Linkbutton inside a gridview not firing

<asp:GridView ID="gvBlockUnblock" runat="server" AutoGenerateColumns="False" 
                       BackColor ="AliceBlue"
                      onrowdatabound="gvBlockUnblock_RowDataBound" DataKeyNames="CPID,PUBLISHED"
                    style="margin-top: 0px" 
                    AllowPaging="True" onpageindexchanging="gvBlockUnblock_PageIndexChanging" 
                    PageSize="10" EnableViewState= "true"
                    onselectedindexchanged="gvBlockUnblock_SelectedInde开发者_StackOverflowxChanged" >

        <Columns>

                    <asp:TemplateField HeaderText="S.No.">
                    <ItemTemplate>
                    <asp:LinkButton ID="lbSNo" runat="server" 
                    Text='<%# (Eval("sno")) %>'
                    PostBackUrl='<%#"~/_UILayer/ComplaintReport.aspx?PINo="+Eval("CPID") %>' >
                    </asp:LinkButton>
                    </ItemTemplate>
                    </asp:TemplateField>

         <asp:BoundField  HeaderText = "Complaint" />

         <asp:HyperLinkField   DataNavigateUrlFields="CPID" datatextfield = "CPID"
                DataNavigateUrlFormatString="WebForm1.aspx?CPID={0}" HeaderText=" Problem Item No"/>


            <asp:BoundField  DataField="NewComplaints" 
                HeaderText="Number of New Complaints" SortExpression="NewComplaints" />
            <asp:BoundField DataField="TotalNumberofComplaints" 
                HeaderText="Total Number of Complaints" SortExpression="TotalNumberofComplaints" />
            <asp:BoundField DataField="NumberofUnblocks" HeaderText="Number of Unblocks" 
                SortExpression="TotalNumberofComplaints" />



          <asp:TemplateField  HeaderText = "Comments">
           <ItemTemplate>
                        <asp:TextBox ID="txtAdminComment" Font-Names="Arial" ReadOnly="false" Width="200" Height="30"
                            TextMode="multiLine" runat="server" BorderStyle="NotSet"></asp:TextBox>
                    </ItemTemplate>
                </asp:TemplateField>


           <asp:TemplateField  HeaderText = " Block / Unblock">
                <ItemTemplate>
                     <asp:button ID ="btnBlockUnblock"  runat = "server" 
                         Text = '<%# CheckBlock(Eval("PUBLISHED")) %>' CommandName="Select" 
                        CommandArgument="<%# ((GridViewRow) Container).RowIndex %>"  CausesValidation="False"  />
                </ItemTemplate>
            </asp:TemplateField>



                    <asp:HyperLinkField   DataNavigateUrlFields="CPID"  Text="View Details"  
                DataNavigateUrlFormatString="ItemHistoryForm.aspx?CPID={0}" HeaderText=" Problem Item No"/>

        </Columns>
    </asp:GridView>

aspx.cs

   protected void gvBlockUnblock_SelectedIndexChanged(object sender, EventArgs e)
    {
        string ComplaintProfileId = gvBlockUnblock.DataKeys[gvBlockUnblock.SelectedIndex].Values["CPID"].ToString();
        string ISPUBLISHED = gvBlockUnblock.DataKeys[gvBlockUnblock.SelectedIndex].Values["PUBLISHED"].ToString();

        string date = System.DateTime.Now.ToString();
        TextBox tb = (TextBox)gvBlockUnblock.Rows[gvBlockUnblock.SelectedIndex].FindControl("txtAdminComment");
        string Comment = tb.Text;
        if (string.IsNullOrEmpty(Comment))
        {

            WebMsgBox.Show("empty");
        }
        else
        {
            if (ISPUBLISHED == "N")
            {
                ISPUBLISHED = "N";
            }
            else
            {
                ISPUBLISHED = "Y";
            }
            string AdminComment = (System.DateTime.Now.ToString() + " :  " + Comment);

            AddCommentBLL.InsertComment(AdminComment, ComplaintProfileId, ISPUBLISHED);
            gvBlockUnblock.DataSource = AddCommentBLL.GetItem();
            gvBlockUnblock.DataBind();
        }
    }

So, on click of the button ID ="btnBlockUnblock", this grid view selectedindex changed needs to fire. The page is refreshing though.

Thanks Sun

You have to use the GridView RowCommand event instead of the GridView SelectedIndex Change.. e.g

protected void gvBlockUnblock_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "Select")
    {

string ComplaintProfileId = gvBlockUnblock.DataKeys[gvBlockUnblock.SelectedIndex].Values["CPID"].ToString();
    string ISPUBLISHED = gvBlockUnblock.DataKeys[gvBlockUnblock.SelectedIndex].Values["PUBLISHED"].ToString();

    string date = System.DateTime.Now.ToString();
    TextBox tb = (TextBox)gvBlockUnblock.Rows[gvBlockUnblock.SelectedIndex].FindControl("txtAdminComment");
    string Comment = tb.Text;
    if (string.IsNullOrEmpty(Comment))
    {

        WebMsgBox.Show("empty");
    }
    else
    {
        if (ISPUBLISHED == "N")
        {
            ISPUBLISHED = "N";
        }
        else
        {
            ISPUBLISHED = "Y";
        }
        string AdminComment = (System.DateTime.Now.ToString() + " :  " + Comment);

        AddCommentBLL.InsertComment(AdminComment, ComplaintProfileId, ISPUBLISHED);
        gvBlockUnblock.DataSource = AddCommentBLL.GetItem();
        gvBlockUnblock.DataBind();
    }
    }
}

Edit: After reading code from your comment, I found your problem.

What happens actually, when you click the button, the Page Load event fires before your gridview event and there your gridview data again binded and it lost your fired event. You have to examine your page Postback by putting if(!IsPostBack) in your page load where you are trying to bind your data to gridview.

    protected void Page_Load(object sender, EventArgs e)
    {
     if(!IsPostBack)
     {
        // gets the items table using stored proc GetItem
        gvBlockUnblock.DataSource = AddCommentBLL.GetItem();
        gvBlockUnblock.DataBind();
        // used for paging
        Session["MyDataSett"] = gvBlockUnblock.DataSource;
     }
   }