download/upload to websites using WebClient

[Phill64]

Ok, a few people have asked about sending data to a website like a browser (simulating the <form> in html pages)

here's an example form on a website

<form method="post" action="http://themis.**********.com/cgi-bin/search.cgi">
  	<select name="D1" size="1">
		<option value="subject">Article Content</option>
		<option value="name">Author name</option>
		<option value="eseek">Web Search</option>
	</select>&nbsp; 	<input type="text" name="term" size="12">
                   <input name="search" type="image" src="images/go.gif" alt="Search Now!" align="middle" border="0">
</form>

so the fields you need to send are "D1", "term" and probably not needed for this site but for HTML standards sake also "search" (the button pressed)

NOTE: when value is set in the <option> tag within <select> tag this is what you send.

we send a fieldname/value object where we set these fields, the response will be in byte form, we need to convert it to ASCII to read it

        Dim wc As New Net.WebClient 'the webclient
        Dim bt() As Byte 'the returned bytes
        Dim html As String 'the returned HTML text

        'setup fields to be sent
        Dim fields As New Specialized.NameValueCollection
        fields.Add("D1", "subject") 'search option
        fields.Add("term", "test") 'search box
        fields.Add("search", "") 'button pressed

        bt = wc.UploadValues("http://themis.**********.com/cgi-bin/search.cgi", fields) 'send fields and retrieve response
        html = System.Text.Encoding.ASCII.GetString(bt) 'convert to text

        MsgBox(html)

this example sends the search "test" to the webpage and returns the results in HTML