HOW TO：尋找子項目 (XPath-LINQ to XML)

這個主題會比較 XPath 子項目座標軸與 LINQ to XML Element 方法。

XPath 運算式為 DeliveryNotes。

範例

這個範例會尋找子項目 DeliveryNotes。

此範例使用下列 XML 文件：XML 範例檔：多個採購訂單 (LINQ to XML)。

XDocument cpo = XDocument.Load("PurchaseOrders.xml");
XElement po = cpo.Root.Element("PurchaseOrder");

// LINQ to XML query
XElement el1 = po.Element("DeliveryNotes");

// XPath expression
XElement el2 = po.XPathSelectElement("DeliveryNotes");
// same as "child::DeliveryNotes"
// same as "./DeliveryNotes"

if (el1 == el2)
    Console.WriteLine("Results are identical");
else
    Console.WriteLine("Results differ");
Console.WriteLine(el1);

Dim cpo As XDocument = XDocument.Load("PurchaseOrders.xml")
Dim po As XElement = cpo.Root.<PurchaseOrder>.FirstOrDefault

'LINQ to XML query
Dim el1 As XElement = po.<DeliveryNotes>.FirstOrDefault

' XPath expression
Dim el2 As XElement = po.XPathSelectElement("DeliveryNotes")
' same as "child::DeliveryNotes"
' same as "./DeliveryNotes"

If el1 Is el2 Then
    Console.WriteLine("Results are identical")
Else
    Console.WriteLine("Results differ")
End If
Console.WriteLine(el1)

這個範例產生下列輸出：

Results are identical
<DeliveryNotes>Please leave packages in shed by driveway.</DeliveryNotes>

請參閱

概念

適用於 XPath 使用者的 LINQ to XML