализации

Примеры

В следующем примере программы показано, как создать DesignerTransaction из конструктора.The following code example program demonstrates how to create a DesignerTransaction from a designer. Чтобы запустить этот пример, Скомпилируйте исходный код в библиотеку классов.To run this sample, compile the source code into a class library. Необходимо добавить ссылку на сборку System. Design.You must add a reference to the System.Design assembly. В новом проекте добавьте ссылку на скомпилированную библиотеку DLL и добавьте компонент в библиотеку на панель элементов.In a new project, add a reference to the compiled DLL and add the component in the library to the Toolbox.

В Visual Studio реализована расширенная поддержка этой функции.There is extensive support for this feature in Visual Studio.

См. также раздел Пошаговое руководство. Автоматическое заполнение панели элементов пользовательскими компонентами.Also see Walkthrough: Automatically Populating the Toolbox with Custom Components.

Конструктор может при необходимости отображать уведомления о событиях транзакций конструктора.The designer can optionally display notifications about designer transaction events. При добавлении экземпляра DTComponent в форму в режиме конструктора появляется окно сообщения с вопросом о том, хотите ли вы получать уведомления о событиях транзакций в конструкторе.If you add an instance of the DTComponent to a form while in design mode, a message box appears asking whether you would like to receive designer transaction event notifications. Эти уведомления можно переключать с помощью контекстного меню, отображаемого при щелчке правой кнопкой мыши экземпляра DTComponent.You may toggle these notifications using the shortcut menu that appears when you right-click an instance of the DTComponent. Транзакции создаются при изменении значений с помощью окно свойств.Transactions are created when you change values using the Properties window. Кроме того, конструктор может выполнить транзакцию, щелкнув выполнить пример транзакции в контекстном меню компонента.You can also have the designer perform a transaction by clicking Perform Example Transaction on the shortcut menu for the component.

#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 == false)
            {
            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

Комментарии

Транзакции могут относиться к действиям, которые могут быть отменены позже.Transactions can track actions that can be undone later. Изменения, внесенные во время транзакции, можно отменять, отменяя транзакцию, которая автоматически пытается отменить каждое изменение, присвоив каждому измененному свойству значение предварительного изменения.Changes made during a transaction can be reversed by canceling a transaction, which automatically attempts to reverse each change by setting each changed property to its pre-change value. Транзакции также могут повысить производительность во время выполнения последовательности операций, откладывая обновления на экране до завершения транзакции.Transactions can also improve performance during a series of operations by deferring updates to the display until the completion of the transaction.

При выполнении транзакции некоторые компоненты откладывают свою обработку до тех пор, пока транзакция не будет завершена путем прослушивания событий TransactionOpening и TransactionClosed.When a transaction is in progress, some components defer their processing until the transaction has completed by listening to the TransactionOpening and TransactionClosed events. Окно свойств, например, не обновляет его отображение после открытия транзакции до закрытия транзакции.The Properties window, for example, does not update its display after a transaction has opened until the transaction has closed.

Чтобы использовать транзакции для обратимого или нескольких операций, конструктор должен создать DesignerTransaction для каждой операции или ряда операций, которые должны быть обратимыми.To use transactions for reversible or multiple operations, have your designer create a DesignerTransaction for each operation or series of operations which should be reversible. Будьте внимательны, чтобы не выполнять действия за пределами транзакций, которые могут препятствовать успешному завершению последовательности событий отмены.Be careful not to perform actions outside the transactions that might prevent a sequence of undo events from completing successfully.

Новый DesignerTransaction можно получить, вызвав метод CreateTransaction IDesignerHost.You can obtain a new DesignerTransaction by calling the CreateTransaction method of an IDesignerHost. Не забудьте получить каждый DesignerTransaction из Active IDesignerHost, чтобы правильно интегрироваться с механизмом обработки транзакций конструктора, вместо того, чтобы создавать новый DesignerTransaction напрямую.Be sure to obtain each DesignerTransaction from the active IDesignerHost in order to correctly integrate with the designer transaction processing mechanism, rather than creating a new DesignerTransaction directly.

Чтобы выполнить действие в рамках транзакции, необходимо сначала создать транзакцию.To perform an action within a transaction, you must first create a transaction. Затем необходимо вызвать метод OnComponentChanging перед каждым изменением или набором изменений, а также метод OnComponentChanged после каждого изменения или набора изменений.Then you must call the OnComponentChanging method before each change or set of changes occurs, and the OnComponentChanged method after each change or set of changes occur. Наконец, завершите и закройте транзакцию, вызвав метод Commit.Finally, complete and close the transaction by calling the Commit method.

