複製與附加之比較

更新： November 2007

將 XNode (包括 XElement) 或 XAttribute 物件加入到新的樹狀結構時，如果新內容沒有父代，這些物件只會附加到 XML 樹狀結構。如果新內容已經成為父代，而且屬於其他 XML 樹狀結構的一部分，則會複製新內容。然後，新複製的內容會附加到新的 XML 樹狀結構。

範例

下列程式碼示範將成為父代的項目加入到樹狀結構時，以及將沒有父代的項目加入樹狀結構時的行為。

// Create a tree with a child element.
XElement xmlTree1 = new XElement("Root",
    new XElement("Child1", 1)
);

// Create an element that is not parented.
XElement child2 = new XElement("Child2", 2);

// Create a tree and add Child1 and Child2 to it.
XElement xmlTree2 = new XElement("Root",
    xmlTree1.Element("Child1"),
    child2
);

// Compare Child1 identity.
Console.WriteLine("Child1 was {0}",
    xmlTree1.Element("Child1") == xmlTree2.Element("Child1") ?
    "attached" : "cloned");

// Compare Child2 identity.
Console.WriteLine("Child2 was {0}",
    child2 == xmlTree2.Element("Child2") ?
    "attached" : "cloned");

' Create a tree with a child element.
Dim xmlTree1 As XElement = _
    <Root>
        <Child1>1</Child1>
    </Root>

' Create an element that is not parented.
Dim child2 As XElement = <Child2>2</Child2>

' Create a tree and add Child1 and Child2 to it.
Dim xmlTree2 As XElement = _
    <Root>
        <%= xmlTree1.<Child1>(0) %>
        <%= child2 %>
    </Root>

' Compare Child1 identity.
Console.WriteLine("Child1 was {0}", _
    IIf(xmlTree1.Element("Child1") Is xmlTree2.Element("Child1"), _
    "attached", "cloned"))

' Compare Child2 identity.
Console.WriteLine("Child2 was {0}", _
    IIf(child2 Is xmlTree2.Element("Child2"), _
    "attached", "cloned"))

這個範例會產生下列輸出：

Child1 was cloned
Child2 was attached

請參閱

概念

建立 XML 樹狀結構