我是一名Asp.Net的初学者，最近，在学习DataGrid绑定数据的时候，总觉得哪里好像不对。但是，又查不出错误！比如下面在阶段考试时，我打得一段DataGrid绑定数据的代码.
请各位老鸟们帮我看一下：
default.aspx中：


    <Columns>
                                <asp:TemplateColumn>
                                        <ItemTemplate>
                                                <asp:Label   ID="lblstuno"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuNo")   %> '> </asp:Label>
                                        </ItemTemplate>
                                        <EditItemTemplate>
                                                <asp:TextBox   ID="txtstuno"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuNo")   %> '> </asp:TextBox>
                                        </EditItemTemplate>
                                </asp:TemplateColumn>
                                <asp:TemplateColumn>
                                        <ItemTemplate>
                                                <asp:Label   ID="stuname1"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuName")   %> '> </asp:Label>
                                        </ItemTemplate>
                                        <EditItemTemplate>
                                                <asp:TextBox   ID="txtstuname"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuName")   %> '> </asp:TextBox>
                                        </EditItemTemplate>
                                </asp:TemplateColumn>
                                <asp:TemplateColumn>
                                        <ItemTemplate>
                                                <asp:Label   ID="stuaddr1"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuAddress")   %> '> </asp:Label>
                                        </ItemTemplate>
                                        <EditItemTemplate>
                                                <asp:TextBox   ID="txtstuaddr"   runat="server"   Text=' <%#   DataBinder.Eval(Container,   "DataItem.stuAddress")   %> '> </asp:TextBox>
                                        </EditItemTemplate>
                                        <FooterTemplate>
                                                <asp:Button   ID="Button1"   runat="server"   CommandName="btnaddnew"   Text="AddNew"   />
                                        </FooterTemplate>
                                </asp:TemplateColumn>
                                <asp:ButtonColumn   CommandName="Select"   Text="选择"> </asp:ButtonColumn>
                                <asp:EditCommandColumn   CancelText="取消"   EditText="编辑"   UpdateText="更新"> </asp:EditCommandColumn>
                                <asp:ButtonColumn   CommandName="Delete"   Text="删除"> </asp:ButtonColumn>
                        </Columns>


Default.aspx.cs   中:


public   partial   class   _Default   :   System.Web.UI.Page  
{
        private   string   insertCommad   =   "Insert   into   stuInfo(stuNo,stuName,stuAddress)   Values(@stuno,@stuname,@stuaddr)";
        private   string   updateCommad   =   "update   stuInfo   set   stuName=@stuname,stuAddress=@stuaddr   where   stuNo=@stuno";
        private   string   deleteCommad   =   "delete   from   stuInfo   where   stuNo=@stuno";
        private   bool   isAddNew   =   true;

        protected   void   Page_Load(object   sender,   EventArgs   e)
        {
                if(!Page.IsPostBack)
                {
                        BindData();
                }
        }
        private   void   BindData()
        {
                BindData(false);
        }
        private   void   BindData(bool   isAddNew)
        {
                SqlConnection   cnn   =   new   SqlConnection("server=.;uid=sa;pwd=;database=stuDB");
                SqlDataAdapter   adpt   =   new   SqlDataAdapter("select   *   from   stuInfo",cnn);
                DataTable   dt   =   new   DataTable();
                adpt.Fill(dt);

                if   (isAddNew)
                {
                        DataRow   dr   =   dt.NewRow();
                        dt.Rows.Add(dr);
                }

                DataGrid1.DataSource   =   dt;

                if   (isAddNew)
                        DataGrid1.EditItemIndex   =   dt.Rows.Count   -   1;

                DataBind();
        }
        private   SqlCommand   BuidCommand(string   CommandText)
        {
                SqlConnection   cnn   =   new   SqlConnection("server=.;uid=sa;pwd=;database=stuDB");
                SqlCommand   command   =   new   SqlCommand(CommandText,   cnn);
                command.CommandType   =   CommandType.Text;
                cnn.Open();
                return   command;
        }
        private   void   Execute(string   CommandText,DataGridCommandEventArgs   e)
        {
                string   stuno   =   ((TextBox)e.Item.FindControl("txtstuno")).Text;
                string   stuname   =   ((TextBox)e.Item.FindControl("txtstuname")).Text;
                string   stuaddr   =   Convert.ToString(((TextBox)e.Item.FindControl("txtstuaddr")).Text);

                SqlParameter   Sstuno   =   new   SqlParameter("@stuno",   SqlDbType.VarChar);
                SqlParameter   Sstuname   =   new   SqlParameter("@stuname",   SqlDbType.VarChar);
                SqlParameter   Sstuaddr   =   new   SqlParameter("@stuaddr",   SqlDbType.NVarChar);

                Sstuno.Value   =   stuno;
                Sstuname.Value   =   stuname;
                Sstuaddr.Value   =   stuaddr;

                if   (stuno   ==   ""   &&   isAddNew   ==   false)
                {
                        isAddNew   =   true;
                        Execute(insertCommad,e);
                        return;
                }

                SqlCommand   cmd   =   BuidCommand(CommandText);
                if   (!isAddNew)
                {
                        cmd.Parameters.Add(Sstuno);
                }
                cmd.Parameters.Add(Sstuname);
                cmd.Parameters.Add(Sstuaddr);
                cmd.ExecuteNonQuery();
                DataGrid1.EditItemIndex   =   -1;
        }
        protected   void   DataGrid1_ItemCommand(object   source,   DataGridCommandEventArgs   e)
        {
                switch(e.CommandName.ToLower())
                {
                        case   "edit":
                                DataGrid1.EditItemIndex   =   e.Item.ItemIndex;
                                BindData();
                                break;
                        case   "delete":
                                string   stuno   =   ((Label)e.Item.FindControl("lblstuno")).Text;
                                SqlParameter   Sstuno   =   new   SqlParameter("@stuno",   SqlDbType.VarChar);
                                Sstuno.Value   =   stuno;
                                SqlCommand   cmd   =   BuidCommand(deleteCommad);
                                cmd.Parameters.Add(Sstuno);
                                cmd.ExecuteNonQuery();
                                DataGrid1.EditItemIndex   =   -1;
                                BindData();
                                break;
                        case   "update":
                                Execute(updateCommad,e);
                                break;
                        case   "cancel":
                                DataGrid1.EditItemIndex   =   -1;
                                BindData();
                                break;
                        case   "insert":
                                BindData(true);
                                break;
                }
        }
}
[em4][em4][em4][em4][em4]