GridView Operation in as.net

...............................................................aspx..............................................................................

<div class="GridviewDiv">
<asp:GridView runat="server" ID="gvDetails" ShowFooter="true" AllowPaging="true" PageSize="10" AutoGenerateColumns="false" DataKeyNames="productid,productname" OnPageIndexChanging="gvDetails_PageIndexChanging" OnRowCancelingEdit="gvDetails_RowCancelingEdit"
OnRowEditing="gvDetails_RowEditing" OnRowUpdating="gvDetails_RowUpdating" OnRowDeleting="gvDetails_RowDeleting" OnRowCommand ="gvDetails_RowCommand" >
<HeaderStyle CssClass="headerstyle" />
<Columns>
<asp:BoundField DataField="productid" HeaderText="Product Id" ReadOnly="true" />
<asp:TemplateField HeaderText="Product Name">
<ItemTemplate>
<asp:Label ID="lblProductname" runat="server" Text='<%# Eval("productname")%>'/>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtProductname" runat="server" Text='<%# Eval("productname")%>'/>
</EditItemTemplate>
<FooterTemplate>
<asp:TextBox ID="txtpname" runat="server" />
</FooterTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText = "Price">
<ItemTemplate>
<asp:Label ID="lblPrice" runat="server" Text='<%# Eval("price")%>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtProductprice" runat="server" Text='<%# Eval("price")%>'/>
</EditItemTemplate>
<FooterTemplate>
<asp:TextBox ID="txtprice" runat="server" />
<asp:Button ID="btnAdd" CommandName="AddNew" runat="server" Text="Add" />
</FooterTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" ShowDeleteButton="True" />
</Columns>
</asp:GridView>
<asp:Label ID="lblresult" runat="server"></asp:Label>
</div>


..........................................................cs file ......................................................
protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindGridview();
        }
    }
    protected void BindGridview()
    {
        DataSet ds = new DataSet();
        using (SqlConnection con = new SqlConnection("Data Source=AKRAM-PC;Integrated Security=true;Initial Catalog=Ekram"))
        {
            con.Open();
            SqlCommand cmd = new SqlCommand("crudoperations", con);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@status", "SELECT");
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            con.Close();
            if (ds.Tables[0].Rows.Count > 0)
            {
                gvDetails.DataSource = ds;
                gvDetails.DataBind();
            }
            else
            {
                ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());
                gvDetails.DataSource = ds;
                gvDetails.DataBind();
                int columncount = gvDetails.Rows[0].Cells.Count;
                gvDetails.Rows[0].Cells.Clear();
                gvDetails.Rows[0].Cells.Add(new TableCell());
                gvDetails.Rows[0].Cells[0].ColumnSpan = columncount;
                gvDetails.Rows[0].Cells[0].Text = "No Records Found";
            }
        }
    }
    protected void gvDetails_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName.Equals("AddNew"))
        {
            TextBox txtname = (TextBox)gvDetails.FooterRow.FindControl("txtpname");
            TextBox txtprice = (TextBox)gvDetails.FooterRow.FindControl("txtprice");
            crudoperations("INSERT", txtname.Text, txtprice.Text, 0);
        }
    }
    protected void gvDetails_RowEditing(object sender, GridViewEditEventArgs e)
    {
        gvDetails.EditIndex = e.NewEditIndex;
        BindGridview();
    }
    protected void gvDetails_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        gvDetails.EditIndex = -1;
        BindGridview();
    }
    protected void gvDetails_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        gvDetails.PageIndex = e.NewPageIndex;
        BindGridview();
    }
    protected void gvDetails_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        int productid = Convert.ToInt32(gvDetails.DataKeys[e.RowIndex].Values["productid"].ToString());
        TextBox txtname = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtProductname");
        TextBox txtprice = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtProductprice");
        crudoperations("UPDATE", txtname.Text, txtprice.Text, productid);
    }
    protected void gvDetails_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        int productid = Convert.ToInt32(gvDetails.DataKeys[e.RowIndex].Values["productid"].ToString());
        string productname = gvDetails.DataKeys[e.RowIndex].Values["productname"].ToString();
        crudoperations("DELETE", productname, "", productid);
    }
    protected void crudoperations(string status, string productname, string price, int productid)
    {
        using (SqlConnection con = new SqlConnection("Data Source=AKRAM-PC;Integrated Security=true;Initial Catalog=Ekram"))
        {
            con.Open();
            SqlCommand cmd = new SqlCommand("crudoperations", con);
            cmd.CommandType = CommandType.StoredProcedure;
            if (status == "INSERT")
            {
                cmd.Parameters.AddWithValue("@status", status);
                cmd.Parameters.AddWithValue("@productname", productname);
                cmd.Parameters.AddWithValue("@price", price);
            }
            else if (status == "UPDATE")
            {
                cmd.Parameters.AddWithValue("@status", status);
                cmd.Parameters.AddWithValue("@productname", productname);
                cmd.Parameters.AddWithValue("@price", price);
                cmd.Parameters.AddWithValue("@productid", productid);
            }
            else if (status == "DELETE")
            {
                cmd.Parameters.AddWithValue("@status", status);
                cmd.Parameters.AddWithValue("@productid", productid);
            }
            cmd.ExecuteNonQuery();
            lblresult.ForeColor = Color.Green;
            lblresult.Text = productname + " details " + status.ToLower() + "d successfully";
            gvDetails.EditIndex = -1;
            BindGridview();
        }
    }