void btnDeleteSelect_Click(object sender, EventArgs e)
        {
            IList <long> sendedMessageList = new List <long>();

            foreach (GridViewRow row in this.messagesList.Rows)
            {
                CheckBox box = (CheckBox)row.FindControl("checkboxCol");
                if ((box != null) && box.Checked)
                {
                    Label label = (Label)row.FindControl("lblMessage");
                    if (label != null)
                    {
                        sendedMessageList.Add(Convert.ToInt64(label.Text));
                    }
                }
            }
            if (sendedMessageList.Count > 0)
            {
                CommentsHelper.DeleteSendedMessages(sendedMessageList);
                this.BindData();
            }
            else
            {
                this.ShowMessage("请选中要删除的信息", false);
            }
        }