Sub Total & Grand Total in Dataset(Datatables) using Group Names C#

If you have Linkbutton in asp.net ,you did't get Total ,sub Total in Row Data Bound if you using Model Popup.So you need to get  subtotal,grand total in Datatable itself.The given below example give you the Group Names{ProjectName} based total,subtotal using Linq.

 using System;  
 using System.Collections.Generic;  
 using System.ComponentModel;  
 using System.Data;  
 using System.Drawing;  
 using System.Text;  
 using System.Windows.Forms;  
 //added namespace  
 using System.Linq;  
 namespace testDatatablesum  
 {  
   public partial class Form1 : Form  
   {  
     public Form1()  
     {  
       InitializeComponent();  
     }  
     private DataTable getdata()  
     {  
       DataTable dt = new DataTable();  
       dt.Columns.Add("ProjectName");  
       dt.Columns.Add("Source");  
       dt.Columns.Add("SourceAmount");  
       // Add Rows  
       DataRow rowA1 = dt.NewRow();  
       rowA1["ProjectName"] = "A";  
       rowA1["Source"] = "ABC";  
       rowA1["SourceAmount"] = "10000";  
       dt.Rows.Add(rowA1);  
       DataRow rowA2 = dt.NewRow();  
       rowA2["ProjectName"] = "A";  
       rowA2["Source"] = "XYZ";  
       rowA2["SourceAmount"] = "50200";  
       dt.Rows.Add(rowA2);  
       DataRow rowA3 = dt.NewRow();  
       rowA3["ProjectName"] = "A";  
       rowA3["Source"] = "DFG";  
       rowA3["SourceAmount"] = "27000";  
       dt.Rows.Add(rowA3);  
       DataRow rowB1 = dt.NewRow();  
       rowB1["ProjectName"] = "B";  
       rowB1["Source"] = "LMN";  
       rowB1["SourceAmount"] = "12990";  
       dt.Rows.Add(rowB1);  
       DataRow rowB2 = dt.NewRow();  
       rowB2["ProjectName"] = "B";  
       rowB2["Source"] = "PQR";  
       rowB2["SourceAmount"] = "14000";  
       dt.Rows.Add(rowB2);  
       DataRow rowC1 = dt.NewRow();  
       rowC1["ProjectName"] = "C";  
       rowC1["Source"] = "KLM";  
       rowC1["SourceAmount"] = "10000";  
       dt.Rows.Add(rowC1);  
       return dt;  
     }  
     private void button1_Click(object sender, EventArgs e)  
     {  
       DataTable dt = new DataTable();  
       dt= getdata();  
       // Find distinct projects  
       var distinctProjects = (from r in dt.AsEnumerable()  
                   select r["ProjectName"]).Distinct().OrderBy(project => project);  
       // Get all amounts to tally later for the All Total entry  
       var allEntries = from r in dt.AsEnumerable()  
               select r["SourceAmount"];  
       // Loop through distinct project list and add project subtotal row to table  
       foreach (var p in distinctProjects)  
       {  
         var amt = from r in dt.AsEnumerable()  
              where r["ProjectName"] == p  
              select r["SourceAmount"];  
         DataRow dr = dt.NewRow();  
         dr["ProjectName"] = p + " Sub Total:";  
         dr["SourceAmount"] = amt.Sum(x => Convert.ToDecimal(x));  
         dt.Rows.Add(dr);  
       }  
       // Sort table so the sub totals fall under the project it belongs to  
       DataView dv = dt.DefaultView;  
       dv.Sort = "ProjectName ASC, Source ASC";  
       dt = dv.ToTable();  
       // Create and add the final total row  
       DataRow finalTotal = dt.NewRow();  
       finalTotal["ProjectName"] = "All Total:";  
       finalTotal["SourceAmount"] = allEntries.Sum(x => Convert.ToDecimal(x));  
       dt.Rows.Add(finalTotal);  
       // Display correct results with message box  
       foreach (DataRow r in dt.Rows)  
       {  
         MessageBox.Show(  
           r["ProjectName"].ToString() + "  " +  
           r["Source"].ToString() + "  " +  
           r["SourceAmount"].ToString()  
         );  
       }  
     }  
   }  
 }  

Output:
Dataset Input:

Dataset OUTPUT: