在Jquery UI Multiselect小部件中回发后，所选项目仍保持选中状态

Question

I am trying to create an GridView in asp.net which can filter each column of gridview as Excel can. For this I had created an Gridview and used Jquery multiselect widget on the header of each column of GridView to do the filter.

<cc1:GridView ID="gvDailyTracker" runat="server" CssClass="mGrid" CellSpacing="2" AutoGenerateColumns="false"
              ShowFooter="false" AllowPaging="true" OnPageIndexChanging="gvDailyTracker_PageIndexChanging" OnRowDataBound="gvDailyTracker_RowDataBound"
              OnRowCommand="gvDailyTracker_RowCommand" OnRowEditing="gvDailyTracker_RowEditing" OnSelectedIndexChanged="gvDailyTracker_SelectedIndexChanged"
              OnDataBound="gvDailyTracker_DataBound">
    <EmptyDataRowStyle BackColor="LightBlue" Width="1180" />
    <EmptyDataTemplate>
        No Data Found From The Current Selection,Please Select  Appropriate Search Criteria.  
    </EmptyDataTemplate>
    <Columns>
        <asp:TemplateField SortExpression="DateProcessed" HeaderStyle-Font-Bold="true"
            HeaderStyle-Font-Names="Calibre" HeaderStyle-ForeColor="White">
            <HeaderTemplate>
                <select id="ddlDateProcessed" name="test" runat="server" multiple="true" style="width: 100px;">
                </select>
            </HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblDateProcessed" runat="server" Text='<%#Eval("DateProcessed") %>' CssClass="GridContent" />
            </ItemTemplate>
        </asp:TemplateField>

        <asp:TemplateField SortExpression="InvoiceFileName" HeaderStyle-Font-Bold="true"
            HeaderStyle-Font-Names="Calibre" HeaderStyle-ForeColor="White">
            <HeaderTemplate>
                <select id="ddlInvoiceFilename" name="test" runat="server" multiple="true" style="width: 100px;">
                </select>
            </HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblInvoiceFileName" runat="server" Text='<%#Eval("InvoiceFileName") %>' CssClass="GridContent" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</cc1:GridView>
<script type="text/javascript">        
    $(document).ready(function () {
        $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect({
            SelectedText: 'DateProcessed',
            noneSelectedText: 'DateProcessed',
            close: function () {
                var dateProcessed = $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                document.getElementById('<%=txtddlDateProcessed.ClientID%>').value = dateProcessed;
                document.getElementById('<%=btnPostBack.ClientID %>').click();
            },
            beforeopen: function () {
                $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect("checkAll");
            },
            minWidth: 120
        });


        $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect({
            SelectedText: 'InvoiceFileName',
            noneSelectedText: 'InvoiceFileName',
            close: function () {
                var InvoiceFilename = $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                document.getElementById('<%=txtddlInvoiceFileName.ClientID%>').value = InvoiceFilename;
                document.getElementById('<%=btnPostBack.ClientID %>').click();
            },
            beforeopen: function () {
                $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect("checkAll");
            },
            minWidth: 120
        });
    });
    function test() {
                BindAllMultiSelectData();
                var dateProcessed = $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                var InvoiceFilename = $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                document.getElementById('<%=txtddlDateProcessed.ClientID%>').value = dateProcessed;
                document.getElementById('<%=txtddlInvoiceFileName.ClientID%>').value = InvoiceFilename;
                }
    function BindAllMultiSelectData() {
        $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect({
            SelectedText: 'DateProcessed',
            noneSelectedText: 'DateProcessed',
            close: function () {
                var dateProcessed = $("#MainContent_gvDailyTracker_ddlDateProcessed").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                document.getElementById('<%=txtddlDateProcessed.ClientID%>').value = dateProcessed;
                document.getElementById('<%=btnPostBack.ClientID %>').click();
            },
           minWidth: 120
       });


        $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect({
            SelectedText: 'InvoiceFileName',
            noneSelectedText: 'InvoiceFileName',
            close: function () {
                var InvoiceFilename = $("#MainContent_gvDailyTracker_ddlInvoiceFilename").multiselect("getChecked").map(function () {
                    return this.value;
                }).get();
                document.getElementById('<%=txtddlInvoiceFileName.ClientID%>').value = InvoiceFilename;
                document.getElementById('<%=btnPostBack.ClientID %>').click();
            },
            minWidth: 120
        });
</script>

