Cómo: Personalizar la generación de descripciones de servicio y clases de proxy
Este tema es específico de una tecnología heredada. Ahora, los servicios Web XML y los clientes de servicios Web XML deben crearse con Windows Communication Foundation.
El ejemplo de código siguiente es un SDFE que extiende los procesos de generación del proxy y descripción del servicio para incluir detalles sobre una extensión SOAP de YML.
Ejemplo
Imports System
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.IO
Imports System.Text
Imports System.Web.Services.Configuration
Imports System.Web.Services.Description
Imports System.Xml.Serialization
Imports System.CodeDom
' The YMLAttribute allows a developer to specify that the YML SOAP
' extension run on a per-method basis. The disabled property
' turns reversing the XML on and off.
<AttributeUsage(AttributeTargets.Method, AllowMultiple:=False)> _
Public Class YMLAttribute
Inherits SoapExtensionAttribute
Dim _priority As Integer = 0
Dim _disabled As Boolean = False
Public Sub New()
Me.New(False)
End Sub
Public Sub New(ByVal Disabled As Boolean)
_disabled = Disabled
End Sub
Public Overrides ReadOnly Property ExtensionType() As Type
Get
Return GetType(YMLExtension)
End Get
End Property
Public Overrides Property Priority() As Integer
Get
Return _priority
End Get
Set(ByVal Value As Integer)
_priority = Value
End Set
End Property
Public Property Disabled() As Boolean
Get
Return _disabled
End Get
Set(ByVal Value As Boolean)
_disabled = Value
End Set
End Property
End Class
Public Class YMLExtension
Inherits SoapExtension
Dim _disabled As Boolean = False
Dim oldStream As Stream
Dim newStream As Stream
Public Overloads Overrides Function GetInitializer(ByVal methodInfo _
As LogicalMethodInfo, _
ByVal attribute As SoapExtensionAttribute) As Object
Dim attr As YMLAttribute = attribute
If (Not attr Is Nothing) Then
Return attr.Disabled
End If
Return False
End Function
Public Overloads Overrides Function GetInitializer(ByVal _
WebServiceType As Type) As Object
Return False
End Function
Public Overrides Sub Initialize(ByVal initializer As Object)
If (TypeOf initializer Is Boolean) Then
_disabled = CBool(initializer)
End If
End Sub
Public Overrides Function ChainStream(ByVal streamref As Stream) _
As Stream
If (_disabled) Then
Return CType(Me, SoapExtension).ChainStream(streamref)
End If
oldStream = streamref
newStream = New MemoryStream()
Return newStream
End Function
Public Overrides Sub ProcessMessage(ByVal message As SoapMessage)
If (_disabled) Then Return
Select Case (message.Stage)
Case SoapMessageStage.BeforeSerialize
Encode(message)
Case SoapMessageStage.AfterSerialize
newStream.Position = 0
Reverse(newStream, oldStream)
Case SoapMessageStage.BeforeDeserialize
Decode(message)
Case SoapMessageStage.AfterDeserialize
End Select
End Sub
Sub Encode(ByRef message As SoapMessage)
message.ContentType = "text/yml"
End Sub
Sub Decode(ByVal message As SoapMessage)
If (message.ContentType <> "text/yml") Then
Throw New Exception("invalid content type:" + _
message.ContentType)
End If
Reverse(oldStream, newStream)
newStream.Position = 0
message.ContentType = "text/xml"
End Sub
Sub Reverse(ByVal source As Stream, ByVal dest As Stream)
Dim reader As TextReader = New StreamReader(source)
Dim writer As TextWriter = New StreamWriter(dest)
Dim line As String
line = reader.ReadLine()
While (Not line Is Nothing)
writer.WriteLine(StrReverse(line))
line = reader.ReadLine()
End While
writer.Flush()
End Sub
End Class
' The YMLReflector class is part of the YML SDFE; it is
' called during the service description generation process.
