row command in griedview asp.net C#

*********RowCommand_event of Gridview*************
Step1: Add the gridview in your .aspx page.
<div>
    <asp:GridView ID="GridView1" runat="server"  AutoGenerateColumns="false"          
             DataKeyNames="EmpID"onrowcommand="GridView1_RowCommand">
          <Columns>
            <asp:BoundField DataField="EMPID" HeaderText="EmployeeID" />
         <asp:BoundField DataField="FirstName" HeaderText="FirstName" />
            <asp:BoundField DataField="LastName" HeaderText="LastName" />
            <asp:BoundField DataField="Address" HeaderText="Address" />
            <asp:BoundField DataField="Mobile" HeaderText="Mobile" />
            <asp:TemplateField>
            <ItemTemplate>
            <asp:Button ID="btnSelect" runat="server" Text="Select" CommandName="Select" CommandArgument='<%# Eval("Mobile") %>' />
            </ItemTemplate>
            </asp:TemplateField>
          </Columns>
        </asp:GridView>


        <asp:Label ID="lblMessage" runat="server"></asp:Label>   
    
        <asp:TextBox ID="txtMobile" runat="server"></asp:TextBox>
    </div>


step 2:- your .aspx.cs page.


NOTE:- this is my connection string which is using in below coding you can use your own to modify it in your web.config file.
My connectiion string is.
"

<connectionStrings>
    <add name="mycon" connectionString="data source=SHIVAMGUPTA; initial catalog=operation; integrated security=true;" providerName="System.Data.SqlClient"/>
  </connectionStrings>

"
**********************your code behind part.*********************

public partial class SelectGridColumn : System.Web.UI.Page
{


SqlConnection con;
    protected void Page_Load(object sender, EventArgs e)
    {
        string conection;
        conection = System.Configuration.ConfigurationManager.ConnectionStrings["mycon"].ConnectionString.ToString();
        con = new SqlConnection(conection);
        if (!IsPostBack)
        {
            FillGrid();
        }
    }




    protected void FillGrid()
    {
        SqlCommand cmd = new SqlCommand("select * from employee", con);
        con.Open();
        GridView1.DataSource = cmd.ExecuteReader();
        GridView1.DataBind();
        con.Close();
    }


    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Select")
        {
            txtMobile.Text = Convert.ToString(e.CommandArgument);
            lblMessage.Text = "this the mobile no of selected row!";
        }
    }

}