Attachment Class

Represents an attachment to an e-mail.

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

public class Attachment : AttachmentBase

The Attachment type exposes the following members.

  NameDescription
Public methodAttachment(String)Initializes a new instance of the Attachment class with the specified content string.
Public methodAttachment(Stream, ContentType)Initializes a new instance of the Attachment class with the specified stream and content type.
Public methodAttachment(Stream, String)Initializes a new instance of the Attachment class with the specified stream and name.
Public methodAttachment(String, ContentType)Initializes a new instance of the Attachment class with the specified content string and ContentType.
Public methodAttachment(String, String)Initializes a new instance of the Attachment class with the specified content string and MIME type information.
Public methodAttachment(Stream, String, String)Initializes a new instance of the Attachment class with the specified stream, name, and MIME type information.
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  NameDescription
Public propertyContentDispositionGets the MIME content disposition for this attachment.
Public propertyContentIdGets or sets the MIME content ID for this attachment. (Inherited from AttachmentBase.)
Public propertyContentStreamGets the content stream of this attachment. (Inherited from AttachmentBase.)
Public propertyContentTypeGets the content type of this attachment. (Inherited from AttachmentBase.)
Public propertyNameGets or sets the MIME content type name value in the content type associated with this attachment.
Public propertyNameEncodingSpecifies the encoding for the Attachment Name.
Public propertyTransferEncodingGets or sets the encoding of this attachment. (Inherited from AttachmentBase.)
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  NameDescription
Public methodStatic memberCreateAttachmentFromString(String, ContentType)Creates a mail attachment using the content from the specified string, and the specified ContentType.
Public methodStatic memberCreateAttachmentFromString(String, String)Creates a mail attachment using the content from the specified string, and the specified MIME content type name.
Public methodStatic memberCreateAttachmentFromString(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.
Public methodDispose()Releases the resources used by the AttachmentBase. (Inherited from AttachmentBase.)
Protected methodDispose(Boolean)Releases the unmanaged resources used by the AttachmentBase and optionally releases the managed resources. (Inherited from AttachmentBase.)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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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.

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();
		}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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