XNode.IsBefore(XNode) 方法

定義

根據文件順序,判斷目前的節點是否出現在指定的節點之前。Determines if the current node appears before a specified node in terms of document order.

public:
 bool IsBefore(System::Xml::Linq::XNode ^ node);
public bool IsBefore (System.Xml.Linq.XNode node);
member this.IsBefore : System.Xml.Linq.XNode -> bool
Public Function IsBefore (node As XNode) As Boolean

參數

node
XNode

要針對文件順序比較的 XNodeThe XNode to compare for document order.

傳回

如果這個節點出現在指定的節點之前則為 true,否則為 falsetrue if this node appears before the specified node; otherwise false.

範例

下列範例會使用這個方法。The following example uses this method.

XElement xmlTree = new XElement("Root",  
    new XText("Text content."),  
    new XElement("Child1", "child1 content"),  
    new XElement("Child2", "child2 content"),  
    new XElement("Child3", "child3 content"),  
    new XText("More text content."),  
    new XElement("Child4", "child4 content"),  
    new XElement("Child5", "child5 content")  
);  
XElement child3 = xmlTree.Element("Child3");  
XElement child5 = xmlTree.Element("Child5");  
if (child5.IsBefore(child3))  
    Console.WriteLine("Child5 is before Child3");  
else  
    Console.WriteLine("Child5 is not before Child3");  
Dim xmlTree As XElement = _   
        <Root>Text content.  
            <Child1>child1 content</Child1>  
            <Child2>child2 content</Child2>  
            <Child3>child3 content</Child3>More text content.  
            <Child4>child4 content</Child4>  
            <Child5>child5 content</Child5>  
        </Root>  
  
Dim child3 As XElement = xmlTree.<Child3>(0)  
Dim child5 As XElement = xmlTree.<Child5>(0)  
If (child5.IsBefore(child3)) Then  
    Console.WriteLine("Child5 is before Child3")  
Else  
    Console.WriteLine("Child5 is not before Child3")  
End If  

這個範例會產生下列輸出:This example produces the following output:

Child5 is not before Child3  

備註

XContainer 會將其子節點儲存為 XNode 物件的單一連結清單。The XContainer stores its child nodes as a singly-linked list of XNode objects. 這表示 IsBefore 方法必須先將兩個節點的祖系進行比較,直到找到一般父系為止。This means that the IsBefore method must traverse the ancestors of the two nodes being compared until it finds the common parent. 然後,它必須跨越一般父系的子節點清單,以判斷兩個節點的順序是否比較。Then it must traverse the list of the common parent's child nodes to determine the order of the two nodes being compared. 因此,使用此方法可能會影響您的效能。Therefore, using this method might affect your performance.

適用於

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