Gath Adams

Adding your own ‘Tweet This’ buttons so your visitors can post to twitter (complete with URL shortening using Bit.ly) is really easy.

Just add a page ‘twitter.aspx’ to your site and remove all the HTML from the page.

Add this code:

Imports System.Net

Partial Public Class Twitter

    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If Request.QueryString("url") <> "" And Request.QueryString("com") <> "" Then

            TweetThis(Request.QueryString("url"), Request.QueryString("com"))

        End If

    End Sub

    Private Sub TweetThis(ByVal sIWTFURL As String, ByVal sComment As String)

        Dim sShortURL As String

        Dim sFullTweet As String

        sShortURL = ShortenURL(sIWTFURL)

        sFullTweet = sComment & " - " & sShortURL

        SentToTwitter(sFullTweet)

    End Sub

    Private Function ShortenURL(ByVal sURL As String) As String

        Dim sJSON As String

        Dim oWebClient As New WebClient

        Dim sBitlyURL As String

        Dim sShortURL As String

        sBitlyURL = "http://api.bit.ly/shorten?version=2.0.1&longUrl=" & Server.UrlEncode(sURL) & "&login=bitlyapidemo&apiKey=R_0da49e0a9118ff35f52f629d2d71bf07"

        sJSON = oWebClient.DownloadString(sBitlyURL)

        sJSON = Mid$(sJSON, InStr(sJSON, Chr(34) & "shortUrl" & Chr(34)) + 9)

        Do While sJSON.ToLower.StartsWith("http://") = False

            sJSON = Mid$(sJSON, 2)

        Loop

        sShortURL = sJSON.Split(Chr(34))(0)

        ShortenURL = sShortURL

    End Function

    Private Sub SentToTwitter(ByVal sComments As String)

        Dim sURL As String

        sURL = "http://twitter.com/home/?status=" & HttpUtility.UrlEncode(sComments)

        Response.Redirect(sURL, False)

    End Sub

End Class

Note: I am using the default Bit.ly login in the example, you should sign up for your own bit.ly account so you can track usage of your links.

Now you just need to add some javascript to your html pages:

<a href="#" onClick='javascript:PostToTwitter()'>Tweet This</a>

<script>
function PostToTwitter()
{
var sTweet = 'This is the default text that will appear in the tweet';
var ShareURL = window.location.href;

window.open('http://yoursite.com/twitter.aspx?url='+encodeURIComponent(ShareURL)+'&com='+encodeURIComponent(sTweet));
return false;
}
</script>