jabby I know you are a chinese citizen
(I got it from you code this.dataSet21.Locale = new
System.Globalization.CultureInfo("zh-CN");)
and I'm a iranian,now just at this time there is a football match between
Korea-Republic and Iran and the winner will face china
now I am giving up everything for watching this football match,
Hope Iran wins......
(Moderators,excuse me for this discussion!).

--------------------------------------------
Mehdi.

Hehe,I hopes Iran will win too!Hope so!

So there's my code after modified:
---------------------------------
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

namespace TestDelDataset
{
public class WebForm1 : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DataGrid DataGrid1;
        protected SqlDataAdapter adapter;
        protected SqlConnection myConnection;
        protected DataSet ds;
        protected DataTable dt;
        protected DataRow dr;

        private void Page_Load(object sender, System.EventArgs e)
        {
            if(!Page.IsPostBack)
            {
                BindData();

            }
        }

        private void BindData()
        {
            myConnection = new SqlConnection("server=localhost;database=Northwind ;Trusted_Connection=yes;user id=sa;password=;") ;
            adapter=new SqlDataAdapter("select * from Categories",myConnection);
            ds=new DataSet();
            adapter.Fill(ds,"Categories");
            dt=ds.Tables["Categories"];
            this.DataGrid1.DataSource=dt;
            this.DataGrid1.DataBind();

            dt.PrimaryKey=new DataColumn[]{dt.Columns["CategoryID"]};

            ViewState["dt"]=dt;
            ViewState["pk"]=dt.PrimaryKey;
        }

        override protected void OnInit(EventArgs e)
        {
            InitializeComponent();
            base.OnInit(e);
        }

        private void InitializeComponent()
        {
            this.DataGrid1.DeleteCommand += new System.Web.UI.WebControls.DataGridCommandEventHand ler(this.DataGrid1_Delete);
            this.DataGrid1.SelectedIndexChanged += new System.EventHandler(this.DataGrid1_SelectedIndexCh anged);
            this.Load += new System.EventHandler(this.Page_Load);

        }

    public void DataGrid1_SelectedIndexChanged(object sender, System.EventArgs e)
        {

        }
        public void DataGrid1_Delete(object sender,DataGridCommandEventArgs e)
        {
            try
            {
            DataTable dt=(DataTable)ViewState["dt"];
                Response.Write(dt.Rows.Count-1);

            int key=(int)this.DataGrid1.DataKeys[(int)e.Item.ItemIndex];
                Response.Write("Click "+key.ToString()+" Column");

                    dr=dt.Rows.Find(key);
                    if(dr.Equals(""))
                        Response.Write("null");
                    else
                        Response.Write("no null");
                dt.Rows.Remove(dr);


                //dr.Delete();
                //dr.AcceptChanges();
                //BindData();
                DataGrid1.DataBind();
            }
        catch(System.NullReferenceException pp){Response.Write(pp.Message);}
            catch(System.ArgumentException ae){Response.Write(ae.Message);}
        }
    }
}
------------------------------------------
I found the reason that when I delete a row from datagrid,and it will appear again i delete another row again,it may be save the DataTable and the PrimaryKey Columns to the ViewState.But the primaryKey must be serializable ,I don't know how to do it !
----------------------------------------------
By the way,I watch the football match too,because I don't hope China will face the Korea-Republic ,so I hope Iran will be the winner :)

yoooooooooohoooooooooo
I'm happy,
Iran 4-3 Korea
in the next stage
Iran-China(host)
my prediction is Iran 2-1 China :))
what is your prediction?tell me!
Iran alway defeats China :))
(I will think off you problem and will answer you)
Regards to China Football Team .


--------------------------------------------
Mehdi.

I think your problem is due to your DataGrid1_Delete method
change it like below
-----
//...
//dr.Delete();
//dr.AcceptChanges();
//BindData();
ViewState["dt"]=dt;//***This line was added***
DataGrid1.DataSource=dt;//***This line was added***
DataGrid1.DataBind();
-----
I think now it should work correctly.



--------------------------------------------
Mehdi.

HOHO,congratulation!So I am happy too,becase my problem had been solved!I use a ViewState save the sate of the datatable and then all be ok!
By the way,let's wait for the football match,and i welcome the Iran come to China!

u simply will use Thats it!

Always:),
Hovik Melkomian.

Hi Hovik("hamoon SALAMe khodemoon")
he didn't want to delete the row from datasource,he just wanted to delete it from DataSet,Therefore Rows[N].Remove() is better.
Please,refer previous messages.


--------------------------------------------
Mehdi.

Oops so I dindt get it clear. Tnx for ur mess & sorry for wrong post.

Always:),
Hovik Melkomian.