Public Class YMLReflector
Inherits SoapExtensionReflector
Public Overrides Sub ReflectMethod()
Dim reflector As ProtocolReflector = ReflectionContext
Dim attr As YMLAttribute = _
reflector.Method.GetCustomAttribute(GetType(YMLAttribute))
' If the YMLAttribute has been applied to this Web service
' method, adds the XML defined in the YMLOperationBinding class.
If (Not attr Is Nothing) Then
Dim yml As YMLOperationBinding = New YMLOperationBinding()
yml.Reverse = Not attr.Disabled
reflector.OperationBinding.Extensions.Add(yml)
End If
End Sub
End Class
' The YMLImporter class is part of the YML SDFE; it is called when
' a proxy class is generated for each Web service method the proxy
' class communicates with. The class checks whether the service
' description contains the XML that this SDFE adds to a service
' description. If it exists, then the YMLExtension is applied to the
' method in the proxy class.
Public Class YMLImporter
Inherits SoapExtensionImporter
Public Overrides Sub ImportMethod(ByVal metadata As _
CodeAttributeDeclarationCollection)
Dim importer As SoapProtocolImporter = ImportContext
' Checks whether the XML specified in the YMLOperationBinding is
' in the service description.
Dim yml As YMLOperationBinding = _
importer.OperationBinding.Extensions.Find(
GetType(YMLOperationBinding))
If (Not yml Is Nothing) Then
' Only applies the YMLAttribute to the method when the XML
' should be reversed.
If (yml.Reverse) Then
Dim attr As CodeAttributeDeclaration = New _
CodeAttributeDeclaration(GetType(YMLAttribute).FullName)
attr.Arguments.Add(New CodeAttributeArgument(New _
CodePrimitiveExpression(True)))
metadata.Add(attr)
End If
End If
End Sub
End Class
' The YMLOperationBinding class is part of the YML SDFE; it is the
' class that is serialized into XML and placed in the service
' description.
<XmlFormatExtension("action", YMLOperationBinding.YMLNamespace, _
GetType(OperationBinding)), _
XmlFormatExtensionPrefix("yml", YMLOperationBinding.YMLNamespace)> _
Public Class YMLOperationBinding
Inherits ServiceDescriptionFormatExtension
Private _reverse As Boolean
Public Const YMLNamespace As String = "https://www.contoso.com/yml"
<XmlElement("Reverse")> _
Public Property Reverse() As Boolean
Get
Return _reverse
End Get
Set(ByVal Value As Boolean)
_reverse = Value
End Set
End Property
End Class
using System;
using System.CodeDom;
using System.IO;
using System.Text;
using System.Web.Services.Configuration;
using System.Web.Services.Description;
using System.Web.Services.Protocols;
using System.Xml.Serialization;
// The YMLAttribute allows a developer to specify that the YML SOAP
// extension run on a per-method basis. The disabled property
// turns reversing the XML on and off.
