Imports System

Imports System.Linq

Imports System.Collections

Imports System.Collections.Generic

Imports System.Data

Imports System.IO

Imports System.Globalization

Imports System.Reflection

Imports System.ComponentModel.DataAnnotations

Imports System.Xml.Linq

Imports System.Xml

Imports Microsoft.VisualBasic

​

Imports Newtonsoft.Json

Imports Newtonsoft.Json.Linq

Imports Newtonsoft.Json.Converters

Imports Newtonsoft.Json.Serialization

​

Imports NUnit.Framework

​

' https://stackoverflow.com/questions/68643346/adding-jobejcts-to-a-jarray-vb-net

​

Public Module DataTableJsonExtensions

    ' Serialize all the columns of the table to an Orderlines array

    Public Function ToOrderlines(ByVal table As DataTable) As JArray

        Return ToOrderlines(table, table.Columns.Cast(Of DataColumn).Select(Function(c) c.ColumnName).ToArray())

    End Function

​

    ' Serialize the selected columns of the table to an Orderlines array with the specified culture and formats (if any)

    Public Function ToOrderlines(ByVal table As DataTable, ByVal columns() As String, Optional ByVal culture As CultureInfo = Nothing, Optional ByVal formats As IDictionary(Of String, String) = Nothing) As JArray

        culture = If (IsNothing(culture), CultureInfo.InvariantCulture, culture)

        Dim array as JArray = New JArray

        For Each row As DataRow In table.Rows

            Dim obj As JObject = new JObject (

                new JProperty("Orderlines", 

                    New JObject(columns.Select(Function(c) New JProperty(c, String.Format(culture, If(Not IsNothing(formats) AndAlso formats.ContainsKey(c), formats(c), "{0}"), row(c)))))

                )

            )

            array.add(obj)

        Next row

        Return array

    End Function

End Module

​

Public Module TestClass 

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    Friend Sub Test()

        Dim table As DataTable = New DataTable() 

​

        ' You need to show the contents of table for us to help you further

        ' I filled the table with dummy values corresponding to your required JSON.

        table.Columns.Add("Item", GetType(string))

        table.Columns.Add("Quantity", GetType(double))

        table.Columns.Add("Amount", GetType(decimal))

        table.Columns.Add("foo", GetType(decimal))

        Dim newRow As DataRow = table.NewRow()

        newRow("Item") = "Table"

        newRow("Quantity") = 5

        newRow("Amount") = 50

        table.Rows.Add(newRow)

        ' End of code I added to initialize table

​

        Dim formats = New Dictionary(Of String, String) From {{"Amount", "{0}$"}}

        Dim myArray as JArray = DataTableJsonExtensions.ToOrderlines(table, {"Item", "Quantity", "Amount"}, Nothing, formats)

​

        Console.WriteLine("Orderlines for the three columns of the table with Amount formatting:")

        Console.WriteLine(myArray)

​

        Console.WriteLine("Default Orderlines for the entire table:")

        Console.WriteLine(DataTableJsonExtensions.ToOrderlines(table))

​

        Console.WriteLine("Orderlines for the three columns of the table:")

        Console.WriteLine(DataTableJsonExtensions.ToOrderlines(table, {"Item", "Quantity", "Amount"}))

​

​

    End Sub 

End Module

​

Public Module Module1   

    Public Sub Main()

        Console.WriteLine("Environment version: " & Environment.Version.ToString())

        Console.WriteLine("Json.NET version: " & GetType(JsonSerializer).Assembly.FullName)

        Console.WriteLine("")

​

        Try

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            TestClass.Test()

​

        Catch ex as Exception

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        Console.WriteLine("Unhandled exception: ")

        Console.WriteLine(ex)

        Throw

​

        End Try

    End Sub 

End Module

​