在分頁期間保留復選框 state

Question

我有一個 gridview 包含復選框並啟用了分頁。 現在，當我選中任何一個復選框然后更改頁面時，當時所有選中的復選框都會失去它們的狀態。 我想在分頁期間保留復選框的狀態。 我怎樣才能做到這一點？

//這里是.aspx頁面的代碼

<%@ Page Title="Search candidates based on vacancy" Language="C#" MasterPageFile="~/HR Department/hrmasterpage.master"
AutoEventWireup="true" CodeFile="searcAppForVac.aspx.cs"    Inherits="HR_Department_searcAppForVac" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
<table width="100%">
    <tr>
        <td>
            &nbsp;
        </td>
    </tr>
    <tr>
        <td align="center" class="tdtitle">
            Search Candidates
        </td>
    </tr>
    <tr>
        <td>
            <asp:ScriptManager ID="ScriptManager1" runat="server">
            </asp:ScriptManager>
            <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                <ContentTemplate>
                    <table width="100%">
                        <tr>
                            <td class="RowHeight" width="20%">
                                Select Company
                            </td>
                            <td width="30%">
                                <asp:DropDownList ID="companyList" runat="server" AppendDataBoundItems="true" AutoPostBack="True"
                                    OnSelectedIndexChanged="companyList_SelectedIndexChanged" Width="150px">
                                    <asp:ListItem Text="-Select Company-" Value="-1"></asp:ListItem>
                                </asp:DropDownList>
                            </td>
                            <td width="20%">
                                Select Department
                            </td>
                            <td width="30%">
                                <asp:DropDownList ID="deptList" runat="server" AppendDataBoundItems="true" AutoPostBack="True"
                                    onclick="Validate();" OnSelectedIndexChanged="deptList_SelectedIndexChanged"
                                    Width="150px">
                                    <asp:ListItem Value="-1">-Select Department-</asp:ListItem>
                                </asp:DropDownList>
                            </td>
                        </tr>
                        <tr>
                            <td class="RowHeight" width="20%">
                                Select Vacancy
                            </td>
                            <td colspan="3" width="*">
                                <asp:DropDownList ID="vacanyList" runat="server" AppendDataBoundItems="true" 
                                    Width="200px" AutoPostBack="True" 
                                    onselectedindexchanged="vacanyList_SelectedIndexChanged">
                                    <asp:ListItem Value="-1">-Select Vacancy-</asp:ListItem>
                                </asp:DropDownList>
                            </td>
                        </tr>
                        <tr>
                            <td colspan="4" align="center">
                                &nbsp;
                                <asp:Label ID="notifyLbl" runat="server" Font-Size="Large" ForeColor="Red" 
                                    Text="Label"></asp:Label>
                            </td>
                        </tr>
                        <tr>
                            <td colspan="4">
                                <asp:Label ID="titleLbl" runat="server" Font-Size="Large" ForeColor="Red" 
                                    Text="Label"></asp:Label>
                            </td>
                        </tr>
                        <tr>
                            <td colspan="4">
                                &nbsp;</td>
                        </tr>
                        <tr>
                            <td colspan="4">
                                <asp:GridView ID="appForVacGrid" runat="server" AutoGenerateColumns="False" 
                                CellPadding="4" AllowPaging="True" 
                                    onpageindexchanging="appForVacGrid_PageIndexChanging" GridLines="None" 
                                    PageSize="3" CssClass="mGrid">
                                    <RowStyle BackColor="#EFF3FB" />
                                    <Columns>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                App.ID
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="appIdLbl" runat="server" Text='<%# Eval("AppId") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                First Name
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="firstNameLbl" runat="server" Text='<%# Eval("AppFirstName") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                Last Name
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="lastNameLbl" runat="server" Text='<%# Eval("AppLastName") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                Qualification
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="qualiNameLbl" runat="server" Text='<%# Eval("QualiName") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                &nbsp;Experience
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="Label1" runat="server" Text='<%# Eval("TotalExpYear") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                EmailId
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="emailLbl" runat="server" Text='<%# Eval("AppEmailId1") %>'></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField>
                                            <HeaderTemplate>
                                                Send Mail
                                            </HeaderTemplate>
                                            <ItemTemplate>
                                                <asp:CheckBox ID="sendMailBox" runat="server" />
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                    </Columns>
                                    <FooterStyle Font-Bold="True" ForeColor="White" 
                                        HorizontalAlign="Right" />
                                    <PagerStyle ForeColor="White" HorizontalAlign="Center" 
                                        VerticalAlign="Top" CssClass="pgr" />
                                    <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                                    <HeaderStyle Font-Bold="True" ForeColor="White" 
                                        Font-Size="Medium" HorizontalAlign="Left" />
                                    <AlternatingRowStyle CssClass="alt" />
                                </asp:GridView>
                            </td>
                        </tr>
                        <tr>
                            <td colspan="4" align="center">
                                &nbsp;
                            </td>
                        </tr>
                        <tr>
                            <td align="center" colspan="4">
                                <asp:Button ID="sendMailBtn" runat="server" Height="40px" Text="SEND MAIL" 
                                    Width="100px" onclick="sendMailBtn_Click" />
                            </td>
                        </tr>
                        <tr>
                            <%--<td>
                                &nbsp;
                            </td>--%>
                        </tr>
                    </table>
                </ContentTemplate>
                <Triggers>
                <asp:AsyncPostBackTrigger ControlID="companyList" EventName="SelectedIndexChanged" />
                <asp:AsyncPostBackTrigger ControlID="deptList" EventName="SelectedIndexChanged" />
                <asp:AsyncPostBackTrigger ControlID="appForVacGrid" EventName="pageindexchanged" />
                </Triggers>
              </asp:UpdatePanel>


