Karl Moore's book, The Ultimate VB .NET and ASP.NET Code Book, has a
function that does just this.
You can download the supporting source here -
http://apress.com/book/sourceDownload.html?bID=178&sID=1128 and the
project is in a folder named Ch2 - RTF to HTML once you unzip it all.
Here's the function in question....
Public Function ConvertToHTML(ByVal Box As RichTextBox) As String
' Takes a RichTextBox control and returns a
' simple HTML-formatted version of its contents
Dim strHTML As String
Dim strColour As String
Dim blnBold As Boolean
Dim blnItalic As Boolean
Dim strFont As String
Dim shtSize As Short
Dim lngOriginalStart As Long
Dim lngOriginalLength As Long
Dim intCount As Integer
' If nothing in the box, exit
If Box.Text.Length = 0 Then Exit Function
' Store original selections, then select first character
lngOriginalStart = 0
lngOriginalLength = Box.TextLength
Box.Select(0, 1)
' Add HTML header
strHTML = "<html>"
' Setup initial parameters
strColour = Box.SelectionColor.ToKnownColor.ToString
blnBold = Box.SelectionFont.Bold
blnItalic = Box.SelectionFont.Italic
strFont = Box.SelectionFont.FontFamily.Name
shtSize = Box.SelectionFont.Size
' Include first 'style' parameters in the HTML
strHTML += "<span style=""font-family: " & strFont & _
"; font-size: " & shtSize & "pt; color: " & strColour & """>"
' Include bold tag, if required
If blnBold = True Then
strHTML += "<b>"
End If
' Include italic tag, if required
If blnItalic = True Then
strHTML += "<i>"
End If
' Finally, add our first character
strHTML += Box.Text.Substring(0, 1)
' Loop around all remaining characters
For intCount = 2 To Box.Text.Length
' Select current character
Box.Select(intCount - 1, 1)
' If this is a line break, add HTML tag
If Box.Text.Substring(intCount - 1, 1) = Convert.ToChar(10)
Then
strHTML += "<br>"
End If
' Check/implement any changes in style
If Box.SelectionColor.ToKnownColor.ToString <> strColour _
Or Box.SelectionFont.FontFamily.Name <> strFont Or _
Box.SelectionFont.Size <> shtSize Then
strHTML += "</span><span style=""font-family: " _
& Box.SelectionFont.FontFamily.Name & _
"; font-size: " & Box.SelectionFont.Size & _
"pt; color: " & _
Box.SelectionColor.ToKnownColor.ToString & """>"
End If
' Check for bold changes
If Box.SelectionFont.Bold <> blnBold Then
If Box.SelectionFont.Bold = False Then
strHTML += "</b>"
Else
strHTML += "<b>"
End If
End If
' Check for italic changes
If Box.SelectionFont.Italic <> blnItalic Then
If Box.SelectionFont.Italic = False Then
strHTML += "</i>"
Else
strHTML += "<i>"
End If
End If
' Add the actual character
strHTML += Mid(Box.Text, intCount, 1)
' Update variables with current style
strColour = Box.SelectionColor.ToKnownColor.ToString
blnBold = Box.SelectionFont.Bold
blnItalic = Box.SelectionFont.Italic
strFont = Box.SelectionFont.FontFamily.Name
shtSize = Box.SelectionFont.Size
Next
' Close off any open bold/italic tags
If blnBold = True Then strHTML += "</b>"
If blnItalic = True Then strHTML += "</i>"
' Terminate outstanding HTML tags
strHTML += "</span></html>"
' Restore original RichTextBox selection
Box.Select(lngOriginalStart, lngOriginalLength)
' Return HTML
Return strHTML
End Function
