VB.NET en boucle par XML pour stocker dans singleton

Question

Je suis un problème avec une boucle à travers un fichier XML et stocker la valeur dans un singleton

Mon XML ressemble à ceci

<values> 
    <value></value> 
    <value>$1</value>   
    <value>$5,000</value>  
    <value>$10,000</value>  
    <value>$15,000</value>  
    <value>$25,000</value>  
    <value>$50,000</value>  
    <value>$75,000</value>  
    <value>$100,000</value>  
    <value>$250,000</value>  
    <value>$500,000</value>  
    <value>$750,000</value>  
    <value>$1,000,000</value> 
    <value>$1,250,000</value> 
    <value>$1,500,000</value> 
    <value>$1,750,000</value> 
    <value>$2,000,000</value> 
    <value>$2,500,000</value> 
    <value>$3,000,000</value> 
    <value>$4,000,000</value> 
    <value>$5,000,000</value> 
    <value>$7,500,000</value> 
    <value>$10,000,000</value> 
    <value>$15,000,000</value> 
    <value>$25,000,000</value> 
    <value>$50,000,000</value> 
    <value>$100,000,000</value> 
    <value>$100,000,000+</value> 
</values> 

et ma fonction ressemble à ceci

Public Class LoadValues 
    Private Shared SearchValuesInstance As List(Of SearchValues) = Nothing 

    Public Shared ReadOnly Property LoadSearchValues As List(Of SearchValues) 
     Get 
      Dim sv As New List(Of SearchValues) 

      If SearchValuesInstance Is Nothing Then 
       Dim objDoc As XmlDocument = New XmlDataDocument 
       Dim objRdr As XmlTextReader = New XmlTextReader(HttpContext.Current.Server.MapPath("~/App_Data/Search-Values.xml")) 
       objRdr.Read() 
       objDoc.Load(objRdr) 

       Dim root As XmlElement = objDoc.DocumentElement 
       Dim itemNodes As XmlNodeList = root.SelectNodes("/values") 

       For Each n As XmlNode In itemNodes 
        sv.Add(New SearchValues(n("@value").InnerText, n("@value").InnerText)) 
       Next 
       SearchValuesInstance = sv 

      Else : sv = SearchValuesInstance 
      End If 

      Return sv 
     End Get 
    End Property 

End Class 

mon problème est que je reçois un object not set to an instance of an object sur la ligne sv.Add(New SearchValues(n("@value").InnerText, n("@value").InnerText)).

Answer 1

Ok, j'ai l'impression d'avoir trouvé ma réponse. Espérons que cela aidera la prochaine personne avec le même problème.

Public Class LoadValues 
    Private Shared SearchValuesInstance As List(Of SearchValues) = Nothing 

    Public Shared ReadOnly Property LoadSearchValues As List(Of SearchValues) 
     Get 
      Dim sv As New List(Of SearchValues) 

      If SearchValuesInstance Is Nothing Then 

       Dim objDoc As XmlDocument = New XmlDataDocument 
       objDoc.Load(HttpContext.Current.Server.MapPath("~/App_Data/Search-Values.xml")) 

       Dim root As XmlNode = objDoc.DocumentElement 
       Dim nodelist As XmlNodeList = root.SelectNodes("/values/value") 

       Dim value As Double 

       For Each n As XmlNode In nodelist 
        value = If(BizHelper.ConvertToDouble(n.InnerText) Is Nothing, 0, BizHelper.ConvertToDouble(n.InnerText)) 
        sv.Add(New SearchValues(n.InnerText, value)) 
       Next 

       SearchValuesInstance = sv 

      Else : sv = SearchValuesInstance 
      End If 

      Return sv 
     End Get 
    End Property 

    Public Shared Sub DisposeSearchValues() 
     SearchValuesInstance = Nothing 
    End Sub 

End Class