Примечание

При внесении изменений в значения свойств используйте метод SetValue PropertyDescriptor, который вызывает методы изменения компонента IComponentChangeService и создает DesignerTransaction, представляющий изменение автоматически.When making changes to property values, use the SetValue method of a PropertyDescriptor, which calls the component change methods of the IComponentChangeService and creates a DesignerTransaction representing the change automatically.

Чтобы выполнить транзакцию, выполните следующие действия.To perform a transaction, complete the following steps:

  1. Вызовите CreateTransaction, чтобы получить DesignerTransaction, который можно использовать для управления транзакцией.Call CreateTransaction to obtain a DesignerTransaction that can be used to control the transaction.

  2. В блоке try для каждого действия, которое необходимо отвести от DesignerTransaction, вызовите метод OnComponentChanging, внесите изменения или изменения, а затем вызовите метод OnComponentChanged, чтобы сообщить об изменении или внесении изменений.Within a try block, for each action that you want to track with a DesignerTransaction, call the OnComponentChanging method, make the change or changes, then call the OnComponentChanged method to signal that the change or changes have been made.

  3. Чтобы завершить транзакцию, вызовите Commit в блоке finally.To complete the transaction, call Commit from within a finally block.

В C#можно использовать оператор using, а не блок try/finally, как показано в следующем примере.In C#, you can use the using statement rather than a try/finally block, such as in the following example.

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

Чтобы отменить операцию и попытаться выполнить откат транзакции до ее фиксации, вызовите метод Cancel.To cancel and attempt to roll back a transaction before it has been committed, call the Cancel method. При вызове метода Cancel действия, которые отправляются DesignerTransaction, отменяются для попыток отката изменений.When the Cancel method is invoked, the actions tracked by the DesignerTransaction are reversed to attempt to roll back the changes. Чтобы отменить действия, которые произошли в рамках предыдущих транзакций, необходимо использовать команду Undo, предоставленную средой разработки.To undo actions that occurred as part of earlier transactions, you must use the undo command provided by the development environment.

Конструкторы

DesignerTransaction()

Инициализирует новый экземпляр класса DesignerTransaction без описания.Initializes a new instance of the DesignerTransaction class with no description.

DesignerTransaction(String)

Инициализирует новый экземпляр класса DesignerTransaction с помощью указанного описания транзакции.Initializes a new instance of the DesignerTransaction class using the specified transaction description.

Свойства

Canceled

Возвращает значение, определяющее, была ли отменена данная транзакция.Gets a value indicating whether the transaction was canceled.

Committed

Возвращает значение, определяющее, была ли зафиксирована данная транзакция.Gets a value indicating whether the transaction was committed.

Description

Возвращает описание транзакции.Gets a description for the transaction.

Методы

Cancel()

Отменяет транзакцию и пытается отменить все действия, выполненные событиями транзакции.Cancels the transaction and attempts to roll back the changes made by the events of the transaction.

Commit()

Фиксирует транзакцию.Commits this transaction.

Dispose(Boolean)

Освобождает неуправляемые ресурсы, используемые объектом DesignerTransaction, а при необходимости освобождает также управляемые ресурсы.Releases the unmanaged resources used by the DesignerTransaction and optionally releases the managed resources.

Equals(Object)

Определяет, равен ли заданный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Унаследовано от Object)
Finalize()

Освобождает ресурсы, связанные с данным объектом.Releases the resources associated with this object. Этот метод фиксирует транзакцию, если она не была зафиксирована ранее.This override commits this transaction if it was not already committed.

GetHashCode()

Служит хэш-функцией по умолчанию.Serves as the default hash function.

(Унаследовано от Object)
GetType()

Возвращает объект Type для текущего экземпляра.Gets the Type of the current instance.

(Унаследовано от Object)
MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Унаследовано от Object)
OnCancel()

Вызывает событие Cancel.Raises the Cancel event.

OnCommit()

Фактически фиксирует транзакцию.Performs the actual work of committing a transaction.

ToString()

Возвращает строку, представляющую текущий объект.Returns a string that represents the current object.

(Унаследовано от Object)

Явные реализации интерфейса

IDisposable.Dispose()

Освобождает все ресурсы, занятые модулем DesignerTransaction.Releases all resources used by the DesignerTransaction.

Безопасность

NamedPermissionSet
для полного доступа к системным ресурсам.for full access to system resources. Значение требования: InheritanceDemand.Demand value: InheritanceDemand. Связанное состояние:Associated state:

Применяется к

Дополнительно