2015-10-20 78 views
0

我想修改一个使用dotNetRDF的Rdf节点,然后将它保存在一个新文件中,但我得到的是同一个文件!替换节点DotnetRDF

我想将标识/ 12更改为标识/ 18。

模板文件:

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>. 
@prefix owl: <http://www.w3.org/2002/07/owl#>. 
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>. 
@prefix qudt: <http://qudt.org/schema/qudt#>. 
@prefix qudt-unit: <http://qudt.org/vocab/unit#>. 
@prefix knr: <http://kurl.org/NET/knr#>. 

@prefix keak: <http://kurl.org/NET/keak#>. 
@prefix keak-time: <http://kurl.org/NET/keak/time#>. 
@prefix keak-eval: <http://kurl.org/NET/keak/eval#>. 
@prefix keak-quantity: <http://kurl.org/NET/keak/quantity#>. 
@prefix keak-ev: <http://kurl.org/NET/keak/ev#>. 

@base <http://data.info/keak/knr/>. 

<Identification/12> a keak-ev:Identification. 

<Quantity/45> a qudt:Quantity ; 
    qudt:quantityType keak-quantity:ElectricConsumption . 

的VB.NET代码:

Dim gKnr As IGraph = New Graph() 
Dim ttlParser As TurtleParser = New TurtleParser() 

'Load the file template 
ttlParser.Load(gKnr, PATH_TEMPLATE) 
gKnr.BaseUri = New Uri(keak_BASE_URI_Knr) 

Dim oNode As INode = gKnr.CreateUriNode(New Uri("http://kurl.org/NET/keak/ev#Identification")) 

'retrieve the item 
Dim listRes As List(Of Triple) = gKnr.GetTriplesWithObject(oNode) 
'?s = http://data.info/keak/Knr/Identification/12 , 
'?p = http://www.w3.org/1999/02/22-rdf-syntax-ns#type , 
'?o = http://kurl.org/NET/keak/ev#Identification 

'modify the item 
Dim tIdentification As Triple 
If listRes.Count = 1 Then 
    tIdentification = listRes(0) 
    tIdentification.Subject.GraphUri = New Uri("http://data.info/kseak/knr/Identification/18") 

End If 

gKnr.Assert(tIdentification) 

' Serialisation and Save 
Dim ttlWriter As New CompressingTurtleWriter() 
ttlWriter.DefaultNamespaces = gKnr.NamespaceMap 
ttlWriter.Save(gKnr, PATH_NEW_FILE) 

回答

1

这是行不通的,GraphUriINode一个属性,指示其绘制一个节点来自并且与节点的实际URI无关

无论如何INode是不可变的,你不能像你试图做的那样改变节点的URI。

如果您希望更改RDF图中的URI,那么您需要使用该URI的所有三元组,并使用新的URI和Assert()创建新的三元组。

下面的例子可能是synactically不正确VB,但希望它会给你的总体思路:

Dim listRes As List(Of Triple) = gKnr.GetTriplesWithObject(oNode).ToList() 

For Each origTriple in listRes 
    gKnr.Retract(origTriple) 
    Dim newTriple as Triple 
    newTriple = new Triple(New Uri("http://data.info/kseak/knr/Identification/18"), origTriple.Predicate, origTriple.Object) 
    gKnr.Assert(newTriple) 
Next 

当然,如果你想改变的URI不仅仅是主体地位更加那么你就需要发生改变逻辑适当

0

谢谢robV,它帮了我很多,我得到了视觉异常,但我设法改正它,这是最终代码:

For Each origTriple In listRes 
     gKnr.Retract(origTriple) 
     Dim sNode As INode = gKnr.CreateUriNode(UriFactory.Create("http://data.info/keask/Knr/Identification/18")) 
     Dim newTriple As Triple 
     newTriple = New Triple(sNode, origTriple.Predicate, origTriple.Object) 
     gKnr.Assert(newTriple) 
    Next