Now it's time to see the full code (VB.NET). The C# equivalent can be done easily from this source.
The example included here uses a FileUpload web control and a simple button to convert the selected file and return it through a Literal control.
For the purpose of this article, I have kept all the code in one place, but you can also create a separate class if you need too. Because the source code is converted in HTML, it should not interfere with anything on the web page, but just in case I use a <pre> tag to clearly identify the result.
When you click the button a click event is raised, the language property is set up according to the file extension. Then the file is read and the render method is called up on the string.
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="CCodeToHTML._Default" %>
Imports System.IO
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Button1_Click(ByVal sender As Object,
ByVal e As System.EventArgs) Handles Button1.Click
If Not (FileUpload1.PostedFile Is Nothing) Then
Dim myFile As String = ""
Dim fileName As String = FileUpload1.PostedFile.FileName
SetLanguageFromFileName(fileName)
Dim srRead As StreamReader = File.OpenText(fileName)
FileResult.Text = Render(srRead)
End If
End Sub
Private _ShowFileName As Boolean = False
Private _FontSize As Integer = 3
Private _Language As String = ""
Private Const TAG_FNTRED As String = "<font color=""red"">"
Private Const TAG_FNTBLUE As String = "<font color=""blue"">"
Private Const TAG_FNTGRN As String = "<font color=""green"">"
Private Const TAG_FNTMRN As String = "<font color=""maroon"">"
Private Const TAG_EFONT As String = "</font>"
Public Property ShowFileName() As Boolean
Get
Return _ShowFileName
End Get
Set(ByVal Value As Boolean)
_ShowFileName = Value
End Set
End Property
Public Property FontSize() As Integer
Get
Return _FontSize
End Get
Set(ByVal Value As Integer)
_FontSize = Value
End Set
End Property
Public Property Language() As String
Get
Return _Language
End Get
Set(ByVal Value As String)
_Language = Value
End Set
End Property
Private Sub SetLanguageFromFileName(ByVal FilePath As String)
' Find the current language from the file extension
If FilePath.Split(Convert.ToChar(".")).Length > 0 Then
Dim sFileExtension As String = FilePath.Substring(FilePath.LastIndexOf(Convert.ToChar(".")) + 1)
Select Case sFileExtension.ToLower().Trim()
Case ProgrammingLanguage.VB
_Language = ProgrammingLanguage.VB
Case ProgrammingLanguage.CSharp
_Language = ProgrammingLanguage.CSharp
Case ProgrammingLanguage.JavaScript
_Language = ProgrammingLanguage.JavaScript
End Select
End If
End Sub
Public Overloads Function RenderFile(ByVal FilePath As String) As String
' errors?
SetLanguageFromFileName(FilePath)
Return Render(IO.File.OpenText(FilePath))
End Function
Public Overloads Sub RenderFile(ByVal FilePath As String,
ByVal OutputFilePath As String)
' Render and throw error
SetLanguageFromFileName(FilePath)
Dim MyStreamWriter As New IO.StreamWriter(OutputFilePath)
MyStreamWriter.Write(Render(IO.File.OpenText(FilePath)))
MyStreamWriter.Flush()
MyStreamWriter.Close()
End Sub
Public Overloads Function Render(ByVal InputTextReader As IO.StreamReader) As String
Return Render(InputTextReader.ReadToEnd())
