如何从 XslTransform 迁移到 XslCompiledTransform

Question

我有以下代码需要从 VS 2003 (.Net 1.1) 迁移到 VS 2008 (.Net 2+) 但我收到编译错误 -

System.Xml.Xsl.XslTransform' 已过时：此类已被弃用。 我可能需要改用 System.Xml.Xsl.XslCompiledTransform 。 但我没有找到可以与原始代码的所有参数一起使用的匹配的 Load() 和 Transform() 重载版本。

在 MSDN [How to: Migrate Your XslTransform Code] 中我只发现了一些更简单的情况。 http://msdn.microsoft.com/en-us /library/aa983475%28VS.80%29.aspx 但在我的代码中我看到一些注释暗示添加的参数是用来避免异常的，所以我更喜欢使用这些参数。

有人可以帮忙迁移这段代码吗？

谢谢， Atara

' ----------------------------------------------------------------------   
' VS 2003 code:
' ----------------------------------------------------------------------

. . .

Dim myXslDoc As Xml.XmlDocument

' ----------------------------------------------------------------------   
  Public Sub mcSetParameters(ByVal srcFileName As String)
' ----------------------------------------------------------------------

 Me.myXslDoc = New Xml.XmlDocument 
 Me.myXslDoc.Load(srcFileName) 

End Sub


' ----------------------------------------------------------------------    
  Public Sub mcSetHtml()
' ----------------------------------------------------------------------

 Dim oXPathNav As System.Xml.XPath.XPathNavigator = xmlDoc.DocumentElement.CreateNavigator()

 Dim sbContent As New System.Text.StringBuilder
 Dim swContent As New System.IO.StringWriter(sbContent)        

 Dim args As New System.Xml.Xsl.XsltArgumentList
 args.AddParam("paramName1", "", paramVal1.ToString)
 args.AddParam("paramName2", "", paramVal2.ToString)

 Try
   ' Try to avoid "Invalid site" exception, by using XmlUrlResolver and Evidence.
   ' If the XSLT stylesheet . . . comes from a code base that you trust, Then use Me.GetType().Assembly.Evidence() 
   Dim resolver As System.Xml.XmlUrlResolver = New System.Xml.XmlUrlResolver
   resolver.Credentials = System.Net.CredentialCache.DefaultCredentials
   Dim xslt As System.Xml.Xsl.XslTransform = New System.Xml.Xsl.XslTransform 
   xslt.Load(Me.myXslDoc, resolver, Me.GetType().Assembly.Evidence())        
   xslt.Transform(oXPathNav, args, swContent, Nothing)                       
 Catch ex As Exception
   Debug.WriteLine("Exception: {0}", ex.ToString())
 End Try

 DoSomething(sbContent.ToString())

End Sub

' ----------------------------------------------------------------------

在我的旧代码中我有 xmlDoc 和 xslDoc，所以我现在的编译代码（尚未测试）是：

' ---------------------- -----------------------------------------------------------
' VS 2008 试用代码：

' ------------------------------------------------------ ----------------------------

  Dim sbContent As System.Text.StringBuilder = New System.Text.StringBuilder()
  Dim swContent As System.IO.StringWriter = New System.IO.StringWriter(sbContent)
  Dim contentWriter As System.Xml.XmlWriter = System.Xml.XmlWriter.Create(swContent)

  Dim args As New System.Xml.Xsl.XsltArgumentList()
  args.AddParam("paramName1", "", paramVal1.ToString)
  args.AddParam("paramName2", "", paramVal2.ToString)

  Try
    Dim resolver As New System.Xml.XmlUrlResolver
    resolver.Credentials = System.Net.CredentialCache.DefaultCredentials

    Dim evidence As System.Security.Policy.Evidence = Me.GetType().Assembly.Evidence
    Dim secureResolver As New System.Xml.XmlSecureResolver(resolver, evidence)
    Dim settings As New System.Xml.Xsl.XsltSettings(False, True)

    Dim xslt As New System.Xml.Xsl.XslCompiledTransform()  
    xslt.Load(Me.myXslDoc, settings, secureResolver)    
    xslt.Transform(xmlDoc, args, contentWriter)  
  Catch ex As Exception
    Debug.WriteLine("Exception: {0}", ex.ToString())
  End Try

  DoSomething(sbContent.ToString())

Answer 1

这些额外的参数不再由 XsltCompiledTransform 类直接公开。您现在可以使用您喜欢的任何 XmlReader 加载转换。

如果您需要额外的安全性，请创建一个使用 XmlSecureResolver 的 XmlReader：

Private MyXslDoc As String = "XslFilePath"
Public Sub LoadTransform(ByVal paramVal1 As Object, ByVal paramVal2 As Object)
    Dim args As New System.Xml.Xsl.XsltArgumentList
    args.AddParam("paramName1", "", paramVal1.ToString)
    args.AddParam("paramName2", "", paramVal2.ToString)

    Dim resolver As New System.Xml.XmlUrlResolver
    resolver.Credentials = System.Net.CredentialCache.DefaultCredentials
    Dim evidence As Evidence = Me.GetType().Assembly.Evidence
    Dim secureResolver As New XmlSecureResolver(resolver, evidence)
    Dim settings As New XmlReaderSettings
    settings.XmlResolver = secureResolver

    Dim xslt As New System.Xml.Xsl.XslCompiledTransform()
    Using transformReader As XmlReader = XmlReader.Create(Me.MyXslDoc, settings)
        xslt.Load(transformReader)
    End Using

    Using documentReader As XmlReader = XmlReader.Create(documentUri)
        Dim sbContent As New System.Text.StringBuilder
        Using swContent As New System.IO.StringWriter(sbContent)

            Using contentWriter As XmlWriter = XmlWriter.Create(swContent)
                xslt.Transform(documentReader, args, contentWriter, Nothing)
            End Using
        End Using
    End Using
End Sub