(VB.NET) HTTP POST JSON

Demonstrates how to send a JSON POST and get the JSON response.

Download: Chilkat .NET Assemblies

Dim req As New Chilkat.HttpRequest()
Dim http As New Chilkat.Http()

Dim success As Boolean

'  Any string unlocks the component for the 1st 30 days.
success = http.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & http.LastErrorText & vbCrLf
    Exit Sub
End If


'  This example duplicates the HTTP POST shown at
'  http://json.org/JSONRequest.html

'  Specifically, the request to be sent looks like this:
'  
POST /request HTTP/1.1
Accept: application/jsonrequest
Content-Encoding: identity
Content-Length: 72
Content-Type: application/jsonrequest
Host: json.penzance.org

{"user":"doctoravatar@penzance.com","forecast":7,"t":"vlIj","zip":94089}


'  First, remove default header fields that would be automatically
'  sent.  (These headers are harmless, and shouldn't need to
'  be suppressed, but just in case...)
http.AcceptCharset = ""
http.UserAgent = ""
http.AcceptLanguage = ""
'  Suppress the Accept-Encoding header by disallowing
'  a gzip response:
http.AllowGzip = false

'  If a Cookie needs to be added, it may be added by calling
'  AddQuickHeader:
http.AddQuickHeader("Cookie","JSESSIONID=1234")

Dim jsonText As String
jsonText = "{""user"":""doctoravatar@penzance.com"",""forecast"":7,""t"":""vlIj"",""zip"":94089}"

'  To use SSL/TLS, simply use "https://" in the URL.

'  IMPORTANT: Make sure to change the URL, JSON text,
'  and other data items to your own values.  The URL used
'  in this example will not actually work.

Dim resp As Chilkat.HttpResponse
resp = http.PostJson("http://json.penzance.org/request",jsonText)
If (resp Is Nothing ) Then
    TextBox1.Text = TextBox1.Text & http.LastErrorText & vbCrLf
Else
    '  Display the JSON response.
    TextBox1.Text = TextBox1.Text & resp.BodyStr & vbCrLf
End If