grid updation

have you declare datakeyname in gridview:


DataKeyNames="classId"
                        DataSourceID="SqlDataSource1" BackColor="White" BorderColor="#E7E7FF"
                        BorderStyle="None" BorderWidth="1px" CellPadding="3" GridLines="Horizontal"
                        onpageindexchanging="gvclass_PageIndexChanging1"
                        onrowcancelingedit="gvclass_RowCancelingEdit1"
                        onrowediting="gvclass_RowEditing1" onrowupdating="gvclass_RowUpdating1"
                        onselectedindexchanging="gvclass_SelectedIndexChanging1"
                        onsorting="gvclass_Sorting">
                       
                       

class.aspx.cs



using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Drawing;


namespace ERP
{
    public partial class _class : System.Web.UI.Page
    {

        public void clear()
        {
            txtclass.Text = "";
            txtno.Text = "";
        }

        public void view1(decimal cid)
        {
            classinfo infoclass = new classinfo();
            classsp spclass = new classsp();
            infoclass = spclass.ClassViews(cid);
            txtclassname.Text = infoclass.className;
            txtno.Text = infoclass.noOfSeats.ToString();
            mvclass.SetActiveView(vclass);
        }
        public void gridfill()
        {
            classsp spclass = new classsp();
            DataTable dt = new DataTable();
            dt = spclass.ClassViewall();
            //gvclass.DataSource = dt;
            gvclass.DataBind();
        }

        public void save()
        {
            lblmsg.Text = "";
            classinfo infoclass = new classinfo();
            classsp spclass = new classsp();
            infoclass.className = txtclass.Text;
            infoclass.noOfSeats = int.Parse(txtno.Text.ToString());
            if (ViewState["classID"] == null)
            {
                int a = spclass.classAdd(infoclass);
                if (a >= 0)
                {
                    lblmsg.Text = "Saved Success";
                    lblmsg.ForeColor = Color.Green;
                    gridfill();
                    clear();
                }
                else
                {
                    lblmsg.Text = "Already Exist";
                    lblmsg.ForeColor = Color.Red;
                }
            }
            else
            {
                infoclass.classId = decimal.Parse(ViewState["classID"].ToString());
                int b = spclass.ClassEdit(infoclass);
                ViewState["classID"] = null;
                if (b >= 0)
                {
                    lblmsg.Text = "Updated";
                    lblmsg.ForeColor = Color.Green;
                    gridfill();
                    clear();
                }
                else
                {
                    lblmsg.Text = "already exist";
                    lblmsg.ForeColor = Color.Red;
                }
            }
        }
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                gridfill();
                if (gvclass.Rows.Count > 0)
                {
                    lblclass.Visible = false;
                    txtclass.Visible = false;
                    mvclass.SetActiveView(vclassgrid);
                }
                else
                {
                    mvclass.SetActiveView(vclass);
                }
            }
        }

        protected void btnsave_Click(object sender, EventArgs e)
        {
            save();
        }                
        protected void btnclear_Click(object sender, EventArgs e)
        {
            clear();
            lblmsg.Text = "";
        }

        protected void txtclass_TextChanged(object sender, EventArgs e)
        {
            classsp spclass = new classsp();
            if (txtclass.Text != string.Empty)
            {
                gvclass.DataSource = spclass.ClassGridSearch(txtclass.Text.Trim());
                gvclass.DataBind();
            }
            else
            {
                spclass.ClassViewall();
                gvclass.DataBind();
            }
        }

        protected void gvclass_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            gvclass.PageIndex = e.NewPageIndex;
            gridfill();
        }

        protected void gvclass_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
        {
            ViewState["classID"] = decimal.Parse(gvclass.DataKeys[e.NewSelectedIndex]["classId"].ToString());
            decimal d = decimal.Parse(ViewState["classID"].ToString());
            view1(d);
        }

        protected void gvclass_RowEditing(object sender, GridViewEditEventArgs e)
        {
            gvclass.EditIndex = e.NewEditIndex;
            gridfill();
        }

        protected void gvclass_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
        {
            e.Cancel = true;
            gvclass.EditIndex = -1;
            gridfill();
        }

        protected void gvclass_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
            classinfo infoclass = new classinfo();
            classsp spclass = new classsp();
            GridViewRow row = gvclass.Rows[e.RowIndex];
            infoclass.classId = decimal.Parse(gvclass.DataKeys[e.RowIndex].Value.ToString());
            infoclass.className = ((TextBox)row.FindControl("txtclassname")).Text;
            infoclass.noOfSeats = int.Parse(((TextBox)row.FindControl("txtno")).Text);
            int a = spclass.ClassEdit(infoclass);
            gvclass.EditIndex = -1;
            gridfill();
        }

        protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
        {
            lblmsg.Text = "";
            mvclass.SetActiveView(vclass);

