.NET Framework Class Library Attachment Class Represents an attachment to an e-mail.

Inheritance Hierarchy
Namespace:
System.Net.Mail
Assembly:
System (in System.dll)

Syntax
Public Class Attachment _
Inherits AttachmentBase
public class Attachment : AttachmentBase
public ref class Attachment : public AttachmentBase
type Attachment =
class
inherit AttachmentBase
end
The Attachment type exposes the following members.

Constructors

Properties

Methods
|
| Name | Description |
|---|
.gif) .gif) | CreateAttachmentFromString(String, ContentType) | Creates a mail attachment using the content from the specified string, and the specified ContentType. | .gif) .gif) | CreateAttachmentFromString(String, String) | Creates a mail attachment using the content from the specified string, and the specified MIME content type name. | .gif) .gif) | CreateAttachmentFromString(String, String, Encoding, String) | Creates a mail attachment using the content from the specified string, the specified MIME content type name, character encoding, and MIME header information for the attachment. | .gif) | Dispose()()() | Releases the resources used by the AttachmentBase. (Inherited from AttachmentBase.) | .gif) | Dispose(Boolean) | Releases the unmanaged resources used by the AttachmentBase and optionally releases the managed resources. (Inherited from AttachmentBase.) | .gif) | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) | .gif) | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) | .gif) | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) | .gif) | GetType | Gets the Type of the current instance. (Inherited from Object.) | .gif) | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) | .gif) | ToString | Returns a string that represents the current object. (Inherited from Object.) | Top

Remarks
The Attachment class is used with the MailMessage class. All messages include a Body, which contains the content of the message. In addition to the body, you might want to send additional files. These are sent as attachments and are represented as Attachment instances. To add an attachment to a mail message, add it to the MailMessage..::.Attachments collection. Attachment content can be a String, Stream, or file name. You can specify the content in an attachment by using any of the Attachment constructors. The MIME Content-Type header information for the attachment is represented by the ContentType property. The Content-Type header specifies the media type and subtype and any associated parameters. Use ContentType to get the instance associated with an attachment. The MIME Content-Disposition header is represented by the ContentDisposition property. The Content-Disposition header specifies the presentation and file time stamps for an attachment. A Content-Disposition header is sent only if the attachment is a file. Use the ContentDisposition property to get the instance associated with an attachment. The MIME Content-Transfer-Encoding header is represented by the TransferEncoding property.

Examples
The following code example demonstrates attaching a file to an e-mail message.
public static void CreateMessageWithAttachment(string server)
{
// Specify the file to be attached and sent.
// This example assumes that a file named Data.xls exists in the
// current working directory.
string file = "data.xls";
// Create a message and set up the recipients.
MailMessage message = new MailMessage(
"jane@contoso.com",
"ben@contoso.com",
"Quarterly data report.",
"See the attached spreadsheet.");
// Create the file attachment for this e-mail message.
Attachment data = new Attachment(file, MediaTypeNames.Application.Octet);
// Add time stamp information for the file.
ContentDisposition disposition = data.ContentDisposition;
disposition.CreationDate = System.IO.File.GetCreationTime(file);
disposition.ModificationDate = System.IO.File.GetLastWriteTime(file);
disposition.ReadDate = System.IO.File.GetLastAccessTime(file);
// Add the file attachment to this e-mail message.
message.Attachments.Add(data);
//Send the message.
SmtpClient client = new SmtpClient(server);
// Add credentials if the SMTP server requires them.
client.Credentials = CredentialCache.DefaultNetworkCredentials;
try {
client.Send(message);
}
catch (Exception ex) {
Console.WriteLine("Exception caught in CreateMessageWithAttachment(): {0}",
ex.ToString() );
}
// Display the values in the ContentDisposition for the attachment.
ContentDisposition cd = data.ContentDisposition;
Console.WriteLine("Content disposition");
Console.WriteLine(cd.ToString());
Console.WriteLine("File {0}", cd.FileName);
Console.WriteLine("Size {0}", cd.Size);
Console.WriteLine("Creation {0}", cd.CreationDate);
Console.WriteLine("Modification {0}", cd.ModificationDate);
Console.WriteLine("Read {0}", cd.ReadDate);
Console.WriteLine("Inline {0}", cd.Inline);
Console.WriteLine("Parameters: {0}", cd.Parameters.Count);
foreach (DictionaryEntry d in cd.Parameters)
{
Console.WriteLine("{0} = {1}", d.Key, d.Value);
}
data.Dispose();
}
static void CreateMessageWithAttachment( String^ server )
{
// Specify the file to be attached and sent.
// This example assumes that a file named Data.xls exists in the
// current working directory.
String^ file = L"data.xls";
// Create a message and set up the recipients.
MailMessage^ message = gcnew MailMessage( L"jane@contoso.com",L"ben@contoso.com",L"Quarterly data report.",L"See the attached spreadsheet." );
// Create the file attachment for this e-mail message.
Attachment^ data = gcnew Attachment(file, MediaTypeNames::Application::Octet);
// Add time stamp information for the file.
ContentDisposition^ disposition = data->ContentDisposition;
disposition->CreationDate = System::IO::File::GetCreationTime( file );
disposition->ModificationDate = System::IO::File::GetLastWriteTime( file );
disposition->ReadDate = System::IO::File::GetLastAccessTime( file );
// Add the file attachment to this e-mail message.
message->Attachments->Add( data );
//Send the message.
SmtpClient^ client = gcnew SmtpClient( server );
// Add credentials if the SMTP server requires them.
client->Credentials = CredentialCache::DefaultNetworkCredentials;
client->Send( message );
// Display the values in the ContentDisposition for the attachment.
ContentDisposition^ cd = data->ContentDisposition;
Console::WriteLine( L"Content disposition" );
Console::WriteLine( cd );
Console::WriteLine( L"File {0}", cd->FileName );
Console::WriteLine( L"Size {0}", cd->Size );
Console::WriteLine( L"Creation {0}", cd->CreationDate );
Console::WriteLine( L"Modification {0}", cd->ModificationDate );
Console::WriteLine( L"Read {0}", cd->ReadDate );
Console::WriteLine( L"Inline {0}", cd->Inline );
Console::WriteLine( L"Parameters: {0}", cd->Parameters->Count );
IEnumerator^ myEnum1 = cd->Parameters->GetEnumerator();
while ( myEnum1->MoveNext() )
{
DictionaryEntry^ d = safe_cast<DictionaryEntry^>(myEnum1->Current);
Console::WriteLine( L"{0} = {1}", d->Key, d->Value );
}
data->~Attachment();
client->~SmtpClient();
}

Version Information
.NET FrameworkSupported in: 4, 3.5, 3.0, 2.0 .NET Framework Client ProfileSupported in: 4, 3.5 SP1

Platforms
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role not supported), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Thread Safety
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also
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Biblioteca de clases de .NET Framework Attachment (Clase) Representa los datos adjuntos a un mensaje de correo electrónico.

Jerarquía de herencia
Espacio de nombres:
System.Net.Mail
Ensamblado:
System (en System.dll)

Sintaxis
Public Class Attachment _
Inherits AttachmentBase
public class Attachment : AttachmentBase
public ref class Attachment : public AttachmentBase
type Attachment =
class
inherit AttachmentBase
end
El tipo Attachment expone los siguientes miembros.

Constructores

Propiedades

Métodos

Comentarios
La clase Attachment se utiliza junto con la clase MailMessage. Todos los mensajes contienen un cuerpo (Body), donde se incluye el contenido del mensaje. Además del cuerpo, es posible que se deseen enviar archivos adicionales. Estos archivos se envían en forma de datos adjuntos y se representan en forma de instancias de Attachment. Para agregar datos adjuntos a un mensaje de correo, agregue estos datos a la colección MailMessage..::.Attachments. El contenido de los datos adjuntos puede ser un objeto String, Stream o un nombre de archivo. Puede especificar el contenido de los datos adjuntos utilizando cualquiera de los constructores Attachment. La propiedad ContentType representa la información del encabezado Content-Type MIME de los datos adjuntos. El encabezado Content-Type especifica el tipo de medio y el subtipo, y cualquier parámetro asociado. Utilice ContentType para obtener la instancia asociada a los datos adjuntos. La propiedad ContentDisposition representa el encabezado Content-Disposition MIME. El encabezado Content-Disposition especifica la presentación y las marcas de tiempo de archivo de los datos adjuntos. Un encabezado Content-Disposition sólo se envía si los datos adjuntos son un archivo. Utilice la propiedad ContentDisposition para obtener la instancia asociada a los datos adjuntos. La propiedad TransferEncoding representa el encabezado Content-Transfer-Encoding MIME.

