XNode.IsBefore(XNode) Method

Reference

Definition

Namespace:: System.Xml.Linq

Assemblies:: System.Xml.Linq.dll, System.Xml.XDocument.dll

Assemblies:: netstandard.dll, System.Xml.XDocument.dll

Assembly:: System.Xml.XDocument.dll

Assembly:: System.Xml.Linq.dll

Assembly:: netstandard.dll

Source:: XNode.cs

Source:: XNode.cs

Source:: XNode.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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);

public bool IsBefore(System.Xml.Linq.XNode? node);

member this.IsBefore : System.Xml.Linq.XNode -> bool

Public Function IsBefore (node As XNode) As Boolean

Parameters

node: XNode

The XNode to compare for document order.

Returns

Boolean

true if this node appears before the specified node; otherwise false.

Examples

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

This example produces the following output:

Child5 is not before Child3

Remarks

The XContainer stores its child nodes as a singly-linked list of XNode objects. This means that the IsBefore method must traverse the ancestors of the two nodes being compared until it finds the common parent. Then it must traverse the list of the common parent's child nodes to determine the order of the two nodes being compared. Therefore, using this method might affect your performance.

Applies to

Product	Versions
.NET	Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1
UWP	10.0

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