IInstanceProvider.GetInstance Método
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Devuelve un objeto de servicio.
Sobrecargas
GetInstance(InstanceContext) |
Devuelve un objeto de servicio dado el objeto InstanceContext especificado. |
GetInstance(InstanceContext, Message) |
Devuelve un objeto de servicio dado el objeto InstanceContext especificado. |
GetInstance(InstanceContext)
Devuelve un objeto de servicio dado el objeto InstanceContext especificado.
public:
System::Object ^ GetInstance(System::ServiceModel::InstanceContext ^ instanceContext);
public object GetInstance (System.ServiceModel.InstanceContext instanceContext);
abstract member GetInstance : System.ServiceModel.InstanceContext -> obj
Public Function GetInstance (instanceContext As InstanceContext) As Object
Parámetros
- instanceContext
- InstanceContext
Objeto InstanceContext actual.
Devoluciones
Un objeto de servicio definido por el usuario.
Ejemplos
El ejemplo de código siguiente muestra como implementar IInstanceProvider, que proporciona un comportamiento "singleton"; siempre devuelve la misma instancia del servicio y no la recicla.
public class ObjectProviderBehavior : IInstanceProvider
{
string message;
SampleService service = null;
public ObjectProviderBehavior(string msg)
{
Console.WriteLine("The non-default constructor has been called.");
this.message = msg;
this.service = new SampleService("Singleton sample service.");
}
#region IInstanceProvider Members
public object GetInstance(InstanceContext instanceContext, System.ServiceModel.Channels.Message message)
{
Console.WriteLine("GetInstance is called:");
return this.service;
}
public object GetInstance(InstanceContext instanceContext)
{
Console.WriteLine("GetInstance is called:");
return this.service;
}
public void ReleaseInstance(InstanceContext instanceContext, object instance)
{
Console.WriteLine("ReleaseInstance is called. The SingletonBehaviorAttribute never releases.");
}
#endregion
}
Public Class ObjectProviderBehavior
Implements IInstanceProvider
Private message As String
Private service As SampleService = Nothing
Public Sub New(ByVal msg As String)
Console.WriteLine("The non-default constructor has been called.")
Me.message = msg
Me.service = New SampleService("Singleton sample service.")
End Sub
#Region "IInstanceProvider Members"
Public Function GetInstance(ByVal instanceContext As InstanceContext, ByVal message As System.ServiceModel.Channels.Message) As Object Implements IInstanceProvider.GetInstance
Console.WriteLine("GetInstance is called:")
Return Me.service
End Function
Public Function GetInstance(ByVal instanceContext As InstanceContext) As Object Implements IInstanceProvider.GetInstance
Console.WriteLine("GetInstance is called:")
Return Me.service
End Function
Public Sub ReleaseInstance(ByVal instanceContext As InstanceContext, ByVal instance As Object) Implements IInstanceProvider.ReleaseInstance
Console.WriteLine("ReleaseInstance is called. The SingletonBehaviorAttribute never releases.")
End Sub
#End Region
End Class
El ejemplo de código siguiente muestra cómo implementar un atributo personalizado que implementa IContractBehavior para insertar el proveedor de instancias del servicio personalizado. También implementa IContractBehaviorAttribute, que enlaza su uso a un contrato específico.
public class SingletonBehaviorAttribute : Attribute, IContractBehaviorAttribute, IContractBehavior
{
#region IContractBehaviorAttribute Members
public Type TargetContract
{
get { return typeof(ISampleService); }
}
#endregion
#region IContractBehavior Members
public void AddBindingParameters(ContractDescription description, ServiceEndpoint endpoint, System.ServiceModel.Channels.BindingParameterCollection parameters)
{
return;
}
public void ApplyClientBehavior(ContractDescription description, ServiceEndpoint endpoint, ClientRuntime clientRuntime)
{
return;
}
public void ApplyDispatchBehavior(ContractDescription description, ServiceEndpoint endpoint, DispatchRuntime dispatch)
{
dispatch.InstanceProvider = new ObjectProviderBehavior("Custom ObjectProviderBehavior constructor.");
}
public void Validate(ContractDescription description, ServiceEndpoint endpoint)
{
return;
}
#endregion
}
Public Class SingletonBehaviorAttribute
Inherits Attribute
Implements IContractBehaviorAttribute, IContractBehavior
#Region "IContractBehaviorAttribute Members"
Public ReadOnly Property TargetContract() As Type Implements IContractBehaviorAttribute.TargetContract
Get
Return GetType(ISampleService)
End Get
End Property
#End Region
#Region "IContractBehavior Members"
Public Sub AddBindingParameters(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal parameters As System.ServiceModel.Channels.BindingParameterCollection) Implements IContractBehavior.AddBindingParameters
Return
End Sub
Public Sub ApplyClientBehavior(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal clientRuntime As ClientRuntime) Implements IContractBehavior.ApplyClientBehavior
Return
End Sub
Public Sub ApplyDispatchBehavior(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal dispatch As DispatchRuntime) Implements IContractBehavior.ApplyDispatchBehavior
dispatch.InstanceProvider = New ObjectProviderBehavior("Custom ObjectProviderBehavior constructor.")
End Sub
Public Sub Validate(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint) Implements IContractBehavior.Validate
Return
End Sub
#End Region
End Class
Comentarios
Use el GetInstance(InstanceContext) método para controlar el objeto de servicio exacto que recibe un servicio WCF cuando intenta crear uno nuevo.
