(VB.NET) Add Data to multipart/form-data Request

Demonstrates how to add content (such as a JPG, PDF, XML, etc.) to multipart/form-data requests.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim req As New Chilkat.HttpRequest
req.HttpVerb = "POST"
req.ContentType = "multipart/form-data"
req.Path = "/xyz/something"

req.AddParam("param1","value1")
req.AddParam("param2","value2")

' Add some small files to the request. (Small so we can see what the full request looks like without too much data..)
Dim bd As New Chilkat.BinData
Dim success As Boolean = bd.LoadFile("qa_data/jpg/starfish20.jpg")
req.AddBdForUpload("starfish20","starfish20.jpg",bd,"image/jpeg")

success = bd.LoadFile("qa_data/pdf/helloWorld.pdf")
req.AddBdForUpload("helloWorld","helloWorld.pdf",bd,"application/pdf")

success = bd.LoadFile("qa_data/xml/tinyA.xml")
req.AddBdForUpload("tinyA","tinyA.xml",bd,"text/xml")

' This HTTP request contains binary data, so we cannot call GenerateRequestText
' to examine it as a string.  We can instead call GenerateRequestFile
' to write the request to a file and then examine using a hex editor,
' or an editor that is capable of handling null bytes and non-printable chars (perhaps by displaying "?" chars instead).
req.GenerateRequestFile("qa_output/multipartFormDataRequest.bin")


Debug.WriteLine("OK.")

' This is the HTTP multipart/form-data request built by the above code:

' POST /xyz/something HTTP/1.1
' Host: domain
' Content-Type: multipart/form-data; boundary=------------090708030009010000030901
' Content-Length: 2220
' 
' --------------090708030009010000030901
' Content-Disposition: form-data; name="param1"
' 
' value1
' --------------090708030009010000030901
' Content-Disposition: form-data; name="param2"
' 
' value2
' --------------090708030009010000030901
' Content-Disposition: form-data; name="starfish20"; filename="starfish20.jpg"
' Content-Type: image/jpeg
' 
' JPEG DATA HERE...
' --------------090708030009010000030901
' Content-Disposition: form-data; name="helloWorld"; filename="helloWorld.pdf"
' Content-Type: application/pdf
' 
' PDF DATA HERE...
' --------------090708030009010000030901
' Content-Disposition: form-data; name="tinyA"; filename="tinyA.xml"
' Content-Type: text/xml
' 
' XML DATA HERE...
' --------------090708030009010000030901--
'