XmlDocument遞歸節點處理示例

Question

這不是一個問題，而是一個可能對像我這樣想研究VB.NET XmlDocument節點層次結構如何工作的人有用的示例。

下面的子過程遞歸遍歷XML文檔樹顯示元素和屬性遇到...

Private Sub XmlDocumentWalker(XmlNode As XmlNode) 

    If TypeOf XmlNode Is XmlComment Then 

     MsgBox(XmlNode.Value, MsgBoxStyle.OkOnly, "XML Comment") 

     If XmlNode.HasChildNodes Then XmlDocumentWalker(XmlNode.FirstChild) 
     If Not IsNothing(XmlNode.NextSibling) Then XmlDocumentWalker(XmlNode.NextSibling) 

    ElseIf TypeOf XmlNode Is XmlElement Then 

     If XmlNode.HasChildNodes And (TypeOf XmlNode.FirstChild Is XmlText) Then 

      MsgBox(XmlNode.Name & "=""" & XmlNode.FirstChild.Value & """", MsgBoxStyle.OkOnly, "XML Element") 

     Else 

      MsgBox(XmlNode.Name, MsgBoxStyle.OkOnly, "XML Element") 

     End If 

     If DirectCast(XmlNode, XmlElement).HasAttributes Then 
      For Each XmlAttribute As XmlNode In DirectCast(XmlNode, XmlElement).Attributes 

       MsgBox(XmlAttribute.Name & "=""" & XmlAttribute.Value & """", MsgBoxStyle.OkOnly, "XML Attribute") 

      Next 
     End If 

     If XmlNode.HasChildNodes And Not (TypeOf XmlNode.FirstChild Is XmlText) Then XmlDocumentWalker(XmlNode.FirstChild) 
     If Not IsNothing(XmlNode.NextSibling) Then XmlDocumentWalker(XmlNode.NextSibling) 
    End If 
End Sub 

下面的代碼提供給真正說明加載XML文檔由XMLDocumentWalker子程序走：

Private XmlDocument As XmlDocument 

Private ValidationErrorCount As Integer 

Public Sub Load() 
    ValidationErrorCount = 0 

    Try 
     Dim XmlReader As XmlReader 
     Dim XmlReaderSettings As New XmlReaderSettings() 
     Dim ValidationEventHandler As New ValidationEventHandler(AddressOf XMLValidationErrorMessage) 

     XmlReaderSettings.ValidationType = ValidationType.DTD 
     XmlReaderSettings.DtdProcessing = DtdProcessing.Parse 

     AddHandler XmlReaderSettings.ValidationEventHandler, ValidationEventHandler 

     XmlReader = XmlReader.Create(FileName, XmlReaderSettings) 

     XmlDocument = New XmlDocument() 

     XmlDocument.Load(XmlReader) 

     If 0 = ValidationErrorCount Then 
      XmlDocumentWalker(XmlDocument) 
     End If 

    Catch Exception As Exception 
     XmlDocument = Nothing 
     MsgBox(Exception.Message, MsgBoxStyle.Information + MsgBoxStyle.OkOnly, "Configuration file load error") 
    End Try 
End Sub 

Private Sub XMLValidationErrorMessage(ByVal sender As Object, ByVal args As ValidationEventArgs) 
    If 0 = ValidationErrorCount Then 
     MsgBox(ConfigurationResource, MsgBoxStyle.Information + MsgBoxStyle.OkOnly, "Configuration file invalid") 
    End If 

    MsgBox(args.Message, MsgBoxStyle.Information + MsgBoxStyle.OkOnly, "XML format error") 

    ValidationErrorCount += 1 
End Sub 

Answer 1

因爲這真的不是問題 - 我將它標記爲已回答。