End Function
Public Overloads Function Render(ByVal InputString As String) As String
Dim MyStringBuilder As New System.Text.StringBuilder()
Dim MyStringWriter As New System.IO.StringWriter(MyStringBuilder)
' Split into a string array for processing
Dim InputLines() As String = InputString.Split(vbCrLf)
Dim sInputLine As String
' Write out the font size
MyStringWriter.WriteLine("<font size=""" & _FontSize & """ \>")
' Process the language
Select Case _Language.Trim.ToLower()
Case ProgrammingLanguage.CSharp
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixCSLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case ProgrammingLanguage.JavaScript
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixJSLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case ProgrammingLanguage.VB
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixVBLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case Else
Dim bIsInScriptBlock As Boolean = False
Dim bIsInMultiLine As Boolean = False
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
' get the global language from a page directive
_Language = GetLanguageFromLine(sInputLine, _Language)
If IsScriptBlockTagStart(sInputLine) Then
MyStringWriter.Write(FixASPXLine(sInputLine))
bIsInScriptBlock = True
ElseIf IsScriptBlockTagEnd(sInputLine) Then
MyStringWriter.Write(FixASPXLine(sInputLine))
bIsInScriptBlock = False
ElseIf IsMultiLineTagStart(sInputLine) And bIsInMultiLine = False Then
MyStringWriter.Write("<font color=blue><b>" +
HttpUtility.HtmlEncode(sInputLine))
bIsInMultiLine = True
ElseIf IsMultiLineTagEnd(sInputLine) And bIsInMultiLine = True Then
MyStringWriter.Write(HttpUtility.HtmlEncode(sInputLine) +
"</b></font>")
bIsInMultiLine = False
ElseIf bIsInMultiLine Then
MyStringWriter.Write(HttpUtility.HtmlEncode(sInputLine))
Else
If bIsInScriptBlock Then
Select Case _Language.Trim.ToLower()
Case ProgrammingLanguage.CSharp
MyStringWriter.Write(FixCSLine(sInputLine))
Case ProgrammingLanguage.JavaScript
MyStringWriter.Write(FixJSLine(sInputLine))
Case ProgrammingLanguage.VB
MyStringWriter.Write(FixVBLine(sInputLine))
Case Else
MyStringWriter.Write(FixVBLine(sInputLine))
End Select
Else
MyStringWriter.Write(FixASPXLine(sInputLine))
End If
End If
Next
MyStringWriter.WriteLine("</pre>")
'aspx-page sorted out
End Select
MyStringWriter.WriteLine("</font>")
MyStringWriter.Flush()
Return MyStringBuilder.ToString()
End Function
Private Function GetLanguageFromLine(ByVal sInputLine As String,
ByVal DefaultLanguage As String) As String
' Returns name of the language
Dim sReturn As String = DefaultLanguage
If sInputLine.Length = 0 Then
Return sReturn
End If
Dim LanguageMatch As Match = RegularExpressions.Regex.Match(sInputLine,
"(?i)<%@\s*Page\s*.*Language\s*=\s*""(?<lang>[^""]+)""")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
LanguageMatch = RegularExpressions.Regex.Match(sInputLine,
"(?i)(?=.*runat\s*=\s*""?server""?)<script.*language\s*=\s*""(?<lang>[^""]+)"".*>")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
LanguageMatch = RegularExpressions.Regex.Match(sInputLine,
"(?i)<%@\s*WebService\s*.*Language\s*=\s*""?(?<lang>[^""]+)""?")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
' "CS" instead of "C#" ?
