IEventBindingService Interface
Definição
Importante
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Fornece um serviço para o registro de manipuladores de eventos para eventos do componente.
public interface class IEventBindingServicepublic interface IEventBindingService[System.Runtime.InteropServices.ComVisible(true)]
public interface IEventBindingServicetype IEventBindingService = interface[<System.Runtime.InteropServices.ComVisible(true)>]
type IEventBindingService = interfacePublic Interface IEventBindingService- Derivado
- Atributos
Exemplos
O exemplo a seguir demonstra um designer que usa o para vincular o IEventBindingService evento de um componente com um manipulador de eventos em tempo de design quando o comando de menu de atalho personalizado que o designer adiciona para o componente é invocado. Para usar o exemplo, compile-o em uma biblioteca de classes, adicione uma referência de um projeto Windows Forms, adicione o componente na biblioteca de classes à Caixa de Ferramentas clicando com o botão direito do mouse na Caixa de Ferramentas e selecionando Personalizar Caixa de Ferramentas, escolhendo a biblioteca de classes e clicando em OK e adicione uma instância do EventControl a um Formulário. Em seguida, clique com o botão direito do mouse no EventControl e clique no comando de menu de atalho Conectar testEvent. Um método de manipulador de eventos vazio é criado e o método testEvent do EventControl é inicializado para esse manipulador de eventos no código de inicialização do Formulário.
#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 );
}
};
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.
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);
}
}
}
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 (eventservice IsNot 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
Comentários
O serviço de associação de eventos fornece uma maneira de vincular um manipulador de eventos a um evento de componente do código do designer.
Para vincular um manipulador de eventos a um evento de componente usando o IEventBindingService, primeiro você deve obter um EventDescriptor para o evento do componente que você pretende vincular. O IEventBindingService fornece métodos que podem converter um EventDescriptor em um PropertyDescriptor que você pode usar para configurar o evento com um nome de método do manipulador de eventos.
O TypeDescriptor objeto fornece um GetEvents método que você pode usar para obter um EventDescriptorCollection objeto que EventDescriptor contém para cada evento de um componente. Os GetEventProperty métodos e GetEventProperties do IEventBindingService retornam um PropertyDescriptor para cada EventDescriptor um passado para qualquer método. Cada PropertyDescriptor um retornado de GetEventProperty ou GetEventProperties tem um tipo de propriedade de cadeia de caracteres. Você pode definir essa cadeia de caracteres como um valor que indica o nome do método de manipulador de eventos para vincular o evento ao usando o SetValue método do PropertyDescriptor.
Métodos
| CreateUniqueMethodName(IComponent, EventDescriptor) |
Cria um nome exclusivo para um método do manipulador de eventos para o componente e o evento especificados. |
| GetCompatibleMethods(EventDescriptor) |
Obtém uma coleção de métodos de manipulador de eventos que têm uma assinatura de método compatível com o evento especificado. |
| GetEvent(PropertyDescriptor) |
Obtém um EventDescriptor para o evento que o descritor de propriedade especificado representa, se ele representar um evento. |
| GetEventProperties(EventDescriptorCollection) |
Converte um conjunto de descritores de eventos em um conjunto de descritores de propriedades. |
| GetEventProperty(EventDescriptor) |
Converte um único descritor de eventos em um descritor de propriedades. |
| ShowCode() |
Exibe o código do usuário para o designer. |
| ShowCode(IComponent, EventDescriptor) |
Exibe o código do usuário para o evento especificado. |
| ShowCode(Int32) |
Exibe o código do usuário para o designer na linha especificada. |
Aplica-se a
Confira também
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