IEventBindingService-Schnittstelle
Stellt einen Dienst zum Registrieren von Ereignishandlern für Komponentenereignisse bereit.
Namespace: System.ComponentModel.Design
Assembly: System (in system.dll)
Syntax
'Declaration
<ComVisibleAttribute(True)> _
Public Interface IEventBindingService
'Usage
Dim instance As IEventBindingService
[ComVisibleAttribute(true)]
public interface IEventBindingService
[ComVisibleAttribute(true)]
public interface class IEventBindingService
/** @attribute ComVisibleAttribute(true) */
public interface IEventBindingService
ComVisibleAttribute(true)
public interface IEventBindingService
Hinweise
Mit dem Dienst für die Ereignisbindung kann ein Ereignishandler mit einem Komponentenereignis aus dem Designercode verknüpft werden.
Um einen Ereignishandler mithilfe des IEventBindingService mit einem Komponentenereignis zu verknüpfen, müssen Sie zunächst einen EventDescriptor für das Ereignis der zu verknüpfenden Komponente abrufen. Der IEventBindingService stellt Methoden bereit, mit denen ein EventDescriptor in einen PropertyDescriptor konvertiert werden kann, mit dem Sie das Ereignis mit dem Namen einer Ereignishandlermethode konfigurieren können.
Das TypeDescriptor-Objekt stellt eine GetEvents-Methode bereit, mit der Sie eine EventDescriptorCollection abrufen können, die EventDescriptor-Objekte für jedes Ereignis einer Komponente enthält. Die GetEventProperty-Methode und die GetEventProperties-Methode des IEventBindingService geben einen PropertyDescriptor für jeden EventDescriptor zurück, der an eine der Methoden übergeben wurde. Der Eigenschaftentyp jedes PropertyDescriptor, der von GetEventProperty oder von GetEventProperties zurückgegeben wird, ist string. Mit der SetValue-Methode des PropertyDescriptor können Sie diese Zeichenfolge auf einen Wert festlegen, der den Namen der Ereignishandlermethode angibt, mit der das Ereignis verknüpft werden soll.
Beispiel
Im folgenden Beispiel wird ein Designer veranschaulicht, der den IEventBindingService verwendet, um zur Entwurfszeit das Ereignis einer Komponente mit einem Ereignishandler zu verknüpfen, wenn der vom Designer für die Komponente hinzugefügte benutzerdefinierte Kontextmenübefehl aufgerufen wird. Um das Beispiel zu verwenden, kompilieren Sie es in eine Klassenbibliothek, und fügen Sie einen Verweis aus einem Windows Forms-Projekt hinzu. Fügen Sie der Toolbox anschließend die Komponente in der Klassenbibliothek hinzu, indem Sie mit der rechten Maustaste auf die Toolbox klicken, den Befehl Toolbox anpassen auswählen, die Klassenbibliothek auswählen und auf OK klicken. Fügen Sie dann einem Formular eine EventControl-Instanz hinzu. Klicken Sie mit der rechten Maustaste auf EventControl, und wählen Sie im Kontextmenü den Befehl zum Verbinden von testEvent aus. Eine leere Ereignishandlermethode wird erstellt, und die testEvent-Methode von EventControl wird im Initialisierungscode für das Formular mit diesem Ereignishandler initialisiert.
Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Data
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.Design
Namespace EventDesignerTest
' This designer provides a "Connect testEvent" designer verb shortcut
' menu command. When invoked, the command attaches a new event-handler
' method named "testEventHandler" to the "testEvent" event of an
' associated control.
' If a "testEvent" event of the associated control does not exist,
' the IEventBindingService declares it.
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Public Class EventDesigner
Inherits System.Windows.Forms.Design.ControlDesigner
Public Sub New()
End Sub
' When the "Connect testEvent" designer verb shortcut menu
' command is invoked, this method uses the
' IEventBindingService to attach an event handler to a "textEvent" event of the associated control.
Private Sub ConnectEvent(ByVal sender As Object, ByVal e As EventArgs)
Dim eventservice As IEventBindingService = CType(Me.Component.Site.GetService(GetType(System.ComponentModel.Design.IEventBindingService)), IEventBindingService)
If Not (eventservice Is Nothing) Then
' Attempt to obtain a PropertyDescriptor for a
' component event named "testEvent".
Dim edc As EventDescriptorCollection = TypeDescriptor.GetEvents(Me.Component)
If edc Is Nothing Or edc.Count = 0 Then
Return
End If
Dim ed As EventDescriptor = Nothing
' Search for an event named "testEvent".
