Convert JSON String to DataTable in ASP.Net

First of all you need to create an "ASP.NET Empty Web Site". Then use the following procedure.

Step 1

Create a ConvertJsonStringToDataTable class in the App_Code folder and provide the following:

using System;
using System.Collections.Generic;
using System.Data;
using System.Text.RegularExpressions;

public class ConvertJsonStringToDataTable
{
   public DataTable JsonStringToDataTable(string jsonString)
   {
      DataTable dt = new DataTable();
      string[] jsonStringArray = Regex.Split(jsonString.Replace("[", "").Replace("]", ""), "},{");
      List<string> ColumnsName = new List<string>();
      foreach (string jSA in jsonStringArray)
      {
         string[] jsonStringData = Regex.Split(jSA.Replace("{", "").Replace("}", ""), ",");
         foreach (string ColumnsNameData in jsonStringData)
         {
            try
            {
               int idx = ColumnsNameData.IndexOf(":");
               string ColumnsNameString = ColumnsNameData.Substring(0, idx - 1).Replace("\"", "");
               if (!ColumnsName.Contains(ColumnsNameString))
               {
                  ColumnsName.Add(ColumnsNameString);
               }
            }
            catch (Exception ex)
            {
               throw new Exception(string.Format("Error Parsing Column Name : {0}", ColumnsNameData));
            }
         }
         break;
      }
      foreach (string AddColumnName in ColumnsName)
      {
         dt.Columns.Add(AddColumnName);
      }
      foreach (string jSA in jsonStringArray)
      {
         string[] RowData = Regex.Split(jSA.Replace("{", "").Replace("}", ""), ",");
         DataRow nr = dt.NewRow();
         foreach (string rowData in RowData)
         {
            try
            {
               int idx = rowData.IndexOf(":");
               string RowColumns = rowData.Substring(0, idx - 1).Replace("\"", "");
               string RowDataString = rowData.Substring(idx + 1).Replace("\"", "");
               nr[RowColumns] = RowDataString;
            }
            catch (Exception ex)
            {
               continue;
            }
         }
         dt.Rows.Add(nr);
      }
      return dt;
   }
}

Step 2

Write the following design code:

<asp:Label ID="ui_lbl_JsonString" runat="server"></asp:Label>
<br />
<br />
<asp:Button ID="ui_btn_Convert1" runat="server" Text="Manually Convert into DataTable" OnClick="ui_btn_Convert1_Click" />
<asp:Button ID="ui_btn_Reload" runat="server" Text="Reload" OnClick="ui_btn_Reload_Click" />
<br />
<br />
<asp:GridView ID="ui_grdVw_EmployeeDetail1" runat="server" Width="50%" HeaderStyle-CssClass="pageheading"></asp:GridView>

Step 3

Now, open the Deafult.asps.cs then write the following code:

using System;
using System.Data;
using System.IO;

public partial class _Default : System.Web.UI.Page
{
   #region Global Variable
   DataTable dt;
   string JsonString = string.Empty;
   ConvertJsonStringToDataTable jDt = new ConvertJsonStringToDataTable();
   #endregion

protected void Page_Load(object sender, EventArgs e)
{
   if (!IsPostBack)
   {
      string FileName = "JSONString.txt";
      var stream = File.OpenText(Server.MapPath(FileName));
      JsonString = stream.ReadToEnd();
      ui_lbl_JsonString.Text = JsonString;
   }

   protected void ui_btn_Convert1_Click(object sender, EventArgs e)
   {
      JsonString = ui_lbl_JsonString.Text;
      dt = jDt.JsonStringToDataTable(JsonString);
      ui_grdVw_EmployeeDetail1.DataSource = dt;
      ui_grdVw_EmployeeDetail1.DataBind();
   }

   protected void ui_btn_Reload_Click(object sender, EventArgs e)
   {
      Response.Redirect(Request.RawUrl);
   }
}

Step 4

Press F5, run the 

Now, convert the JSON string to DataTable using the newtonsoft DLL.

Step 1

Download the Newtonsoft DLL and move it to the ASP.Net project's bin folder.

Step 2

Then, Open the Deafult.aspx page and write the following design code:

<asp:Button ID="ui_btn_Convert2" runat="server" Text="Newtonsoft Convert into DataTable" OnClick="ui_btn_Convert2_Click" />
<br />
<br />
<asp:GridView ID="ui_grdVw_EmployeeDetail2" runat="server" Width="50%" HeaderStyle-CssClass="pageheading"></asp:GridView>

Step 3

Now, write the following code in Default.aspx.cs:

using this namespace.

using Newtonsoft.Json;

 And then:

protected void ui_btn_Convert2_Click(object sender, EventArgs e)
{
   JsonString = ui_lbl_JsonString.Text;
   dt = (DataTable)JsonConvert.DeserializeObject(JsonString, (typeof(DataTable)));
   ui_grdVw_EmployeeDetail2.DataSource = dt;
   ui_grdVw_EmployeeDetail2.DataBind();
}

Run the project and click on the Newtonsoft Convert to DataTable.

 

In the preceding code, I convert the JSON String to DataTable.

I have attached the sample project for this, download and see how it works.

Thank you.