If sReturn = "CS" Then
sReturn = ProgrammingLanguage.CSharp
End If
Return sReturn
End Function
Private Function FixCSLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"private", "protected", "public", "namespace",
"class", "break", "for", "if", "else", "while", "switch", "case", "using", "return",
"null", "void", "int", "bool", "string", "float", "this", "new", "true", "false",
"const", "static", "base", "foreach", "in", "try", "catch", "get", "set", "char",
"default"}
Dim sCombinedKeywords As String = "(?<keyword>" &
String.Join("|", sKeywords) & ")"
sOutput = Regex.Replace(sOutput, "\b" & sCombinedKeywords & "\b(?<!//.*)",
TAG_FNTBLUE & "${keyword}" & TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>//.*$)", TAG_FNTGRN & "${comment}" & TAG_EFONT)
Return sOutput
End Function
Private Function FixJSLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"private", "protected", "public", "namespace",
"class", "var", "for", "if", "else", "while", "switch", "case", "using", "get",
"return", "null", "void", "int", "string", "float", "this", "set", "new", "true",
"false", "const", "static", "package", "function", "internal", "extends", "super",
"import", "default", "break", "try", "catch", "finally"}
Dim sCombinedKeywords As String = "(?<keyword>" &
String.Join("|", sKeywords) & ")"
sOutput = Regex.Replace(sOutput, "\b" + sCombinedKeywords + "\b(?<!//.*)",
TAG_FNTBLUE + "${keyword}" + TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>//.*$)", TAG_FNTGRN +
"${comment}" + TAG_EFONT)
Return sOutput
End Function
Private Function FixVBLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"AddressOf", "Delegate", "Optional", "ByVal",
"ByRef", "Decimal", "Boolean", "Option", "Compare", "Binary", "Text", "On", "Off",
"Explicit", "Strict", "Private", "Protected", "Public", "End Namespace", "Namespace",
"End Class", "Exit", "Class", "Goto", "Try", "Catch", "End Try", "For", "End If",
"If", "Else", "ElseIf", "Next", "While", "And", "Do", "Loop", "Dim", "As", "End
Select", "Select", "Case", "Or", "Imports", "Then", "Integer", "Long", "String",
"Overloads", "True", "Overrides", "End Property", "End Sub", "End Function", "Sub",
"Me", "Function", "End Get", "End Set", "Get", "Friend", "Inherits", "Implements",
"Return", "Not", "New", "Shared", "Nothing", "Finally", "False", "Me", "My", "MyBase",
"End Enum", "Enum"}
Dim CombinedKeywords As String = "(?<keyword>" + String.Join("|", sKeywords) + ")"
sOutput = Regex.Replace(sOutput, "(?i)\b" + CombinedKeywords + "\b(?<!'.*)",
TAG_FNTBLUE + "${keyword}" + TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>'(?![^']*").*$)",
TAG_FNTGRN + "${comment}" + TAG_EFONT)
Return sOutput
End Function
Private Function FixASPXLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
Dim sSearchExpression As String
Dim sReplaceExpression As String
If sInputLine.Length = 0 Then
Return sInputLine
End If
' Search for \t and replace it with 4 spaces
sOutput = Regex.Replace(sOutput, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
' Single line comment or #include references.
sSearchExpression = "(?i)(?<a>(^.*))(?<b>(<!--))(?<c>(.*))(?<d>(-->))(?<e>(.*))"
sReplaceExpression = "${a}" & TAG_FNTGRN & "${b}${c}${d}" & TAG_EFONT & "${e}"
If Regex.IsMatch(sOutput, sSearchExpression) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize <%@ <type>
sSearchExpression = "(?i)" + "(?<a>(<%@))" + "(?<b>(.*))" + "(?<c>(%>))"
sReplaceExpression = "<font color=blue><b>${a}${b}${c}</b></font>"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize <%# <type>
sSearchExpression = "(?i)" + "(?<a>(<%#))" + "(?<b>(.*))" + "(?<c>(%>))"
sReplaceExpression = "${a}" + "<font color=red><b>" + "${b}" + "</b></font>" + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize tag <type>
sSearchExpression = "(?i)" +
"(?<a>(<)(?!%)(?!/?asp:)(?!/?template)(?!/?property)(?!/?ibuyspy:)(/|!)?)" +
"(?<b>[^;\s&]+)" + "(?<c>(\s|>|\Z))"
sReplaceExpression = "${a}" + TAG_FNTMRN + "${b}" + TAG_EFONT + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize asp:|template for runat=server tags <type>
sSearchExpression =
"(?i)(?<a></?)(?<b>(asp:|template|property|IBuySpy:).*)(?<c>>)?"
sReplaceExpression = "${a}" + TAG_FNTBLUE + "<b>${b}</b>" + TAG_EFONT + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colourise begin of tag char(s) "<","</","<%"
sSearchExpression = "(?i)(?<a>(<)(/|!|%)?)"
