Imports System

Imports System.Collections.Generic

Imports System.Collections

Imports System.IO

Imports System.Text

Imports System.Collections.ObjectModel

Imports System.Linq

Imports System.Reflection

​

Imports System.Xml.Serialization

Imports System.Xml

Imports System.Xml.Linq

Imports System.Xml.XPath

Imports System.Xml.Schema

​

' https://stackoverflow.com/questions/70002031/search-string-in-value-and-get-attribute-value-in-linq-to-xml-in-vb-net

​

Public Module Module1

    Public Sub Main()

        Dim xml as String = GetXml()

​

        Dim xml_Doc = XDocument.Parse(xml)

​

        Dim sampleText = "sample text 1"

        Dim search_result = 

            (From c In xml_Doc.Descendants("catalog")

            From v in c.Elements("val")

            Where v.Value = sampleText

            Select New With {.index = v.Attribute("index").Value, .name = c.Attribute("name").Value })

        For Each s In search_result

            Console.WriteLine("index:{0} , name:{1}", s.index, s.name)

        Next

    End Sub

​

    Function GetXml() As String

            Dim xml as String = <list>

<catalog index="1" name="n1">

    <val index="1">sample text 1</val>

    <val index="2">sample text 2</val>

    <val index="3">sample text 3</val>

</catalog>

<catalog index="2" name="n2">

    <val index="1">sample text 0</val>

    <val index="2">sample text 2</val>

    <val index="3">sample text 3</val>

    <val index="4">sample text 1</val>

    <val index="5">sample text 5</val>

    <val index="6">sample text 6</val>

</catalog>

<catalog index="3" name="n3">

    <val index="1">sample text 8</val>

    <val index="2">sample text 9</val>

    <val index="3">sample text 10</val>

</catalog>

</list>.ToString

        Return xml

    End Function

End Module

​

    Public Module XmlSerializationHelper

        <System.Runtime.CompilerServices.Extension> _

        Public Function LoadFromXML(Of T)(xmlString As String) As T

            Using reader As New StringReader(xmlString)

                Return DirectCast(New XmlSerializer(GetType(T)).Deserialize(reader), T)

            End Using

        End Function

​

        <System.Runtime.CompilerServices.Extension> _

        Public Function GetXml(Of T)(obj As T, Optional omitStandardNamespaces As Boolean = False) As String

            Dim ns As XmlSerializerNamespaces = Nothing

            If omitStandardNamespaces Then

                ns = New XmlSerializerNamespaces()

                    ' Disable the xmlns:xsi and xmlns:xsd lines.

                ns.Add("", "")

            End If

            Return obj.GetXml(ns)

        End Function

​

        <System.Runtime.CompilerServices.Extension> _

        Public Function GetXml(Of T)(obj As T, ns as XmlSerializerNamespaces) As String

            Using textWriter = New StringWriter()

                Dim settings = New XmlWriterSettings() With { _

                    .Indent = True _

                }

                ' For cosmetic purposes.

                Using xmlWriter = System.Xml.XmlWriter.Create(textWriter, settings)

                    Dim serializer as New XmlSerializer(obj.GetType()) 

                    serializer.Serialize(xmlWriter, obj, ns)

                End Using

                Return textWriter.ToString()

            End Using

        End Function

​

        <System.Runtime.CompilerServices.Extension> _

        Public Function GetOuterXml(node as XmlNode, Optional indent as Boolean = true) as String

            Using textWriter = New StringWriter()

                ' For cosmetic purposes.

                Dim settings = New XmlWriterSettings() With { _

                    .Indent = indent, _

                    .OmitXmlDeclaration = true _

                }

                Using xmlWriter = System.Xml.XmlWriter.Create(textWriter, settings)

                    node.WriteTo(xmlWriter)

                End Using

                Return textWriter.ToString()

            End Using       

        End Function

    End Module