Se aplica a
GetInstance(InstanceContext, Message)
Devuelve un objeto de servicio dado el objeto InstanceContext especificado.
public:
System::Object ^ GetInstance(System::ServiceModel::InstanceContext ^ instanceContext, System::ServiceModel::Channels::Message ^ message);
public object GetInstance (System.ServiceModel.InstanceContext instanceContext, System.ServiceModel.Channels.Message message);
abstract member GetInstance : System.ServiceModel.InstanceContext * System.ServiceModel.Channels.Message -> obj
Public Function GetInstance (instanceContext As InstanceContext, message As Message) As Object
Parámetros
- instanceContext
- InstanceContext
Objeto InstanceContext actual.
- message
- Message
El mensaje que activó la creación de un objeto de servicio.
Devoluciones
El objeto de servicio.
Ejemplos
El ejemplo de código siguiente muestra como implementar IInstanceProvider, que proporciona un comportamiento "singleton"; siempre devuelve la misma instancia del servicio y no la recicla.
public class ObjectProviderBehavior : IInstanceProvider
{
string message;
SampleService service = null;
public ObjectProviderBehavior(string msg)
{
Console.WriteLine("The non-default constructor has been called.");
this.message = msg;
this.service = new SampleService("Singleton sample service.");
}
#region IInstanceProvider Members
public object GetInstance(InstanceContext instanceContext, System.ServiceModel.Channels.Message message)
{
Console.WriteLine("GetInstance is called:");
return this.service;
}
public object GetInstance(InstanceContext instanceContext)
{
Console.WriteLine("GetInstance is called:");
return this.service;
}
public void ReleaseInstance(InstanceContext instanceContext, object instance)
{
Console.WriteLine("ReleaseInstance is called. The SingletonBehaviorAttribute never releases.");
}
#endregion
}
Public Class ObjectProviderBehavior
Implements IInstanceProvider
Private message As String
Private service As SampleService = Nothing
Public Sub New(ByVal msg As String)
Console.WriteLine("The non-default constructor has been called.")
Me.message = msg
Me.service = New SampleService("Singleton sample service.")
End Sub
#Region "IInstanceProvider Members"
Public Function GetInstance(ByVal instanceContext As InstanceContext, ByVal message As System.ServiceModel.Channels.Message) As Object Implements IInstanceProvider.GetInstance
Console.WriteLine("GetInstance is called:")
Return Me.service
End Function
Public Function GetInstance(ByVal instanceContext As InstanceContext) As Object Implements IInstanceProvider.GetInstance
Console.WriteLine("GetInstance is called:")
Return Me.service
End Function
Public Sub ReleaseInstance(ByVal instanceContext As InstanceContext, ByVal instance As Object) Implements IInstanceProvider.ReleaseInstance
Console.WriteLine("ReleaseInstance is called. The SingletonBehaviorAttribute never releases.")
End Sub
#End Region
End Class
El ejemplo de código siguiente muestra cómo implementar un atributo personalizado que implementa IContractBehavior para insertar el proveedor de instancias del servicio personalizado. También implementa IContractBehaviorAttribute, que enlaza su uso a un contrato específico.
public class SingletonBehaviorAttribute : Attribute, IContractBehaviorAttribute, IContractBehavior
{
#region IContractBehaviorAttribute Members
public Type TargetContract
{
get { return typeof(ISampleService); }
}
#endregion
#region IContractBehavior Members
public void AddBindingParameters(ContractDescription description, ServiceEndpoint endpoint, System.ServiceModel.Channels.BindingParameterCollection parameters)
{
return;
}
public void ApplyClientBehavior(ContractDescription description, ServiceEndpoint endpoint, ClientRuntime clientRuntime)
{
return;
}
public void ApplyDispatchBehavior(ContractDescription description, ServiceEndpoint endpoint, DispatchRuntime dispatch)
{
dispatch.InstanceProvider = new ObjectProviderBehavior("Custom ObjectProviderBehavior constructor.");
}
public void Validate(ContractDescription description, ServiceEndpoint endpoint)
{
return;
}
#endregion
}
Public Class SingletonBehaviorAttribute
Inherits Attribute
Implements IContractBehaviorAttribute, IContractBehavior
#Region "IContractBehaviorAttribute Members"
Public ReadOnly Property TargetContract() As Type Implements IContractBehaviorAttribute.TargetContract
Get
Return GetType(ISampleService)
End Get
End Property
#End Region
#Region "IContractBehavior Members"
Public Sub AddBindingParameters(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal parameters As System.ServiceModel.Channels.BindingParameterCollection) Implements IContractBehavior.AddBindingParameters
Return
End Sub
Public Sub ApplyClientBehavior(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal clientRuntime As ClientRuntime) Implements IContractBehavior.ApplyClientBehavior
Return
End Sub
Public Sub ApplyDispatchBehavior(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint, ByVal dispatch As DispatchRuntime) Implements IContractBehavior.ApplyDispatchBehavior
dispatch.InstanceProvider = New ObjectProviderBehavior("Custom ObjectProviderBehavior constructor.")
End Sub
Public Sub Validate(ByVal description As ContractDescription, ByVal endpoint As ServiceEndpoint) Implements IContractBehavior.Validate
Return
End Sub
#End Region
End Class
Comentarios
Use el GetInstance(InstanceContext, Message) método para controlar el objeto de servicio exacto que recibe un servicio WCF cuando intenta crear uno nuevo.