How to convert datatable to json string using json.net?

string json = JsonConvert.SerializeObject(table, Formatting.Indented);

Edit: You don't need indented formatting, of course, but it makes it nice and readable.

Maybe it could help

Original version

public static class DataTableToJson{    public static JArray ToJson(this System.Data.DataTable source)    {        JArray result = new JArray();        JObject row;        foreach (System.Data.DataRow dr in source.Rows)        {            row = new JObject();            foreach (System.Data.DataColumn col in source.Columns)            {                row.Add(col.ColumnName.Trim(), JToken.FromObject(dr[col]));            }            result.Add(row);        }        return result;    }}

Edited Version

There is a intermediate step because I needed to have a dictionary

public static IEnumerable<Dictionary<string, object>> ToDictionary(this DataTable table){    string[] columns = table.Columns.Cast<DataColumn>().Select(c=>c.ColumnName).ToArray();    IEnumerable<Dictionary<string, object>>  result = table.Rows.Cast<DataRow>()            .Select(dr => columns.ToDictionary(c => c, c=> dr[c]));    return result;}

You can add JsonConverter.SerializeObject(result);, or another json serializer to get json string.

This is similar to @Hasan Javaid post

Check this.

private static string DataTableToJson(DataTable dataTable){    JavaScriptSerializer serializer = new JavaScriptSerializer();    var rows = (from DataRow d in dataTable.Rows        select dataTable.Columns.Cast<DataColumn>().ToDictionary(col => col.ColumnName, col => d[col])).ToList();    rows.AddRange(from DataRow d in dataTable.Rows        select dataTable.Columns.Cast<DataColumn>().ToDictionary(col => col.ColumnName, col => d[col]));    return serializer.Serialize(rows);}