(VB.NET UWP/WinRT) Parse MIME Header Fields

Demonstrates how to parse MIME header fields, including Content-Type, Content-Disposition, and Content-Transfer-Encoding.

This example uses a MIME test file located at http://www.chilkatsoft.com/testData/sampleMime2.txt. It contains the following MIME:

Content-Type: multipart/mixed;
 boundary="------------080707010302060306060800";

This is a multi-part message in MIME format.

--------------080707010302060306060800
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

This is the plain-text body.
--------------080707010302060306060800
Content-Disposition: attachment; filename="starfish.gif";
Content-Transfer-Encoding: base64
Content-Type: image/gif; name="starfish.gif";

R0lGODlhIAAgAPcAAP///+/v7/f39+/n5/fv7//39/fn597OzufW1tbGxs69vffe3u/W1salpZQQ
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--------------080707010302060306060800--

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim mime As New Chilkat.Mime

' Load the sampleMime2.txt file into the MIME object.
' (This file is available at http://www.chilkatsoft.com/testData/sampleMime2.txt )

Dim success As Boolean = mime.LoadMimeFile("sampleMime2.txt")
If (success = False) Then
    Debug.WriteLine(mime.LastErrorText)
    Exit Sub
End If


' The GIF image is the 2nd sub-part located directly under the
' top-level MIME node.  Indexing begins at 0, therefore the 2nd
' sub-part is at index 1.
Dim part2 As Chilkat.Mime
part2 = mime.GetPart(1)

' -------------------------------
' Content-Disposition
' -------------------------------
' In this example, the Content-Disposition header field
' contains this value:
' attachment; filename="starfish.gif"

' To get the "filename", call GetHeaderFieldAttribute
' Header field names and attribute names are case insensitive.
Dim filename As String = part2.GetHeaderFieldAttribute("Content-Disposition","filename")
Debug.WriteLine("Filename: " & filename)

' Because the "filename" is so often accessed, it is also available
' by accessing the "Filename" property:
Debug.WriteLine("Filename: " & part2.Filename)

' The disposition (without attributes) which in this case 
' is the string "attachment" is accessed via the Disposition property:
Debug.WriteLine("Disposition: " & part2.Disposition)

' To get the full value of the Content-Disposition header field,
' call GetHeaderField.
Debug.WriteLine("Content-Disposition: " & part2.GetHeaderField("Content-Disposition"))

' -------------------------------
' Content-Type
' -------------------------------
' In this example, the Content-Type header field
' contains this value:
' image/gif; name="starfish.gif"

' To get the "name", call GetHeaderFieldAttribute
Dim name As String = part2.GetHeaderFieldAttribute("Content-Type","name")
Debug.WriteLine("Content-Type name: " & name)

' Because the "name" is so often accessed, it is also available
' by accessing the "Name" property:
Debug.WriteLine("Content-Type name: " & part2.Name)

' The content-type without attributes is available in the
' ContentType property:
Debug.WriteLine("Content-Type: " & part2.ContentType)

' To get the full value of the Content-Type header field,
' call GetHeaderField.
Debug.WriteLine("Content-Type: " & part2.GetHeaderField("Content-Type"))

' -------------------------------
' Content-Transfer-Encoding
' -------------------------------

' The Encoding property contains the value of the
' Content-Transfer-Encoding property. 
' Calling GetHeaderField("Content-Transfer-Encoding") is
' equivalent to accessing the Encoding property:
Debug.WriteLine("Content-Transfer-Encoding: " & part2.Encoding)
Debug.WriteLine("Content-Transfer-Encoding: " & part2.GetHeaderField("Content-Transfer-Encoding"))



Debug.WriteLine("Finished.")