sReplaceExpression = TAG_FNTBLUE + "${a}" + TAG_EFONT
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize end of tag char(s) ">","/>"
sSearchExpression = "(?i)(?<a>(/|%)?(>))"
sReplaceExpression = TAG_FNTBLUE + "${a}" + TAG_EFONT
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
Return sOutput
End Function
Private Function IsScriptBlockTagStart(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
If Regex.IsMatch(sInputLine, "<script.*runat=""?server""?.*>") Then
bReturn = True
ElseIf Regex.IsMatch(sInputLine, "(?i)<%@\s*WebService") Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsScriptBlockTagEnd(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
If (Regex.IsMatch(sInputLine, "</script.*>")) Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsMultiLineTagStart(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
Dim sOutput As String
Dim sSearchExpression As String =
"(?i)(?!.*>)(?<a></?)(?<b>(asp:|template|property|IBuySpy:).*)"
sOutput = HttpUtility.HtmlEncode(sInputLine)
If Regex.IsMatch(sOutput, sSearchExpression) Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsMultiLineTagEnd(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
Dim sOutput As String
Dim sSearchExpression As String = "(?i)>"
sOutput = HttpUtility.HtmlEncode(sInputLine)
If Regex.IsMatch(sOutput, sSearchExpression) Then
bReturn = True
End If
Return bReturn
End Function
Private Class ProgrammingLanguage
Public Const VB As String = "vb"
Public Const CSharp As String = "cs"
Public Const JavaScript As String = "js"
End Class
End Class
Imports System.IO
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Button1_Click(ByVal sender As Object,
ByVal e As System.EventArgs) Handles Button1.Click
If Not (FileUpload1.PostedFile Is Nothing) Then
Dim myFile As String = ""
Dim fileName As String = FileUpload1.PostedFile.FileName
SetLanguageFromFileName(fileName)
Dim srRead As StreamReader = File.OpenText(fileName)
FileResult.Text = Render(srRead)
End If
End Sub
Private _ShowFileName As Boolean = False
Private _FontSize As Integer = 3
Private _Language As String = ""
Private Const TAG_FNTRED As String = "<font color=""red"">"
Private Const TAG_FNTBLUE As String = "<font color=""blue"">"
Private Const TAG_FNTGRN As String = "<font color=""green"">"
Private Const TAG_FNTMRN As String = "<font color=""maroon"">"
Private Const TAG_EFONT As String = "</font>"
Public Property ShowFileName() As Boolean
Get
Return _ShowFileName
End Get
Set(ByVal Value As Boolean)
_ShowFileName = Value
End Set
End Property
Public Property FontSize() As Integer
Get
Return _FontSize
End Get
Set(ByVal Value As Integer)
_FontSize = Value
End Set
End Property
Public Property Language() As String
Get
Return _Language
End Get
Set(ByVal Value As String)
_Language = Value
End Set
End Property
Private Sub SetLanguageFromFileName(ByVal FilePath As String)
' Find the current language from the file extension
If FilePath.Split(Convert.ToChar(".")).Length > 0 Then
Dim sFileExtension As String = FilePath.Substring(FilePath.LastIndexOf(Convert.ToChar(".")) + 1)
Select Case sFileExtension.ToLower().Trim()
Case ProgrammingLanguage.VB
_Language = ProgrammingLanguage.VB
Case ProgrammingLanguage.CSharp
_Language = ProgrammingLanguage.CSharp
Case ProgrammingLanguage.JavaScript
_Language = ProgrammingLanguage.JavaScript
End Select
End If
End Sub
Public Overloads Function RenderFile(ByVal FilePath As String) As String
' errors?