[AttributeUsage(AttributeTargets.Method, AllowMultiple=false)]
public class YMLAttribute : SoapExtensionAttribute
{
int priority = 0;
bool disabled = false;
public YMLAttribute() : this(false) {}
public YMLAttribute(bool disabled)
{
this.disabled = disabled;
}
public override Type ExtensionType
{
get { return typeof(YMLExtension); }
}
public override int Priority
{
get { return priority; }
set { priority = value; }
}
public bool Disabled
{
get { return disabled; }
set { disabled = value; }
}
}
public class YMLExtension : SoapExtension
{
bool disabled = false;
Stream oldStream;
Stream newStream;
public override object GetInitializer(LogicalMethodInfo methodInfo,
SoapExtensionAttribute attribute)
{
YMLAttribute attr = attribute as YMLAttribute;
if (attr != null) return attr.Disabled;
return false;
}
public override object GetInitializer(Type serviceType)
{
return false;
}
public override void Initialize(object initializer)
{
if (initializer is Boolean) disabled = (bool)initializer;
}
public override Stream ChainStream(Stream stream)
{
if (disabled) return base.ChainStream(stream);
oldStream = stream;
newStream = new MemoryStream();
return newStream;
}
public override void ProcessMessage(SoapMessage message)
{
if (disabled) return;
switch (message.Stage)
{
case SoapMessageStage.BeforeSerialize:
Encode(message);
break;
case SoapMessageStage.AfterSerialize:
newStream.Position = 0;
Reverse(newStream, oldStream);
break;
case SoapMessageStage.BeforeDeserialize:
Decode(message);
break;
case SoapMessageStage.AfterDeserialize:
break;
}
}
void Encode(SoapMessage message)
{
message.ContentType = "text/yml";
}
void Decode(SoapMessage message)
{
if (message.ContentType != "text/yml")
throw new Exception("invalid content type:" + message.ContentType);
Reverse(oldStream, newStream);
newStream.Position = 0;
message.ContentType = "text/xml";
}
void Reverse(Stream from, Stream to)
{
TextReader reader = new StreamReader(from);
TextWriter writer = new StreamWriter(to);
string line;
while ((line = reader.ReadLine()) != null)
{
StringBuilder builder = new StringBuilder();
for (int i = line.Length - 1; i >= 0; i--)
{
builder.Append(line[i]);
}
writer.WriteLine(builder.ToString());
}
writer.Flush();
}
}
// The YMLReflector class is part of the YML SDFE; it is
// called during the service description generation process.
public class YMLReflector : SoapExtensionReflector
{
public override void ReflectMethod()
{
ProtocolReflector reflector = ReflectionContext;
YMLAttribute attr = (YMLAttribute)reflector.Method.GetCustomAttribute(
typeof(YMLAttribute));
// If the YMLAttribute has been applied to this Web service
// method, adds the XML defined in the YMLOperationBinding class.
if (attr != null)
{
YMLOperationBinding yml = new YMLOperationBinding();
yml.Reverse = !(attr.Disabled);
reflector.OperationBinding.Extensions.Add(yml);
}
}
}
// The YMLImporter class is part of the YML SDFE; it is called when
// a proxy class is generated for each Web service method the proxy
// class communicates with. The class checks whether the service
// description contains the XML that this SDFE adds to a service
// description. If it exists, then the YMLExtension is applied to the
// method in the proxy class.
public class YMLImporter : SoapExtensionImporter
{
public override void ImportMethod(CodeAttributeDeclarationCollection
metadata)
{
SoapProtocolImporter importer = ImportContext;
// Checks whether the XML specified in the YMLOperationBinding is in
// the service description.
YMLOperationBinding yml = (YMLOperationBinding)
importer.OperationBinding.Extensions.Find(
typeof(YMLOperationBinding));
if (yml != null)
{
// Only applies the YMLAttribute to the method when the XML should
// be reversed.
if (yml.Reverse)
{
CodeAttributeDeclaration attr = new CodeAttributeDeclaration(
typeof(YMLAttribute).FullName);
attr.Arguments.Add(new CodeAttributeArgument(new
CodePrimitiveExpression(true)));
metadata.Add(attr);
}
}
}
}
// The YMLOperationBinding class is part of the YML SDFE; it is the
// class that is serialized into XML and placed in the service
// description.
[XmlFormatExtension("action", YMLOperationBinding.YMLNamespace,
typeof(OperationBinding))]
[XmlFormatExtensionPrefix("yml", YMLOperationBinding.YMLNamespace)]
public class YMLOperationBinding : ServiceDescriptionFormatExtension
{
private Boolean reverse;
public const string YMLNamespace = "https://www.contoso.com/yml";
[XmlElement("Reverse")]
public Boolean Reverse
{
get { return reverse; }
set { reverse = value; }
}
}
Vea también
Tareas
Tutorial: Personalizar la generación de descripciones de servicio y clases de proxy
Referencia
XmlFormatExtensionAttribute
XmlFormatExtensionPrefixAttribute
XmlFormatExtensionPointAttribute