localize all href/src for a xml/html content string

gistfile1.vb

Public Shared Function LocalizeUrls(ByVal originalUrl As String, ByVal content As String) As String
	' make image src's and anchor href's absolute in the string _sourceHtml
	' get path for source
	Dim siteUri As New Uri(originalUrl)

	' modify img[@src] and a[@href]
	Dim sources As MatchCollection = Regex.Matches(content, "(src|href)=([""'])(?!\#|http)([^\2]+?)(\2)", RegexOptions.Compiled Or RegexOptions.CultureInvariant Or RegexOptions.IgnoreCase)
	For Each src As Match In sources
		Dim attribute As String = src.Groups(1).Value
		Dim quote As String = src.Groups(2).Value
		Dim url As String = src.Groups(3).Value
		' this will handle links like this: "../page", "/page", "page"
		Dim newUri As New Uri(siteUri, url)
		Dim originalSrc As String = src.Value
		Dim newSrc As String = attribute & "=" & quote & newUri.AbsoluteUri() & quote
		content = content.Replace(originalSrc, newSrc)
	Next
	Return content
End Function