Here’s a snippet to get the selected text from the WebBrowser control. Your project will need a reference to the Microsoft HTML Object Library (mshtml).
Dim doc As mshtml.IHTMLDocument2 = WebBrowser1.Document.DomDocument
Dim currentSelection As mshtml.IHTMLSelectionObject = doc.selection
If currentSelection IsNot Nothing Then
Dim range As mshtml.IHTMLTxtRange = currentSelection.createRange
If range IsNot Nothing Then
MessageBox.Show(range.text)
End If
End If