(VB.NET UWP/WinRT) HTTP Request Boundary Property

Explains and demonstrates the HTTP request Boundary property. For multipart HTTP requests, Chilkat auto-generates a boundary string when the Boundary property is left unset (or empty). For example:

POST /something HTTP/1.1
Content-Type: multipart/form-data; boundary=------------090207000006060206010508
Host: domain
Content-Length: 378

--------------090207000006060206010508
Content-Disposition: form-data; name="fileA"; filename="fileA.txt"
Content-Type: text/plain

This is the contents of file A
--------------090207000006060206010508
Content-Disposition: form-data; name="fileB"; filename="fileB.txt"
Content-Type: text/plain

This is the contents of file B
--------------090207000006060206010508--

POST /something HTTP/1.1
Content-Type: multipart/form-data; boundary=ABC123HELLOWORLD
Host: domain
Content-Length: 318

--ABC123HELLOWORLD
Content-Disposition: form-data; name="fileA"; filename="fileA.txt"
Content-Type: text/plain

This is the contents of file A
--ABC123HELLOWORLD
Content-Disposition: form-data; name="fileB"; filename="fileB.txt"
Content-Type: text/plain

This is the contents of file B
--ABC123HELLOWORLD--

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

Dim req As New Chilkat.HttpRequest

req.HttpVerb = "POST"
req.Path = "/something"
req.ContentType = "multipart/form-data"

req.AddStringForUpload("fileA","fileA.txt","This is the contents of file A","utf-8")
req.AddStringForUpload("fileB","fileB.txt","This is the contents of file B","utf-8")

' When the Boundary property is empty (has not yet been set)
' Chilkat auto-generates a random boundary for the request.
' This should almost always be sufficient.
' For example, one can see the generated boundary here:
Debug.WriteLine(req.GenerateRequestText())

' If the Boundary property is set to a specific string, then the
' request will use it:
req.Boundary = "ABC123HELLOWORLD"
Debug.WriteLine(req.GenerateRequestText())