        }
        protected void ImageButton2_Click(object sender, ImageClickEventArgs e)
        {
            lblmsg.Text = "";
            classsp spclass = new classsp();
            int a = spclass.ClassDelete(decimal.Parse(ViewState["classID"].ToString()));
            ViewState["classID"] = null;
            if (a >= 0)
            {
                lblmsg.Text = "deleted successfully";
                gridfill();
                ImageButton1.Enabled = false;
                clear();
            }
            else
            {
                lblmsg.Text = "can't delete";
                ImageButton1.Enabled = false;
            }
        }

        protected void gvclass_PageIndexChanging1(object sender, GridViewPageEventArgs e)
        {
            gvclass.PageIndex = e.NewPageIndex;
            gridfill();
        }

        protected void gvclass_SelectedIndexChanging1(object sender, GridViewSelectEventArgs e)
        {
            ViewState["classID"] = decimal.Parse(gvclass.DataKeys[e.NewSelectedIndex]["classId"].ToString());
            decimal d = decimal.Parse(ViewState["classID"].ToString());
            view1(d);
        }

        protected void gvclass_Sorting(object sender, GridViewSortEventArgs e)
        {
            classsp spclass = new classsp();
            DataTable dt = new DataTable();
            dt = spclass.ClassViewall();
            if (ViewState["sort"] == null)
            {
                dt.DefaultView.Sort = e.SortDirection + "DESC";
                gvclass.DataSource = dt;
                gvclass.DataBind();
                ViewState["sort"] = "DESC";
            }
            else
            {
                dt.DefaultView.Sort = e.SortExpression + "ASC";
                gvclass.DataSource = dt;
                gvclass.DataBind();
                ViewState["sort"] = null;
            }
        }

        protected void gvclass_RowEditing1(object sender, GridViewEditEventArgs e)
        {
            gvclass.EditIndex = e.NewEditIndex;
            gridfill();
        }

        protected void gvclass_RowCancelingEdit1(object sender, GridViewCancelEditEventArgs e)
        {
            e.Cancel = true;
            gvclass.EditIndex = -1;
            gridfill();
        }

        protected void gvclass_RowUpdating1(object sender, GridViewUpdateEventArgs e)
        {
            classinfo infoclass = new classinfo();
            classsp spclass = new classsp();
            GridViewRow row = gvclass.Rows[e.RowIndex];
            infoclass.classId = decimal.Parse(gvclass.DataKeys[e.RowIndex].Value.ToString());

            infoclass.className = ((TextBox)row.FindControl("txtICLassName")).Text;
            infoclass.noOfSeats = int.Parse(((TextBox)row.FindControl("txtISeats")).Text);
            int a = spclass.ClassEdit(infoclass);
            gvclass.EditIndex = -1;
            gridfill();         
        }
    }
}

try this:

infoclass.classId=decimal.Parse(gvclass.DataKeys[e.RowIndex].Value[classid].ToString());

and check what the value you are getting in the highlighted line

set date key name as classId  in grid
 

what is rhe data type of classid in class info

hi,

try this code in row updating

classinfo infoclass = new classinfo();
        classsp spclass = new classsp();
        GridViewRow row=gvclass.Rows.[e.RowIndex];
        infoclass.classId=decimal.Parse(gvclass.DataKeys[e.RowIndex].Value.ToString());
        infoclass.className=((TextBox)row.FindControl("txtICLassName")).Text;
        infoclass.noOfSeats=int.Parse(((TextBox)row.FindControl("txtISeats")).Text);
        int a=spclass.ClassEdit(infoclass);
        gvclass.EditIndex = -1;
        gridfill();

                        DataSourceID="SqlDataSource1" BackColor="White" BorderColor="#E7E7FF"
                        BorderStyle="None" BorderWidth="1px" CellPadding="3" GridLines="Horizontal"
                        onpageindexchanging="gvclass_PageIndexChanging1"
                        onrowcancelingedit="gvclass_RowCancelingEdit1"
                        onrowediting="gvclass_RowEditing1" onrowupdating="gvclass_RowUpdating1"
                        onselectedindexchanging="gvclass_SelectedIndexChanging1"
                        onsorting="gvclass_Sorting">
                       
                       
                       
                                                            SortExpression="classId" Visible="False" />
                           
                                       
                                           
                                       
                               
                                   
                               
                           
                           
                               
                                   
                               
                               
                                   
                               
                           
                           
                           
                       
                       
                       
                       
                       
                   
                                            SelectCommand="SELECT [classId], [className], [noOfSeats] FROM [tbl_Class]">
                   

plz share your grid aspx design code