        </td>
    </tr>
    <tr>
        <td>
            &nbsp;
        </td>
    </tr>
    <tr>
        <td>
            &nbsp;
        </td>
    </tr>
</table>

<script type="text/javascript">

    function alertOnBadSelection() {
        var select = document.getElementById('companyList');
        if (select.options[select.selectedIndex].value == "-Select Company-") {
            alert('Please Select Company!');
            return false;
        }
    }

</script>

//.aspx.cs頁面的代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Collections;

public partial class HR_Department_searcAppForVac : System.Web.UI.Page
{
DataOperation oDo = new DataOperation();
AppVacancyDetailClass objAppVacDetail = new AppVacancyDetailClass();
protected void Page_Load(object sender, EventArgs e)
{
    notifyLbl.Visible = false;
    titleLbl.Visible = false;
    sendMailBtn.Visible = false;
    //mailSentLbl.Visible = false;
    try
    {
        if (!IsPostBack)
        {
            //Disable department dropdown list and vacancy dropdown list till company is not selected.
            deptList.Enabled = false;
            vacanyList.Enabled = false;
            //Fill Company dropdown list.
            DataTable objCmpnyTable = oDo.DropDownList("select * from tblCompanyMaster");
            if (objCmpnyTable.Rows.Count > 0)
            {
                companyList.DataSource = objCmpnyTable;
                companyList.DataValueField = "CompId";
                companyList.DataTextField = "CompName";
                companyList.DataBind();
            }
            else
            {
                notifyLbl.Visible = true;
                notifyLbl.Text = "There is not any company in the list.";
            }
        }
        else
        {
            if (companyList.SelectedIndex <= 0)
            {
                //Disable department dropdown list and vacancy dropdown list till company is not selected.
                deptList.Enabled = false;
                vacanyList.Enabled = false;
            }
        }
     }
     catch (Exception)
     {
          throw;
     }
 }
protected void companyList_SelectedIndexChanged(object sender, EventArgs e)
{
    //Disable vacancy dropdown list till depratment list is not selected
    vacanyList.Enabled = false;
    appForVacGrid.DataSource = null;
    appForVacGrid.DataBind();
    try
    {
        if (companyList.SelectedIndex > 0)
        {
            deptList.Enabled = true;
            deptList.Items.Clear();
            string str = "select * from vwCompWiseList where CompId=" + companyList.SelectedValue;
            DataTable objDeptTable = oDo.DropDownList("select DeptId,DeptName from vwCompWiseDept where CompId= "+companyList.SelectedValue);
            if (objDeptTable.Rows.Count > 0)
            {
                deptList.DataSource = objDeptTable;
                deptList.DataTextField = "DeptName";
                deptList.DataValueField = "deptId";
                deptList.DataBind();
                deptList.Items.Insert(0, new ListItem("--Select Department--", "-1"));
            }
            else 
            {
                deptList.Items.Insert(0, new ListItem("--No Departments--", "-1"));
                notifyLbl.Visible = true;
                notifyLbl.Text = "No Departments Available in " + companyList.SelectedItem.Text;
            }
        }
        else
        {
            notifyLbl.Visible = true;
            notifyLbl.Text = "Select Company....";
            appForVacGrid.DataSource = null;
            appForVacGrid.DataBind();
        }
    }
    catch (Exception)
    {

        throw;
    }    
}
protected void deptList_SelectedIndexChanged(object sender, EventArgs e)
{
    try
    {
        if (deptList.SelectedIndex > 0)
        {
            vacanyList.Enabled = true;
            vacanyList.Items.Clear();
            DataTable objVacancytbl = oDo.DropDownList("select VacId,VacTitle from tblVacancyMaster where DeptId =" + deptList.SelectedValue + " and CompId=" + companyList.SelectedValue);
            if (objVacancytbl.Rows.Count > 0)
            {
                vacanyList.DataSource = objVacancytbl;
                vacanyList.DataValueField = "VacId";
                vacanyList.DataTextField = "VacTitle";
                vacanyList.DataBind();
                vacanyList.Items.Insert(0, new ListItem("--Select Vacancy--", "-1"));
                appForVacGrid.DataSource = null;
                appForVacGrid.DataBind();
            }
            else
            {
                notifyLbl.Visible = true;
                notifyLbl.Text = "ALL VACANCIES ARE CLOSED IN "+" "+deptList.SelectedItem.Text.ToUpper();
                vacanyList.Enabled = false;
                appForVacGrid.DataSource = null;
                appForVacGrid.DataBind();
            }
        }
        else
        {
            notifyLbl.Visible = true;
            notifyLbl.Text = "Select Department...";
            appForVacGrid.DataSource = null;
            appForVacGrid.DataBind();
            vacanyList.Enabled = false;
        }
    }
    catch (Exception)
    {