SetLanguageFromFileName(FilePath)
Return Render(IO.File.OpenText(FilePath))
End Function
Public Overloads Sub RenderFile(ByVal FilePath As String,
ByVal OutputFilePath As String)
' Render and throw error
SetLanguageFromFileName(FilePath)
Dim MyStreamWriter As New IO.StreamWriter(OutputFilePath)
MyStreamWriter.Write(Render(IO.File.OpenText(FilePath)))
MyStreamWriter.Flush()
MyStreamWriter.Close()
End Sub
Public Overloads Function Render(ByVal InputTextReader As IO.StreamReader) As String
Return Render(InputTextReader.ReadToEnd())
End Function
Public Overloads Function Render(ByVal InputString As String) As String
Dim MyStringBuilder As New System.Text.StringBuilder()
Dim MyStringWriter As New System.IO.StringWriter(MyStringBuilder)
' Split into a string array for processing
Dim InputLines() As String = InputString.Split(vbCrLf)
Dim sInputLine As String
' Write out the font size
MyStringWriter.WriteLine("<font size=""" & _FontSize & """ \>")
' Process the language
Select Case _Language.Trim.ToLower()
Case ProgrammingLanguage.CSharp
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixCSLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case ProgrammingLanguage.JavaScript
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixJSLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case ProgrammingLanguage.VB
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
MyStringWriter.Write(FixVBLine(sInputLine))
Next
MyStringWriter.WriteLine("</pre>")
Case Else
Dim bIsInScriptBlock As Boolean = False
Dim bIsInMultiLine As Boolean = False
MyStringWriter.WriteLine("<pre>")
For Each sInputLine In InputLines
' get the global language from a page directive
_Language = GetLanguageFromLine(sInputLine, _Language)
If IsScriptBlockTagStart(sInputLine) Then
MyStringWriter.Write(FixASPXLine(sInputLine))
bIsInScriptBlock = True
ElseIf IsScriptBlockTagEnd(sInputLine) Then
MyStringWriter.Write(FixASPXLine(sInputLine))
bIsInScriptBlock = False
ElseIf IsMultiLineTagStart(sInputLine) And bIsInMultiLine = False Then
MyStringWriter.Write("<font color=blue><b>" +
HttpUtility.HtmlEncode(sInputLine))
bIsInMultiLine = True
ElseIf IsMultiLineTagEnd(sInputLine) And bIsInMultiLine = True Then
MyStringWriter.Write(HttpUtility.HtmlEncode(sInputLine) +
"</b></font>")
bIsInMultiLine = False
ElseIf bIsInMultiLine Then
MyStringWriter.Write(HttpUtility.HtmlEncode(sInputLine))
Else
If bIsInScriptBlock Then
Select Case _Language.Trim.ToLower()
Case ProgrammingLanguage.CSharp
MyStringWriter.Write(FixCSLine(sInputLine))
Case ProgrammingLanguage.JavaScript
MyStringWriter.Write(FixJSLine(sInputLine))
Case ProgrammingLanguage.VB
MyStringWriter.Write(FixVBLine(sInputLine))
Case Else
MyStringWriter.Write(FixVBLine(sInputLine))
End Select
Else
MyStringWriter.Write(FixASPXLine(sInputLine))
End If
End If
Next
MyStringWriter.WriteLine("</pre>")
'aspx-page sorted out
End Select
MyStringWriter.WriteLine("</font>")
MyStringWriter.Flush()
Return MyStringBuilder.ToString()
End Function
Private Function GetLanguageFromLine(ByVal sInputLine As String,
ByVal DefaultLanguage As String) As String
' Returns name of the language
Dim sReturn As String = DefaultLanguage
If sInputLine.Length = 0 Then
Return sReturn
End If
Dim LanguageMatch As Match = RegularExpressions.Regex.Match(sInputLine,
"(?i)<%@\s*Page\s*.*Language\s*=\s*""(?<lang>[^""]+)""")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
LanguageMatch = RegularExpressions.Regex.Match(sInputLine,
"(?i)(?=.*runat\s*=\s*""?server""?)<script.*language\s*=\s*""(?<lang>[^""]+)"".*>")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
LanguageMatch = RegularExpressions.Regex.Match(sInputLine,
"(?i)<%@\s*WebService\s*.*Language\s*=\s*""?(?<lang>[^""]+)""?")
