js事件触发事件

 <tr>
                    <td colspan="6" class="text_color">
                        <asp:TextBox runat="server" ID="txtQuery" Width="20%"></asp:TextBox>   
                        <asp:DropDownList ID="ddlReportInstance" runat="server"></asp:DropDownList>   
                        <asp:Button runat="server" ID="btnQuery" CssClass="formButton" Text="搜索" OnClick="btnQuery_Click" />   
                                <a href="#" onclick="ShowQuery()">高级查询</a>      
                        页显示条数设置
                           

                        <asp:DropDownList ID="seletPageNum" runat="server"></asp:DropDownList>
                    </td>
                </tr>

                <tr>
                    <td colspan="6">
                        <asp:UpdatePanel runat="server" ID="UpdatePanel2">
                            <ContentTemplate>
                                <SOA:DeluxeGrid ID="dgDataSource" runat="server" DataSourceID="datasource" AllowSorting="true" OnSorting="dgDataSource_Sorting"
                                    PageSize="20" AutoGenerateColumns="False" DataSourceMaxRow="0" AllowPaging="True"  
                                    CssClass="dataList" Width="100%" OnRowDataBound="dgDataSource_RowDataBound">
<%--                                    <Columns>
                                        <asp:TemplateField HeaderText="操作" Visible="false" SortExpression="">
                                            <ItemTemplate>
                                                <div>
                                                    <asp:LinkButton runat="server" ID="btnEdit">编辑</asp:LinkButton>   
                                                    <asp:LinkButton runat="server" ID="btnDel">删除</asp:LinkButton>
                                                </div>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                    </Columns>--%>
                                    <HeaderStyle CssClass="head" />
                                    <PagerStyle CssClass="pager" />
                                    <RowStyle HorizontalAlign="Left" CssClass="item" />
                                    <AlternatingRowStyle HorizontalAlign="Left" CssClass="aitem" />
                                    <EmptyDataTemplate>
                                        暂时没有您需要的数据
                                    </EmptyDataTemplate>
                                    <PagerSettings FirstPageText="<<" LastPageText=">>" Mode="NextPreviousFirstLast"
                                        NextPageText="下一页" Position="Bottom" PreviousPageText="上一页"></PagerSettings>
                                </SOA:DeluxeGrid>
                                <SOA:DeluxeObjectDataSource ID="datasource" runat="server" EnablePaging="True" TypeName="MCS.Library.SOA.DataObjects.DataSources.ProcessQueryDataSource" OnSelecting="dataSource_Selecting">
                                    <SelectParameters>
                                        <asp:Parameter Name="tempID" Type="String" />
                                        <asp:Parameter Direction="InputOutput" Name="totalCount" Type="Int32" />
                                    </SelectParameters>
                                </SOA:DeluxeObjectDataSource>
                                <asp:HiddenField runat="server" ID="hfDSID" />
                            </ContentTemplate>
                            <Triggers>
                                <asp:AsyncPostBackTrigger ControlID="btnQuery" EventName="click" />
                            </Triggers>
                        </asp:UpdatePanel>
                    </td>
                </tr>

<script type="text/javascript">
   $("#seletPageNum").change(function(){
        document.getElementById("btnQuery").click();
    })

</script>

        protected void dataSource_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
        {
            dgDataSource.PageSize = Convert.ToInt32(seletPageNum.SelectedValue);

            if (e.ExecutingSelectCount == false)
            {
                e.InputParameters["tempID"] = Template.Id;
                WhereSqlClauseBuilder where = new WhereSqlClauseBuilder();

                List<KeyAndValue> dataItems = new List<KeyAndValue>();
                if (!hfQueryStr.Value.IsNullOrEmpty())
                    dataItems = JSONSerializerExecute.Deserialize<List<KeyAndValue>>(hfQueryStr.Value);

                foreach (var item in dataItems)
                {
                    var parameter = Template.Config.DataQuery.SearchParameters.Find(p => p.ParameterName == item.Key);

                    if (parameter != null)
                        where.AppendItem(item.Key, TSqlBuilder.Instance.CheckUnicodeQuotationMark(item.Value), "", parameter.FormatString, true);
                }

                if (!txtQuery.Text.IsNullOrEmpty())
                {//【普通搜索】
                    if (Template.Config.DataQuery.DefaultWhereClause.Contains("=") == true)
                        where.AppendItem(Template.Config.DataQuery.DefaultWhereClause.TrimEnd(‘=‘), txtQuery.Text);
                    else
                        where.AppendItem(Template.Config.DataQuery.DefaultWhereClause, "%" + txtQuery.Text + "%", "LIKE");
                }

                if (!string.IsNullOrEmpty(Template.DefaultValue))
                { //没值查询所有时间的数据
                    if (Template.IsDefault)
                    {
                        if (!ddlReportInstance.SelectedValue.IsNullOrEmpty())
                        {//【普通搜索】
                            if (ddlReportInstance.Items.Count > 0)
                                where.AppendItem(ReportTimeName, ddlReportInstance.SelectedItem.Text);
                        }
                    }
                    else
                    {
                        where.AppendItem(ReportTimeName, DataFormTemplateQueryDataAdapter.Instance.GetReportTimeName(Template.DefaultValue));
                    }
                }
                    

                this.datasource.Condition = where;

            }
        }

        protected void btnQuery_Click(object sender, EventArgs e)
        {
            this.dgDataSource.DataBind();

        }