XML模式驗證 - 行號始終返回0

Question

我正在使用以下代碼驗證Schema和XML文件。

Public Sub LoadXml(xmlFilePath As String, xsdFilePath As String) 
    Dim doc As New XmlDocument() 
    doc.Load(xmlFilePath) 
    doc.Schemas.Add(Nothing, xsdFilePath) 
    Dim errorBuilder As New XmlValidationErrorBuilder() 
    doc.Validate(New ValidationEventHandler(AddressOf errorBuilder.ValidationEventHandler)) 
    Dim errorsText As List(Of String) = errorBuilder.GetErrors() 
End Sub 
End Class 

Public Class XmlValidationErrorBuilder 
Private _errors As New List(Of ValidationEventArgs)() 

Public Sub ValidationEventHandler(ByVal sender As Object, ByVal args As ValidationEventArgs) 
    If args.Severity = XmlSeverityType.Error Then 
     _errors.Add(args) 
    End If 
End Sub 

Public Function GetErrors() As List(Of String) 
    If _errors.Count <> 0 Then 
     Dim ErrorList As New List(Of String) 

     For i As Integer = 0 To _errors.Count - 1 
      Dim Message As String = _errors(i).Message 
      Dim LineNumber As String = _errors(i).Exception.LineNumber 
      Dim LinePosition As String = _errors(i).Exception.LinePosition 
      Dim combineString = Message & "|" & LineNumber & "|" & LinePosition 
      ErrorList.Add(combineString) 
     Next 
     Return ErrorList 
    Else 
     Return Nothing 
    End If 
End Function 

任何驗證錯誤都存儲在List（ValidationEventArgs）中，稍後由GetErrors函數處理。我的問題是，Exception.LineNumber和Exception.LinePosition總是返回0.我怎樣才能得到錯誤的行號和行位置？

Answer 1

LineNumber和LinePosition僅在最初加載XmlDocument時可用。如果您事後致電Validate，他們將不會被填充。原因是在加載文檔後，它已被轉換爲不再維護來自源流的定位信息的對象圖;原始的「文本」版本已被丟棄。

做驗證，同時加載你需要做的是這樣的：

Private Shared Function GetSchemaErrors(fileName As String) As List(Of XmlSchemaException) 
    Dim errors As New List(Of XmlSchemaException)() 

    Dim settings As New XmlReaderSettings() 
    settings.Schemas = New XmlSchemaSet() 
    settings.Schemas.Add(Nothing, "Path to .xsd file") 
    settings.ValidationType = ValidationType.Schema 
    AddHandler settings.ValidationEventHandler, 
     Sub(sender, args) errors.Add(args.Exception) 

    Dim reader As XmlReader = XmlReader.Create(fileName, settings) 
    Dim doc = New XmlDocument 
    doc.Load(reader) 

    Return errors 
End Function