Highlight Search Results

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Highlight Search Results

By Nick • December 4, 2007

Some search engines highlight the words that you searched for when they display their results. I have recently had a need to do this and rather than use someone elses code I thought I’d write my own.

It’s written in Visual Basic as a function but could quite easily be used in it’s own class for reuse through out your application.

You will also need to add some CSS to your stylesheet.

.highlight
{
background-color: Yellow;
font-weight: bold;
}



Public Function highlight(ByVal result As String, ByVal searchTerm As String) As String
        Dim currentPosition As Integer

        Dim indexPosition As Integer

        Dim startHighlight As String = "<span class=""highlight"">"

        Dim endHighlight As String = "</span>"
        If result.ToUpper.Contains(searchTerm.ToUpper) Then
            While currentPosition + searchTerm.Length < result.Length - 1
                If result.ToUpper.Substring(currentPosition, result.Length - currentPosition).Contains(searchTerm.ToUpper) Then
                    indexPosition = result.ToUpper.IndexOf(searchTerm.ToUpper, currentPosition)
                    result = result.Insert(indexPosition, startHighlight)

                    indexPosition = indexPosition + searchTerm.Length + startHighlight.Length
                    result = result.Insert(indexPosition, endHighlight)

                    currentPosition = indexPosition + searchTerm.Length + endHighlight.Length
                Else

                    currentPosition = result.Length

                End If
            End While
        End If
        Return result