Dim edi As EventDescriptor
For Each edi In edc
If edi.Name = "testEvent" Then
ed = edi
Exit For
End If
Next edi
If ed Is Nothing Then
Return
End If
' Use the IEventBindingService to get a
' PropertyDescriptor for the event.
Dim pd As PropertyDescriptor = eventservice.GetEventProperty(ed)
If pd Is Nothing Then
Return
End If
' Set the value of the event to "testEventHandler".
pd.SetValue(Me.Component, "testEventHandler")
End If
End Sub
' Provides a designer verb command for the designer's
' shortcut menu.
Public Overrides ReadOnly Property Verbs() As System.ComponentModel.Design.DesignerVerbCollection
Get
Dim dvc As New DesignerVerbCollection()
dvc.Add(New DesignerVerb("Connect testEvent", New EventHandler(AddressOf ConnectEvent)))
Return dvc
End Get
End Property
End Class
' EventControl is associated with the EventDesigner and displays
' instructions for demonstrating the service.
<Designer(GetType(EventDesigner))> _
Public Class EventControl
Inherits System.Windows.Forms.UserControl
Public Event testEvent As System.EventHandler
Public Sub New()
Me.BackColor = Color.White
Me.Size = New Size(320, 96)
End Sub
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
MyBase.Dispose(disposing)
End Sub
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
e.Graphics.DrawString("IEventBindingService Example Control", New Font(FontFamily.GenericMonospace, 10), New SolidBrush(Color.Blue), 5, 5)
e.Graphics.DrawString("Use the ""Connect testEvent"" command of the", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 22)
e.Graphics.DrawString("right-click shortcut menu provided by this", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 32)
e.Graphics.DrawString("control's associated EventDesigner to create", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 42)
e.Graphics.DrawString("a new event handler linked with the testEvent", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 52)
e.Graphics.DrawString("of this control in the initialization code", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 62)
e.Graphics.DrawString("for this control.", New Font(FontFamily.GenericMonospace, 8), New SolidBrush(Color.Black), 5, 72)
End Sub
End Class
End Namespace
using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Windows.Forms.Design;
namespace EventDesignerTest
{
// This designer provides a "Connect testEvent" designer verb shortcut
// menu command. When invoked, the command attaches a new event-handler
// method named "testEventHandler" to the "testEvent" event of an
// associated control.
// If a "testEvent" event of the associated control does not exist,
// the IEventBindingService declares it.
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
public class EventDesigner : System.Windows.Forms.Design.ControlDesigner
{
public EventDesigner()
{
}
// When the "Connect testEvent" designer verb shortcut menu
// command is invoked, this method uses the
// IEventBindingService to attach an event handler to a
// "textEvent" event of the associated control.
private void ConnectEvent(object sender, EventArgs e)
{
IEventBindingService eventservice = (IEventBindingService)this.Component.Site.GetService(typeof(System.ComponentModel.Design.IEventBindingService));
if( eventservice != null )
{
// Attempt to obtain a PropertyDescriptor for a
// component event named "testEvent".
EventDescriptorCollection edc = TypeDescriptor.GetEvents(this.Component);
if( edc == null || edc.Count == 0 )
return;
EventDescriptor ed = null;
// Search for an event named "testEvent".
foreach(EventDescriptor edi in edc)
if(edi.Name == "testEvent")
{
ed = edi;
break;
}
if( ed == null )
return;
// Use the IEventBindingService to get a
// PropertyDescriptor for the event.
PropertyDescriptor pd = eventservice.GetEventProperty(ed);
if( pd == null )
return;
// Set the value of the event to "testEventHandler".
pd.SetValue(this.Component, "testEventHandler");
}
}
// Provides a designer verb command for the designer's
// shortcut menu.
public override System.ComponentModel.Design.DesignerVerbCollection Verbs
{
get
{
DesignerVerbCollection dvc = new DesignerVerbCollection();
dvc.Add(new DesignerVerb("Connect testEvent", new EventHandler(ConnectEvent)));
return dvc;
}
}
}
// EventControl is associated with the EventDesigner and displays
// instructions for demonstrating the service.