        throw;
    }
}
protected void vacanyList_SelectedIndexChanged(object sender, EventArgs e)
{
    try
    {
        DataTable AppListTbl = objAppVacDetail.GetValue("CompId=" + companyList.SelectedValue + " and DeptId=" + deptList.SelectedValue + " and VacId=" + vacanyList.SelectedValue);
        if (AppListTbl.Rows.Count > 0)
        {
            appForVacGrid.DataSource = AppListTbl;
            appForVacGrid.DataBind();
            appForVacGrid.Columns[5].Visible = false;
            Session.Add("snAppListTbl", AppListTbl);
            titleLbl.Visible = true;
            titleLbl.Text = AppListTbl.Rows.Count.ToString() + " " + "CANDIDATE(S) ARE ELIGIBLE FOR THE POST OF" + " " + vacanyList.SelectedItem.Text.ToUpper() + ".";
            sendMailBtn.Visible = true;
        }
        else
        {
            notifyLbl.Visible = true;
            notifyLbl.Text = "ALL VACANCIES ARE CLOSED IN " + " " + deptList.SelectedItem.Text.ToUpper();
            appForVacGrid.DataSource = null;
            appForVacGrid.DataBind();
        }
    }
    catch (Exception)
    {

        throw;
    }
}
protected void appForVacGrid_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
        //DataTable AppListTbl = (DataTable)Session["snAppListTbl"];
        titleLbl.Visible = true;
        titleLbl.Text = ((DataTable)Session["snAppListTbl"]).Rows.Count.ToString() + " " + "CANDIDATE(S) ARE ELIGIBLE FOR THE POST OF" + " " + vacanyList.SelectedItem.Text.ToUpper() + ".";
        appForVacGrid.PageIndex = e.NewPageIndex;
        appForVacGrid.DataSource = (DataTable)Session["snAppListTbl"];
        appForVacGrid.DataBind();
        sendMailBtn.Visible = true;
}
protected void sendMailBtn_Click(object sender, EventArgs e)
{
    DataTable AppListTable = ((DataTable)Session["snAppListTbl"]);
    int intTotalRows = AppListTable.Rows.Count;
    string strFromId="chetan.patel@sahmed.com",strToId="",strCcId="",strBccId="";
    string strVacTitle="",strCompName="",strMailBody="";
    string strSubject = "Rgarding Selection of Your Resume";
    Label EmailLbl;
    bool isMailSent=false;
    //for (int intRow = 0; intRow < intTotalRows; intRow++)
    foreach (GridViewRow Row in appForVacGrid.Rows)
    {
        CheckBox objSendMail = (CheckBox)Row.FindControl("sendMailBox");
        //CheckBox objSendMail = (CheckBox)appForVacGrid.Rows[Row].FindControl("sendMailBox");
        if (objSendMail.Checked)
        {
            if (strToId == "")
            {
                //strToId = AppListTable.Rows[Row]["AppEmailId1"].ToString();
                EmailLbl = (Label)Row.FindControl("emailLbl");
                strToId = EmailLbl.Text;
            }
            else
            {
                //strToId += "," + AppListTable.Rows[Row]["AppEmailId1"].ToString();
                EmailLbl = (Label)Row.FindControl("emailLbl");
                strToId +=","+ EmailLbl.Text;
            }
        }
    }
    strVacTitle = vacanyList.SelectedItem.Text;
    strCompName = companyList.SelectedItem.Text;
    ////appForVacGrid.AllowPaging = false;
    ////appForVacGrid.DataBind();
     strMailBody = CommonProcedures.GetMailBody(strVacTitle, strCompName);
    isMailSent=CommonProcedures.SendMail(strFromId, strToId, strCcId, strBccId, strSubject, null, strMailBody, false);
    //appForVacGrid.AllowPaging = true;
    //appForVacGrid.DataBind();
     if (!isMailSent)
     {
         titleLbl.Visible = true;
         titleLbl.Text = "MAIL HAS BEEN SENT TO THE SELECTED APPLICANTS";
         sendMailBtn.Visible = true;
     }
     else
     {
         titleLbl.Visible = true;
         titleLbl.Text = "MAIL SENDING FAIL.... TRY AGAIN LATER..";
         sendMailBtn.Visible = true;
     }
     appForVacGrid.DataSource = AppListTable;
     appForVacGrid.DataBind();
}

}

Answer 1

您正在綁定頁面 PageIndexChanging 事件上的網格，因此您的代碼首先無法將復選框的值更新為 session 中的 Datatable。 所以下次它將顯示選中的復選框..

Answer 2

希望這會對你有所幫助。 http://programming.top54u.com/post/Maintaining-Checkbox-state-while-GridView-Paging-in-C-sharp-ASP-Net.aspx