DataGridView column footer c#.net winforms

Question

Is there a way to add a column footer in a datagridview which is not databound? I am using it to take user input for adding inventory. Currently I am using a label to display the total, but I want to change it to footer if possible.

Answer 1

I ran into the same problem previously and after a long search I realised;

1. Winform Datagridview do not support adding footer to it.

2. I tried adding an extra row that could hold the summary but still did not work out fine.

3. You can create a user control that has two grids and with the lower grid holding the summary.

Solution--

4. My solution that used data binding.(1)-I Create an abstract object Item with (Name, Cost) properties.(2)-I Create a Concrete item i.e ConcItem that inherit Item(3)-I create a footer item i.e FooterItem that also inherits Item(4)-A collection of Items i.e ItemList where you instantiate the footer item.(5) Finally, just before you do data binding call the method that adds the footer item.

   public abstract class Item
   {
     public virtual string Name { get; set; }
     public virtual int Cost { get; set; }
   }
   public  class ConcItem:Item
   {
     public override string Name { get; set; }
     public override int Cost { get; set; }        
   }
   public  class FooterItem:Item 
   {
     public override string Name { get { return "Total"; } }
     public override int Cost { get; set; }
   }
   public class ItemList : List<Item>
   {
     private Item _footer;
   
     public void SetFooter()
     {
       _footer = new FooterItem();            
       foreach (var item in this)
       {
         _footer.Cost += item.Cost;              
       }
       this.Add(_footer);
     }
   }
   
   
   public partial class Form1 : Form
   {
     Item _item;
     ItemList _itemList;
     public Form1()
     {
       InitializeComponent();
       dgv.DataBindingComplete += dgv_DataBindingComplete;
       _itemList = new ItemList();
   
       SetSampleData();
     }
     private void SetSampleData()
     {
       _item = new ConcItem();
       _item.Name = "Book";
       _item.Cost = 250;
       _itemList.Add(_item);
   
       _item = new ConcItem();
       _item.Name = "Table";
       _item.Cost = 500;
       _itemList.Add(_item);
   
       _item = new ConcItem();
       _item.Name = "PC";
       _item.Cost = 700;
       _itemList.Add(_item);
   
       dgv.DataSource = null;
       _itemList.SetFooter();  //Add the footer item b4  data binding
       dgv.DataSource = _itemList;
     }
     void dgv_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
     {
       //If you want to do some formating on the footer row
       int rowIndex = dgv.Rows.GetLastRow(DataGridViewElementStates.Visible);
       if (rowIndex <= 0)
       {
         return;
       }
       dgv.Rows[rowIndex].DefaultCellStyle.BackColor = Color.Red;
       dgv.Rows[rowIndex].DefaultCellStyle.SelectionBackColor = Color.Red;        
       dgv.Rows[rowIndex].DefaultCellStyle.Font = new Font("Microsoft Sans Serif", 12f,    FontStyle.Bold);
     }
   }
   

Answer 2

In one of my applications I solved it by taking advantage of NewRow of DataGridView like this.

using System;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            this.dataGridView1.CellFormatting += dataGridView1_CellFormatting;
            this.dataGridView1.CellValueChanged += dataGridView1_CellValueChanged;
        }

        void dataGridView1_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex != this.dataGridView1.NewRowIndex && e.ColumnIndex == 2)
            {
                this.dataGridView1.InvalidateRow(this.dataGridView1.NewRowIndex);
            }
        }

        void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if (e.RowIndex == this.dataGridView1.NewRowIndex)
            {
                e.CellStyle.Font = new Font(e.CellStyle.Font, FontStyle.Bold);
                e.CellStyle.ForeColor = Color.Red;
                switch (e.ColumnIndex)
                {
                    case 0:
                        e.Value = "Total";
                        break;

                    case 2:
                        var sum = 0.0d;
                        for (int i = 0; i < this.dataGridView1.NewRowIndex; i++)
                        {
                            var value = this.dataGridView1[2, i].Value;
                            if (value is double)
                            {
                                sum += ((double)value);
                            }
                        }
                        e.Value = Math.Round(sum, 2);
                        break;
                    // Single line version of case 2 would be
                    // e.Value = this.dataGridView1.Rows.Cast<DataGridViewRow>().Where(a => a.Index != a.DataGridView.NewRowIndex).Select(a => (double)a.Cells[2].Value).Sum().ToString("N2");
                }
            }
        }

    }
}

Here is live screenshot of how it works.