.NET Framework Class Library AttachmentCollection Class Stores attachments to be sent as part of an e-mail message.

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

Syntax
Public NotInheritable Class AttachmentCollection _
Inherits Collection(Of Attachment) _
Implements IDisposable
public sealed class AttachmentCollection : Collection<Attachment>,
IDisposable
public ref class AttachmentCollection sealed : public Collection<Attachment^>,
IDisposable
[<Sealed>]
type AttachmentCollection =
class
inherit Collection<Attachment>
interface IDisposable
end
The AttachmentCollection type exposes the following members.

Properties

Methods

Explicit Interface Implementations

Remarks
Instances of the AttachmentCollection class are returned by the MailMessage..::.AlternateViews and MailMessage..::.Attachments properties. Use the AlternateViews property to specify copies of an e-mail message in different formats. For example, if you send a message in HTML, you might also want provide a plain text version in case some of the recipients use e-mail readers that cannot display HTML content. Use the collection returned by the Attachments property to add an attachment, such as a file or the contents of a Stream to this MailMessage.

Examples
The following code example demonstrates how to create and send an e-mail message with an attachment.
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 AttachmentCollection (Clase) Almacena datos adjuntos para que se envíen como parte de un mensaje de correo electrónico.

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

Sintaxis
Public NotInheritable Class AttachmentCollection _
Inherits Collection(Of Attachment) _
Implements IDisposable
public sealed class AttachmentCollection : Collection<Attachment>,
IDisposable
public ref class AttachmentCollection sealed : public Collection<Attachment^>,
IDisposable
[<Sealed>]
type AttachmentCollection =
class
inherit Collection<Attachment>
interface IDisposable
end
El tipo AttachmentCollection expone los siguientes miembros.

Propiedades

Métodos

Implementaciones explícitas de interfaces

Comentarios
Las propiedades MailMessage..::.AlternateViews y MailMessage..::.Attachments devuelven instancias de la clase AttachmentCollection. Utilice la propiedad AlternateViews para especificar distintos formatos para las copias de un mensaje de correo electrónico. Por ejemplo, si envía un mensaje en HTML y algunos de los destinatarios utilizan lectores de correo que no pueden mostrar contenido HTML, es probable que también desee proporcionar una versión de texto sin formato. Utilice la colección devuelta por la propiedad Attachments para agregar datos adjuntos (como un archivo o el contenido de un objeto Stream) a este objeto MailMessage.

Ejemplos
En el siguiente ejemplo de código se muestra la forma de crear y enviar un mensaje de correo electrónico con datos adjuntos.
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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