C# Code for Filtering the gridView

protected void btnPostBack_Click(object sender, EventArgs e)
{
    if (!txtddlDateProcessed.Text.Equals(null) && txtddlDateProcessed.Text != string.Empty)
    {
    string filter=txtddlDateProcessed.Text;
    filter = filter.Replace(",", "','");
    string strFilter="[DateProcessed]" + " in ('" + filter + "')";
    FilterHeader(strFilter);
    }

    if (!txtddlInvoiceFileName.Text.Equals(null) && txtddlInvoiceFileName.Text != string.Empty)
    {
    string filter=txtddlInvoiceFileName.Text;
    filter = filter.Replace(",", "','");
    string strFilter="[InvoiceFileName]" + " in ('" + filter + "')";
    FilterHeader(strFilter);
    }
     ScriptManager.RegisterStartupScript(this, this.GetType(), Guid.NewGuid().ToString(), "test();", true);
}

Up to here every thing is working fine and I am able to filter the grid view. Now what i actually want is that after filtration of grid view, The Selection made on Multi Select widgets remains still. Currently after filtration all multiselect get unchecked.

Note:-1. I am binding Multiselect dynamically .(Distinct records of that column values binding to the multiselect)

private void BindHeaderDropDown(string columnName, DataTable dt, string controlName)
{
    System.Web.UI.HtmlControls.HtmlSelect objControlName = (System.Web.UI.HtmlControls.HtmlSelect)gvDailyTracker.HeaderRow.FindControl(controlName);
    DataView view=new DataView(dt);
    DataTable distinctValues = view.ToTable(true, columnName);
    objControlName.DataSource = distinctValues;
    objControlName.DataTextField = columnName;
    objControlName.DataValueField = columnName;
    objControlName.DataBind();
}

On Page load after binding the grid, I am binding the Multiselect widgets by calling BindHeaderDropDown Function And after filtering the grid view with the selected values, again i am calling the same function ie BindHeaderDropDown for binding Multiselect.In case if I am not calling this function after filteration,nothing get binded to the Multiselect and it is blank without a single checkbox items.

Please help me and guide me, what i will do ? Thanks In Advance.

Answer 1

As you are rebinding your Multiselect controls, in each post back (page load method), that is why the user selected values are lost, because you are re-generating your filter controls.

To persist the user selection, you can update your Re-binding method and add Logic to check if it is Initial load or a post back. If it is a post-back then after rebinding your controls, add/set the values manually in the respective filter controls.

Hopefully it may solve your issue. Thanks

private void BindHeaderDropDown(string columnName, DataTable dt, string controlName)
{
  System.Web.UI.HtmlControls.HtmlSelect objControlName = (System.Web.UI.HtmlControls.HtmlSelect)gvDailyTracker.HeaderRow.FindControl(controlName);
  DataView view=new DataView(dt);
  DataTable distinctValues = view.ToTable(true, columnName);
  objControlName.DataSource = distinctValues;
  objControlName.DataTextField = columnName;
  objControlName.DataValueField = columnName;
  objControlName.DataBind();
  // check if it is post-back
  objControlName.Text = Latest User value;
}

Answer 2

Better u can save your multiselected value in hidden field.And again according to hidden field value u can populate those items in multiselect dropdown.

This method for storing the value in the hidden field

close: function (event, ui) {

                var values = new Array();
                $("#ddlAssignedTo").multiselect("getChecked").each(function (index, item) {
                    values.push($(item).val());
                });
                $("input[id*=hdnAssignTo]").val(values.join(","));
            }

this the method for populating the value in multislect dropdown according to hiddenfield

  function loadSelectedUsers() {
        $("#ddlAssignedTo").multiselect("uncheckAll");

        var listAssigned = $("#ctl00_MainContent_ddlAssignedTo option:selected").length;

        if (listAssigned == 0) {

            if ($("#<%=hdnAssignTo.ClientID%>").val() != null && $("#<%=hdnAssignTo.ClientID%>").val() != undefined && $("#<%=hdnAssignTo.ClientID%>").val() != "") {
                var arrUserIdSelected = $("#<%=hdnAssignTo.ClientID%>").val().split(',');


                if (arrUserIdSelected != null && arrUserIdSelected.length > 0) {
                    for (var iCount = 0; iCount < arrUserIdSelected.length; iCount++) {
                        $("#ddlAssignedTo").multiselect("widget").find("input:checkbox[value='" + arrUserIdSelected[iCount] + "']").attr("checked", "checked");
                        $("#ddlAssignedTo option[value='" + arrUserIdSelected[iCount] + "']").attr("selected", 1);
                        $("#ddlAssignedTo").multiselect("refresh");
                    }
                }
            }
        } 
    }