Windows Form Richtextbox. How to find bold, underline, and other text formatting in 'rtf' and insert other tags for 3rd party vendor

Question

Thanks for reading.

I am storing RTF text in a database column that can contain bold, italics, underline, and other text formatting from a Windows form Richtextbox. We need to export the text to a 3rd party vendor that has a different defined set of tags that tells the vendor how to format the text. Unfortunately, the 3rd party vendor cannot read RTF format nor can they read HTML, XML, etc.

We need to export the 'plain' text in the richtextbox but find where the user added bold, italic, underline, and other formatting to the text and replace with the 3rd party vendor tags.

For example... I need to parse through something like the rtf below...

{\\rtf1\\ansi\\ansicpg1252\\deff0\\deflang1033{\\fonttbl{\\f0\\fnil\\fcharset0 Verdana;}} \\viewkind4\\uc1\\pard\\f0\\fs18 This is \\b bold\\par \\par \\b0 This is\\b \\b0\\i italics\\par \\par \\i0 This is \\ul underline\\ulnone\\par }

and create something like this:

"this is [B]bold[B]

this is [I]italics[I]

this is [U]underline[U]"

Does anyone know how this could be accomplished?

Greatly appreciate any help.

Answer 1

Thanks for all of your comments. Although not very efficient nor elegant this is getting what I need. Thank you all again.

 Public Shared Function ParseRTF(ByRef rtf As RichTextBox) As String
        Dim returnText As String = ""
        Dim isBold As Boolean = False
        Dim isUnderline As Boolean = False
        Dim isItalics As Boolean = False
        Dim isBullets As Boolean = False

        Dim isBoldBegin As Boolean = False
        Dim isUnderlineBegin As Boolean = False
        Dim isItalicsBegin As Boolean = False
        Dim isBulletsBegin As Boolean = False

        Dim isBoldEnd As Boolean = False
        Dim isUnderlineEnd As Boolean = False
        Dim isItalicsEnd As Boolean = False
        Dim isBulletsEnd As Boolean = False

        Dim tags As String = String.Empty

        Dim bold As String = "<B>"
        Dim underline As String = "<U>"
        Dim italics As String = "<I>"
        Dim bullet As String = "<T2><BULLET>"
        Dim newLine As String = "<NL>"
        Dim lastChar As String = String.Empty

        rtf.SelectionStart = 0
        rtf.SelectionLength = 0

        Try

            For x As Integer = 0 To rtf.TextLength - 1
                rtf.SelectionStart = x
                rtf.SelectionLength = 1
                tags = String.Empty
                isBoldBegin = False
                isBoldEnd = False
                isUnderlineBegin = False
                isUnderlineEnd = False
                isItalicsBegin = False
                isItalicsEnd = False

                'Test if text has formatting
                If rtf.SelectionFont.Bold Then
                    If Not isBold Then
                        isBoldBegin = True
                        isBold = True
                        isBoldEnd = False
                    End If
                Else
                    If isBold Then
                        isBoldBegin = False
                        isBold = False
                        isBoldEnd = True
                    End If
                End If

                If rtf.SelectionFont.Italic Then
                    If Not isItalics Then
                        isItalicsBegin = True
                        isItalics = True
                        isItalicsEnd = False
                    End If
                Else
                    If isItalics Then
                        isItalicsBegin = False
                        isItalics = False
                        isItalicsEnd = True
                    End If
                End If

                If rtf.SelectionFont.Underline Then
                    If Not isUnderline Then
                        isUnderlineBegin = True
                        isUnderline = True
                        isUnderlineEnd = False
                    End If
                Else
                    If isUnderline Then
                        isUnderlineBegin = False
                        isUnderline = False
                        isUnderlineEnd = True
                    End If
                End If
                'END Test if text has formatting


                ' Do reverse order if for any "END" tags
                If isUnderlineEnd Then
                    tags += underline
                End If

                If isItalicsEnd Then
                    tags += italics
                End If

                If isBoldEnd Then
                    tags += bold
                End If

                'Work with beginning tags
                If isBoldBegin Then
                    tags += bold
                End If

                If isItalicsBegin Then
                    tags += italics
                End If

                If isUnderlineBegin Then
                    tags += underline
                End If

                If x = rtf.TextLength - 1 Then
                    If isUnderline Then
                        lastChar += underline
                    End If
                    If isItalics Then
                        lastChar += italics
                    End If
                    If isBold Then
                        lastChar += bold
                    End If
                End If

                If rtf.SelectedText.Contains(vbLf) Then
                    If Not String.IsNullOrWhiteSpace(tags) Then
                        If isBoldBegin Or isUnderlineBegin Or isItalicsBegin Then
                            returnText += newLine & tags
                        End If

                        If isBoldEnd Or isUnderlineEnd Or isItalicsEnd Then
                            returnText += tags & newLine
                        End If
                    Else
                        returnText += newLine
                    End If
                Else
                    returnText += tags & rtf.SelectedText
                End If

                If Not String.IsNullOrWhiteSpace(lastChar) Then
                    returnText += lastChar
                End If
            Next

            Return returnText


        Catch ex As Exception
            Throw New CvrException(ex, ErrorCodes.UNKNOWN_ERROR)
        Finally
        End Try
    End Function