xml - 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。但是我没有找到可以与原始代码的所有参数一起使用的匹配 Load() 和 Transform() 重载版本。

在 MSDN [How to: Migrate Your XslTransform Code] 中我只找到了一些更简单的案例。 http://msdn.microsoft.com/en-us/library/aa983475%28VS.80%29.aspx但是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，阿塔拉

' ----------------------------------------------------------------------   
' 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，我同时拥有 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

XsltCompiledTransform 类不再直接公开这些额外参数。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，则创建一个使用 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