Add Object to JSON Array using C# and VB.Net

Hi Amitabha,

First you need to Deserialize the JSON string to class object after that you need to add necessary data to class object and then convert the class object to JSON.

Please refer below sample.

Namespace

C#

using System.Web.Script.Serialization;

VB.Net

Imports System.Web.Script.Serialization

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    List<Datum> datum = new List<Datum>();
    datum.Add(new Datum
    {
        num = 1,
        hsn_sc = "123",
        desc = "Test",
        uqc = "OTH",
        qty = 0,
        val = 1481657.69,
        txval = 1322908.70,
        iamt = 37091.69,
        camt = 60828.65,
        samt = 60828.65,
        csamt = 0
    });

    Hsn hsn = new Hsn();
    hsn.data = datum;

    Root root = new Root();
    root.hsn = hsn;
    string json = new JavaScriptSerializer().Serialize(root);

    // Adding new Datum to existing json.
    Root data = new JavaScriptSerializer().Deserialize<Root>(json);
    data.hsn.data.Add(new Datum
    {
        num = 2,
        hsn_sc = "1234",
        desc = "Test 1",
        uqc = "OTH 1",
        qty = 0,
        val = 1481657.69,
        txval = 1322908.70,
        iamt = 37091.69,
        camt = 60828.65,
        samt = 60828.65,
        csamt = 0
    });

    json = new JavaScriptSerializer().Serialize(data);
}

public class Root
{
    public Hsn hsn { get; set; }
}

public class Hsn
{
    public List<Datum> data { get; set; }
}
public class Datum
{
    public int num { get; set; }
    public string hsn_sc { get; set; }
    public string desc { get; set; }
    public string uqc { get; set; }
    public int qty { get; set; }
    public double val { get; set; }
    public double txval { get; set; }
    public double iamt { get; set; }
    public double camt { get; set; }
    public double samt { get; set; }
    public double csamt { get; set; }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim datum As List(Of Datum) = New List(Of Datum)()
    datum.Add(New Datum With {
        .num = 1,
        .hsn_sc = "123",
        .desc = "Test",
        .uqc = "OTH",
        .qty = 0,
        .val = 1481657.69,
        .txval = 1322908.7,
        .iamt = 37091.69,
        .camt = 60828.65,
        .samt = 60828.65,
        .csamt = 0
    })
    Dim hsn As Hsn = New Hsn()
    hsn.data = datum
    Dim root As Root = New Root()
    root.hsn = hsn
    Dim json As String = New JavaScriptSerializer().Serialize(root)
    Dim data As Root = New JavaScriptSerializer().Deserialize(Of Root)(json)
    data.hsn.data.Add(New Datum With {
        .num = 2,
        .hsn_sc = "1234",
        .desc = "Test 1",
        .uqc = "OTH 1",
        .qty = 0,
        .val = 1481657.69,
        .txval = 1322908.7,
        .iamt = 37091.69,
        .camt = 60828.65,
        .samt = 60828.65,
        .csamt = 0
    })
    json = New JavaScriptSerializer().Serialize(data)
End Sub

Public Class Root
    Public Property hsn As Hsn
End Class

Public Class Hsn
    Public Property data As List(Of Datum)
End Class

Public Class Datum
    Public Property num As Integer
    Public Property hsn_sc As String
    Public Property desc As String
    Public Property uqc As String
    Public Property qty As Integer
    Public Property val As Double
    Public Property txval As Double
    Public Property iamt As Double
    Public Property camt As Double
    Public Property samt As Double
    Public Property csamt As Double
End Class

Generated Json

{
  "hsn": {
    "data": [
      {
        "num": 1,
        "hsn_sc": "123",
        "desc": "Test",
        "uqc": "OTH",
        "qty": 0,
        "val": 1481657.69,
        "txval": 1322908.7,
        "iamt": 37091.69,
        "camt": 60828.65,
        "samt": 60828.65,
        "csamt": 0
      },
      {
        "num": 2,
        "hsn_sc": "1234",
        "desc": "Test 1",
        "uqc": "OTH 1",
        "qty": 0,
        "val": 1481657.69,
        "txval": 1322908.7,
        "iamt": 37091.69,
        "camt": 60828.65,
        "samt": 60828.65,
        "csamt": 0
      }
    ]
  }
}