Ejemplos
En el siguiente ejemplo de código se muestra la forma de adjuntar un archivo a un mensaje de correo electrónico.
public static void CreateMessageWithAttachment(string server)
{
// Specify the file to be attached and sent.
// This example assumes that a file named Data.xls exists in the
// current working directory.
string file = "data.xls";
// Create a message and set up the recipients.
MailMessage message = new MailMessage(
"jane@contoso.com",
"ben@contoso.com",
"Quarterly data report.",
"See the attached spreadsheet.");
// Create the file attachment for this e-mail message.
Attachment data = new Attachment(file, MediaTypeNames.Application.Octet);
// Add time stamp information for the file.
ContentDisposition disposition = data.ContentDisposition;
disposition.CreationDate = System.IO.File.GetCreationTime(file);
disposition.ModificationDate = System.IO.File.GetLastWriteTime(file);
disposition.ReadDate = System.IO.File.GetLastAccessTime(file);
// Add the file attachment to this e-mail message.
message.Attachments.Add(data);
//Send the message.
SmtpClient client = new SmtpClient(server);
// Add credentials if the SMTP server requires them.
client.Credentials = CredentialCache.DefaultNetworkCredentials;
try {
client.Send(message);
}
catch (Exception ex) {
Console.WriteLine("Exception caught in CreateMessageWithAttachment(): {0}",
ex.ToString() );
}
// Display the values in the ContentDisposition for the attachment.
ContentDisposition cd = data.ContentDisposition;
Console.WriteLine("Content disposition");
Console.WriteLine(cd.ToString());
Console.WriteLine("File {0}", cd.FileName);
Console.WriteLine("Size {0}", cd.Size);
Console.WriteLine("Creation {0}", cd.CreationDate);
Console.WriteLine("Modification {0}", cd.ModificationDate);
Console.WriteLine("Read {0}", cd.ReadDate);
Console.WriteLine("Inline {0}", cd.Inline);
Console.WriteLine("Parameters: {0}", cd.Parameters.Count);
foreach (DictionaryEntry d in cd.Parameters)
{
Console.WriteLine("{0} = {1}", d.Key, d.Value);
}
data.Dispose();
}
static void CreateMessageWithAttachment( String^ server )
{
// Specify the file to be attached and sent.
// This example assumes that a file named Data.xls exists in the
// current working directory.
String^ file = L"data.xls";
// Create a message and set up the recipients.
MailMessage^ message = gcnew MailMessage( L"jane@contoso.com",L"ben@contoso.com",L"Quarterly data report.",L"See the attached spreadsheet." );
// Create the file attachment for this e-mail message.
Attachment^ data = gcnew Attachment(file, MediaTypeNames::Application::Octet);
// Add time stamp information for the file.
ContentDisposition^ disposition = data->ContentDisposition;
disposition->CreationDate = System::IO::File::GetCreationTime( file );
disposition->ModificationDate = System::IO::File::GetLastWriteTime( file );
disposition->ReadDate = System::IO::File::GetLastAccessTime( file );
// Add the file attachment to this e-mail message.
message->Attachments->Add( data );
//Send the message.
SmtpClient^ client = gcnew SmtpClient( server );
// Add credentials if the SMTP server requires them.
client->Credentials = CredentialCache::DefaultNetworkCredentials;
client->Send( message );
// Display the values in the ContentDisposition for the attachment.
ContentDisposition^ cd = data->ContentDisposition;
Console::WriteLine( L"Content disposition" );
Console::WriteLine( cd );
Console::WriteLine( L"File {0}", cd->FileName );
Console::WriteLine( L"Size {0}", cd->Size );
Console::WriteLine( L"Creation {0}", cd->CreationDate );
Console::WriteLine( L"Modification {0}", cd->ModificationDate );
Console::WriteLine( L"Read {0}", cd->ReadDate );
Console::WriteLine( L"Inline {0}", cd->Inline );
Console::WriteLine( L"Parameters: {0}", cd->Parameters->Count );
IEnumerator^ myEnum1 = cd->Parameters->GetEnumerator();
while ( myEnum1->MoveNext() )
{
DictionaryEntry^ d = safe_cast<DictionaryEntry^>(myEnum1->Current);
Console::WriteLine( L"{0} = {1}", d->Key, d->Value );
}
data->~Attachment();
client->~SmtpClient();
}

Información de versión
.NET FrameworkCompatible con: 4, 3.5, 3.0, 2.0 .NET Framework Client ProfileCompatible con: 4, 3.5 SP1

Plataformas
Windows 7, Windows Vista SP1 o posterior, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (no se admite Server Core), Windows Server 2008 R2 (se admite Server Core con SP1 o posterior), Windows Server 2003 SP2
.NET Framework no admite todas las versiones de todas las plataformas. Para obtener una lista de las versiones compatibles, vea Requisitos de sistema de .NET Framework.

Seguridad para subprocesos
Todos los miembros static ( Shared en Visual Basic) públicos de este tipo son seguros para la ejecución de subprocesos. No se garantiza que los miembros de instancias sean seguros para la ejecución de subprocesos.

Vea también
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