If LanguageMatch.Success Then
sReturn = LanguageMatch.Groups("lang").ToString()
End If
' "CS" instead of "C#" ?
If sReturn = "CS" Then
sReturn = ProgrammingLanguage.CSharp
End If
Return sReturn
End Function
Private Function FixCSLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"private", "protected", "public", "namespace",
"class", "break", "for", "if", "else", "while", "switch", "case", "using", "return",
"null", "void", "int", "bool", "string", "float", "this", "new", "true", "false",
"const", "static", "base", "foreach", "in", "try", "catch", "get", "set", "char",
"default"}
Dim sCombinedKeywords As String = "(?<keyword>" &
String.Join("|", sKeywords) & ")"
sOutput = Regex.Replace(sOutput, "\b" & sCombinedKeywords & "\b(?<!//.*)",
TAG_FNTBLUE & "${keyword}" & TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>//.*$)", TAG_FNTGRN & "${comment}" & TAG_EFONT)
Return sOutput
End Function
Private Function FixJSLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"private", "protected", "public", "namespace",
"class", "var", "for", "if", "else", "while", "switch", "case", "using", "get",
"return", "null", "void", "int", "string", "float", "this", "set", "new", "true",
"false", "const", "static", "package", "function", "internal", "extends", "super",
"import", "default", "break", "try", "catch", "finally"}
Dim sCombinedKeywords As String = "(?<keyword>" &
String.Join("|", sKeywords) & ")"
sOutput = Regex.Replace(sOutput, "\b" + sCombinedKeywords + "\b(?<!//.*)",
TAG_FNTBLUE + "${keyword}" + TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>//.*$)", TAG_FNTGRN +
"${comment}" + TAG_EFONT)
Return sOutput
End Function
Private Function FixVBLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
If sInputLine.Length = 0 Then
Return sInputLine
End If
sOutput = Regex.Replace(sInputLine, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
Dim sKeywords() As String = {"AddressOf", "Delegate", "Optional", "ByVal",
"ByRef", "Decimal", "Boolean", "Option", "Compare", "Binary", "Text", "On", "Off",
"Explicit", "Strict", "Private", "Protected", "Public", "End Namespace", "Namespace",
"End Class", "Exit", "Class", "Goto", "Try", "Catch", "End Try", "For", "End If",
"If", "Else", "ElseIf", "Next", "While", "And", "Do", "Loop", "Dim", "As", "End
Select", "Select", "Case", "Or", "Imports", "Then", "Integer", "Long", "String",
"Overloads", "True", "Overrides", "End Property", "End Sub", "End Function", "Sub",
"Me", "Function", "End Get", "End Set", "Get", "Friend", "Inherits", "Implements",
"Return", "Not", "New", "Shared", "Nothing", "Finally", "False", "Me", "My", "MyBase",
"End Enum", "Enum"}
Dim CombinedKeywords As String = "(?<keyword>" + String.Join("|", sKeywords) + ")"
sOutput = Regex.Replace(sOutput, "(?i)\b" + CombinedKeywords + "\b(?<!'.*)",
TAG_FNTBLUE + "${keyword}" + TAG_EFONT)
sOutput = Regex.Replace(sOutput, "(?<comment>'(?![^']*").*$)",
TAG_FNTGRN + "${comment}" + TAG_EFONT)
Return sOutput
End Function
Private Function FixASPXLine(ByVal sInputLine As String) As String
Dim sOutput As String = sInputLine
Dim sSearchExpression As String
Dim sReplaceExpression As String
If sInputLine.Length = 0 Then
Return sInputLine
End If
' Search for \t and replace it with 4 spaces
sOutput = Regex.Replace(sOutput, "(?i)(\t)", " ")
sOutput = HttpUtility.HtmlEncode(sOutput)
' Single line comment or #include references.
