search datatable using viewstate without go to database every postback and search using dataview filter option example using c#

first time you should fill viewstate with your database table.

 private void LoadData()

    {

        try

        {

            DataTable TblSections = new DataTable();

            if (ViewState["Pusers"] == null)

            {

                if (this.currentRequest.REQUEST_ID != null)

                {

                    TblSections = workflowGetData.WORK_FLOWS_PERMISSION_MANAGERIAL_GET_STAGE_USERS(this.currentRequest.WORK_FLOW_ID.ToString(), this.currentRequest.WORK_FLOW_TYPE.ToString(), this.currentRequest.CURRENT_STAGE_IDs[0].ToString(), "");

                    ViewState["Pusers"] = TblSections;

                    //else

                    //    TblSections = workflowGetData.WORK_FLOWS_PERMISSION_MANAGERIAL_GET_STAGE_USERS_BY_REQUEST_ID(hid_workflow_id.Value, hid_workflow_type.Value, hid_stage_id.Value, "", hid_request_id.Value);

                }

            }

            else

                TblSections = (DataTable)ViewState["Pusers"];

            DataView DV = new DataView();

            DV = TblSections.DefaultView;

            if (TXT_USER_ID.Text.Length > 0)

                DV.RowFilter = "USER_ID=" + TXT_USER_ID.Text;

            if (TXT_USER_FULL_NAME.Text.Length > 0)

                DV.RowFilter = String.Format("emp_name LIKE '*{0}*'", EscapeLikeValue(TXT_USER_FULL_NAME.Text));

            GV_USERS.DataSource = TblSections;

            GV_USERS.DataBind();

        }

        catch (Exception ex)

        {

            basepage.FormShowMessage(lblmessage, Enum_Class.MessageStatus.failure, Resources.GlobalErrorMessages.Error_GeneralException);

        }

    }

---------------------------------------------
  public static string EscapeLikeValue(string valueWithoutWildcards)
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < valueWithoutWildcards.Length; i++)
        {
            char c = valueWithoutWildcards[i];
            if (c == '*' || c == '%' || c == '[' || c == ']')
                sb.Append("[").Append(c).Append("]");
            else if (c == '\'')
                sb.Append("''");
            else
                sb.Append(c);
        }
        return sb.ToString();
    }