C# 第一次单击时gridView控件中的编辑链接不起作用

我在网格视图中提供了编辑选项。当我单击“编辑链接”时，第一次不会触发，但第二次可以正常工作。请帮我解决这个问题。我已经放置了标记、行编辑和页面加载事件代码

标记代码：

<asp:GridView ID="grdvwid" Width="100%" OnPageIndexChanging="page_changing" AllowPaging="true" AutoGenerateColumns="false" runat="server" Height="119px" onrowcancelingedit="grdvwid_RowCancelingEdit" onrowediting="grdvwid_RowEditing" onrowupdating="grdvwid_RowUpdating"
DataKeyNames="EXTERNAL_ID" onrowdatabound="grdvwid_RowDataBound">

    <SelectedRowStyle CssClass="gS" />
    <AlternatingRowStyle CssClass="gridAlternatingItemStyle1" />
    <RowStyle CssClass="gridItemStyle" />
    <HeaderStyle CssClass="gridheaderstyle" HorizontalAlign="Center"></HeaderStyle>
    <FooterStyle CssClass="gridheaderstyle"></FooterStyle>

    <Columns>
        <asp:CommandField ShowEditButton="true" HeaderText="Edit" ShowDeleteButton="false" CausesValidation="false" />
        <asp:BoundField HeaderText="id" ItemStyle-HorizontalAlign="Center" DataField="ID" SortExpression="ID" Visible="false" />
        <asp:BoundField HeaderText="Date Of Regi" ItemStyle-HorizontalAlign="Center" DataField="REGDATE" SortExpression="doc" ReadOnly="true" />
        <asp:BoundField HeaderText="Time" ItemStyle-HorizontalAlign="Center" DataField="COLTIME" SortExpression="coll_time">
            <ItemStyle Width="50" />
        </asp:BoundField>
        <asp:BoundField HeaderText="Pre_Registerd Time" ItemStyle-HorizontalAlign="Center" DataField="PRETIME" SortExpression="regtime" ReadOnly="true" />
    </Columns>

</asp:GridView>

页面加载事件的代码

private void Page_Load(object sender, System.EventArgs e) {
    try 
    {
        if (Session["UserName"] != null || Session["UserName"] != "") 
        {
            if (!IsPostBack) 
            {
                bindgrid();
                // query.  
            }
        }
        else 
        {
            Page.RegisterStartupScript("sessionmsg", "<script language=javascript>alert('Session Expired,Please Login to continue'); location.href('index.aspx');</script>");
        }
    } 
    catch (Exception ex) 
    {
        Page.RegisterStartupScript("sessionmsg", "<script language=javascript>alert('Session Expired,Please Login to continue'); location.href('index.aspx');</script>");
    }
}

private void页面加载（对象发送方，System.EventArgs e）{
尝试
{
如果（会话[“用户名”]！=null | |会话[“用户名”]！=“”）
{
如果（！IsPostBack）
{
bindgrid（）；
//询问。
}
}
其他的
{
RegisterStartupScript（“sessionmsg”，“警报（'Session Expired，请登录以继续”）；location.href（'index.aspx'）；”；
}
} 
捕获（例外情况除外）
{
RegisterStartupScript（“sessionmsg”，“警报（'Session Expired，请登录以继续”）；location.href（'index.aspx'）；”；
}
}

private void Page_Load(object sender, System.EventArgs e) {
    try 
    {
        if (Session["UserName"] != null || Session["UserName"] != "") 
        {
            if (!IsPostBack) 
            {
                bindgrid();
                // query.  
            }
        }
        else 
        {
            Page.RegisterStartupScript("sessionmsg", "<script language=javascript>alert('Session Expired,Please Login to continue'); location.href('index.aspx');</script>");
        }
    } 
    catch (Exception ex) 
    {
        Page.RegisterStartupScript("sessionmsg", "<script language=javascript>alert('Session Expired,Please Login to continue'); location.href('index.aspx');</script>");
    }
}