Deleting a Record by using RowCommand

Look at given point:

• RowCommand is one of the event to Gridveiw.
  
  
• This event fires whenever an action performed(Ex: button is clicked ) on Gridveiw control.
  
  
• To perform any operations with rowcommand in Gridveiw we need to use a property known as “commandname”.
  
  
• CommandName property is used to a button control.
  
  Example: commandname=”abc”.
  
  
• In the above line abc is commandname.
  
  
• Utilization of a commandname in itemtemplate for button is shown below.
  
  
  
  
• Now why commandname?

CommandName is used to differentiate two button type controls within Gridveiw as shown below.

Observe the following snippet:



For the above code we will get the following design:



Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;

namespace WebApplication1
{
    public partial class WebForm2 : System.Web.UI.Page
    {
        SqlConnection con = new SqlConnection("server=.;database=abc;trusted_connection=true");
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                bind();
            }

        }
        public void bind()
        {
            SqlCommand cmd = new SqlCommand("select * from employee", con);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds, "con");
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }

        protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {

            if (e.CommandName == "comdel")
            {

                int l = Convert.ToInt32(e.CommandArgument);
                con.Open();
                SqlCommand cmd = new SqlCommand("delete from employee where eno=@a", con);
                cmd.Parameters.AddWithValue("@a", l);
                int i = cmd.ExecuteNonQuery();
                if (i == 1)
                {
                    Response.Write("Record deleted");
                    bind();
                }
                else
                {
                    Response.Write("Recodrd not deleted...");
                }

                Page_Load(sender, e);
            }
        }
    }
}

Explanation on e.commandargument:

In the above code I used the following line in rowcommand event.

if (e.CommandName == "comdel")
{

   int l = Convert.ToInt32(e.CommandArgument);
   …..
   …
   …
}

e.commandargument specifies the employee number. Observe the following aspx code snippet.


If still any doubts plzz feel free to ask.

Thank you.