sSearchExpression = "(?i)(?<a>(^.*))(?<b>(<!--))(?<c>(.*))(?<d>(-->))(?<e>(.*))"
sReplaceExpression = "${a}" & TAG_FNTGRN & "${b}${c}${d}" & TAG_EFONT & "${e}"
If Regex.IsMatch(sOutput, sSearchExpression) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize <%@ <type>
sSearchExpression = "(?i)" + "(?<a>(<%@))" + "(?<b>(.*))" + "(?<c>(%>))"
sReplaceExpression = "<font color=blue><b>${a}${b}${c}</b></font>"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize <%# <type>
sSearchExpression = "(?i)" + "(?<a>(<%#))" + "(?<b>(.*))" + "(?<c>(%>))"
sReplaceExpression = "${a}" + "<font color=red><b>" + "${b}" + "</b></font>" + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize tag <type>
sSearchExpression = "(?i)" +
"(?<a>(<)(?!%)(?!/?asp:)(?!/?template)(?!/?property)(?!/?ibuyspy:)(/|!)?)" +
"(?<b>[^;\s&]+)" + "(?<c>(\s|>|\Z))"
sReplaceExpression = "${a}" + TAG_FNTMRN + "${b}" + TAG_EFONT + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize asp:|template for runat=server tags <type>
sSearchExpression =
"(?i)(?<a></?)(?<b>(asp:|template|property|IBuySpy:).*)(?<c>>)?"
sReplaceExpression = "${a}" + TAG_FNTBLUE + "<b>${b}</b>" + TAG_EFONT + "${c}"
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colourise begin of tag char(s) "<","</","<%"
sSearchExpression = "(?i)(?<a>(<)(/|!|%)?)"
sReplaceExpression = TAG_FNTBLUE + "${a}" + TAG_EFONT
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
' Colorize end of tag char(s) ">","/>"
sSearchExpression = "(?i)(?<a>(/|%)?(>))"
sReplaceExpression = TAG_FNTBLUE + "${a}" + TAG_EFONT
If (Regex.IsMatch(sOutput, sSearchExpression)) Then
sOutput = Regex.Replace(sOutput, sSearchExpression, sReplaceExpression)
End If
Return sOutput
End Function
Private Function IsScriptBlockTagStart(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
If Regex.IsMatch(sInputLine, "<script.*runat=""?server""?.*>") Then
bReturn = True
ElseIf Regex.IsMatch(sInputLine, "(?i)<%@\s*WebService") Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsScriptBlockTagEnd(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
If (Regex.IsMatch(sInputLine, "</script.*>")) Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsMultiLineTagStart(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
Dim sOutput As String
Dim sSearchExpression As String =
"(?i)(?!.*>)(?<a></?)(?<b>(asp:|template|property|IBuySpy:).*)"
sOutput = HttpUtility.HtmlEncode(sInputLine)
If Regex.IsMatch(sOutput, sSearchExpression) Then
bReturn = True
End If
Return bReturn
End Function
Private Function IsMultiLineTagEnd(ByVal sInputLine As String) As Boolean
Dim bReturn As Boolean = False
Dim sOutput As String
Dim sSearchExpression As String = "(?i)>"
sOutput = HttpUtility.HtmlEncode(sInputLine)
If Regex.IsMatch(sOutput, sSearchExpression) Then
bReturn = True
End If
Return bReturn
End Function
Private Class ProgrammingLanguage
Public Const VB As String = "vb"
Public Const CSharp As String = "cs"
Public Const JavaScript As String = "js"
End Class
End Class
You've now learned how to convert and colorize a code source to HTML. Following the guidelines in this article, you might also look at extending the languages list or why not add more new keywords for C# 3.0 and above. I would be interested to know about any developments you can add from this example.
Printing with a browser: contrary to most browsers, java is known to have a very bad and buggy printing support