[Designer(typeof(EventDesigner))]
public class EventControl : System.Windows.Forms.UserControl
{
public event System.EventHandler testEvent;
public EventControl()
{
this.BackColor = Color.White;
this.Size = new Size(320, 96);
}
protected override void Dispose( bool disposing )
{
base.Dispose( disposing );
}
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
e.Graphics.DrawString("IEventBindingService Example Control", new Font(FontFamily.GenericMonospace, 10), new SolidBrush(Color.Blue), 5, 5);
e.Graphics.DrawString("Use the \"Connect testEvent\" command of the", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 22);
e.Graphics.DrawString("right-click shortcut menu provided by this", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 32);
e.Graphics.DrawString("control's associated EventDesigner to create", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 42);
e.Graphics.DrawString("a new event handler linked with the testEvent", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 52);
e.Graphics.DrawString("of this control in the initialization code", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 62);
e.Graphics.DrawString("for this control.", new Font(FontFamily.GenericMonospace, 8), new SolidBrush(Color.Black), 5, 72);
}
}
}
#using <System.Windows.Forms.dll>
#using <System.Data.dll>
#using <System.Drawing.dll>
#using <System.Design.dll>
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Drawing;
using namespace System::Data;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::Design;
using namespace System::Security::Permissions;
// This designer provides a "Connect testEvent" designer verb shortcut
// menu command. When invoked, the command attaches a new event-handler
// method named "testEventHandler" to the "testEvent" event of an
// associated control.
// If a "testEvent" event of the associated control does not exist,
// the IEventBindingService declares it.
public ref class EventDesigner: public System::Windows::Forms::Design::ControlDesigner
{
public:
EventDesigner(){}
// When the "Connect testEvent" designer verb shortcut menu
// command is invoked, this method uses the
// IEventBindingService to attach an event handler to a
// "textEvent" event of the associated control.
private:
void ConnectEvent( Object^ /*sender*/, EventArgs^ /*e*/ )
{
IEventBindingService^ eventservice = dynamic_cast<IEventBindingService^>(this->Component->Site->GetService( System::ComponentModel::Design::IEventBindingService::typeid ));
if ( eventservice != nullptr )
{
// Attempt to obtain a PropertyDescriptor for a
// component event named "testEvent".
EventDescriptorCollection^ edc = TypeDescriptor::GetEvents( this->Component );
if ( edc == nullptr || edc->Count == 0 )
return;
EventDescriptor^ ed = nullptr;
// Search for an event named "testEvent".
IEnumerator^ myEnum = edc->GetEnumerator();
while ( myEnum->MoveNext() )
{
EventDescriptor^ edi = safe_cast<EventDescriptor^>(myEnum->Current);
if ( edi->Name->Equals( "testEvent" ) )
{
ed = edi;
break;
}
}
if ( ed == nullptr )
return;
// Use the IEventBindingService to get a
// PropertyDescriptor for the event.
PropertyDescriptor^ pd = eventservice->GetEventProperty( ed );
if ( pd == nullptr )
return;
// Set the value of the event to "testEventHandler".
pd->SetValue( this->Component, "testEventHandler" );
}
}
public:
property System::ComponentModel::Design::DesignerVerbCollection^ Verbs
{
// Provides a designer verb command for the designer's
// shortcut menu.
[PermissionSetAttribute(SecurityAction::Demand, Name="FullTrust")]
virtual System::ComponentModel::Design::DesignerVerbCollection^ get() override
{
DesignerVerbCollection^ dvc = gcnew DesignerVerbCollection;
dvc->Add( gcnew DesignerVerb( "Connect testEvent",gcnew EventHandler( this, &EventDesigner::ConnectEvent ) ) );
return dvc;
}
}
};
// EventControl is associated with the EventDesigner and displays
// instructions for demonstrating the service.
[Designer(EventDesigner::typeid)]
public ref class EventControl: public System::Windows::Forms::UserControl
{
public:
event System::EventHandler^ testEvent;
EventControl()
{
this->BackColor = Color::White;
this->Size = System::Drawing::Size( 320, 96 );
}
public:
~EventControl()
{
}
protected:
virtual void OnPaint( System::Windows::Forms::PaintEventArgs^ e ) override
{
e->Graphics->DrawString( "IEventBindingService Example Control", gcnew System::Drawing::Font( FontFamily::GenericMonospace,10 ), gcnew SolidBrush( Color::Blue ), 5, 5 );
e->Graphics->DrawString( "Use the \"Connect testEvent\" command of the", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 22 );
e->Graphics->DrawString( "right-click shortcut menu provided by this", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 32 );
e->Graphics->DrawString( "control's associated EventDesigner to create", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 42 );
e->Graphics->DrawString( "a new event handler linked with the testEvent", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 52 );
e->Graphics->DrawString( "of this control in the initialization code", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 62 );
e->Graphics->DrawString( "for this control.", gcnew System::Drawing::Font( FontFamily::GenericMonospace,8 ), gcnew SolidBrush( Color::Black ), 5, 72 );
}
};
Plattformen
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
IEventBindingService-Member
System.ComponentModel.Design-Namespace
PropertyDescriptor-Klasse
EventDescriptor-Klasse
PropertyDescriptorCollection-Klasse
EventDescriptorCollection-Klasse