ListBox难题，高分，请高手相助

Question

代码如下
 <asp:ListBox ID="lbTank" runat="server" Width="120px" Height="60px"                              DataSourceID="ODSTank" DataTextField="Key"       DataValueField="Value"            SelectionMode="Multiple"></asp:ListBox> ListBox lbTank = ManageBoxFormView.FindControl("lbTank") as ListBox; //倒出罐
 string tempstr = "";
               for (int i = 0; i < lbTank.Items.Count; i++)
        {
                if (lbTank.Items[i].Selected)    //这儿始终只能读取到选中的第一个值，不知为什么
                {
                    if (string.IsNullOrEmpty(tempstr))
                    {
                        tempstr = lbTank.Items[i].Value;
                    }
                    else
                    {
                        tempstr = tempstr + "," + lbTank.Items[i].Value;
                    }
                }
        }

Answer 1

这没有默认选中的项，都是通过Ctrl键多选的，最多可能遍历50多次

Answer 2

控件的客户端状态，没有传送到服务器端。
可以试试直接使用lbTank.Items[i].Selected，不倒出罐验证一下。

Answer 3

控件本身有一个是否可多选的选项，记得默认的是单选状态，
需要更改一下
也许更改一下默认设置就行了。
try it

Answer 4

测试代码<asp:ListBox ID="ListBox1" runat="server" SelectionMode="Multiple">
        <asp:ListItem Text="1" Value="1"></asp:ListItem>
        <asp:ListItem Text="2" Value="2"></asp:ListItem>
        <asp:ListItem Text="3" Value="3"></asp:ListItem>
        <asp:ListItem Text="4" Value="4"></asp:ListItem>
        </asp:ListBox>
        <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
protected void Button1_Click(object sender, EventArgs e)
    {
        string item = "";
        for (int i = 0; i < ListBox1.Items.Count; i++)
        {
            if (ListBox1.Items[i].Selected)
            {
                if (string.IsNullOrEmpty(item))
                {
                    item = ListBox1.Items[i].Value;
                }
                else
                {
                    item += "," + ListBox1.Items[i].Value;
                }
            }
        }
        Response.Write(item);
    }没有问题啊，LZ试试

Answer 5

代码贴多点，你是在哪个事件里做的这循环，如果你默认选中的index=0当然会始终是那个

Answer 6

我这没有默认选中值，我单独测试那个ListBox没有问题，但是在我的整个程序中就出了无法读取选中的多个值

Answer 7

发现一个问题，将上面的cs代码改成下面
        ListBox lbTank = ManageBoxFormView.FindControl("lbTank") as ListBox;          string[] tempstr3 = Request.Form.GetValues(lbTank.UniqueID); //当我在里面选中两个就显示两个一样数据数组，而且始终是第一个，如果选中三个，可能是显示3个大小的第一个选中数据的数组

Answer 8

看看页面文件中Listbox里的数据值

Answer 9

DataValueField="Value"这个Value列的绑定值不应该有重复的值，否则永远只能停在重复值的第一个记录上。

Answer 10

但是事实是这样，我查一天，没找到什么原因，我来写个客户端javascript脚本看看选中值会不会重复

Answer 11

  lbTank 控件的绑定是不是在IsPostBack 之外？

Answer 12

我现在用Javascript测试确实能读到两个选中的值，我代码比较多，行帖一些出来
            <asp:UpdatePanel ID="ManageBoxUpdatePanel" runat="server" UpdateMode="Conditional">
                <ContentTemplate>
                    <div class="riPanel_content_div">
                        <div style="height: 7px;">
                        </div>
                        <dxrp:ASPxRoundPanel ID="RoundPanelForNew" runat="server" Width="100%" HeaderText="添加业务通知单">
                            <PanelCollection>
                                <dxrp:PanelContent>
                                    <asp:FormView ID="ManageBoxFormView" runat="server" OnItemInserted="ManageBoxFormView_ItemInserted"
                                        OnItemUpdated="ManageBoxFormView_ItemUpdated" DataSourceID="ManageBoxDataSource"
                                        OnDataBound="ManageBoxFormView_DataBound" DefaultMode="Insert" 
                                        OnItemInserting="ManageBoxFormView_ItemInserting">
  <EditItemTemplate>         //这个我就不贴了                                                                  </EditItemTemplate>
                                        <InsertItemTemplate>
                                            <div class="FormViewList">
                                                <%--编号--%>
                                                <asp:Label ID="Label4" runat="server" Text="编号:" Width="60px" AssociatedControlID="LabNoticeID"></asp:Label>
                                                <asp:Label ID="LabNoticeID" runat="server" Text='<%# Bind("NoticeID") %>' CssClass="labelLeft"
                                                    AssociatedControlID="Label4" Width="120px" />
                                            </div>
                                            <div class="FormViewList">
                                                                                                <asp:Label ID="Label1" runat="server" Text="类型:" Width="60px" AssociatedControlID="ddlNoticeType"></asp:Label>
                                                <asp:DropDownList ID="ddlNoticeType" runat="server" Width="128px" SelectedValue='<%# Bind("NoticeType") %>'
                                                    AutoPostBack="true" OnSelectedIndexChanged="NoticeType_SelectedIndexChanged">
                                                </asp:DropDownList>
                                                <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="ddlNoticeType"
                                                    ErrorMessage="类型必须选择" ValidationGroup="VGroup" Display="Dynamic">*</asp:RequiredFieldValidator>
                                                <cc1:CascadingDropDown ID="ajaxcddNoticeType" runat="server" TargetControlID="ddlNoticeType"
                                                    Category="noticetype" PromptText="选择类型" LoadingText="[Loading...]" ServicePath="StorageAutoComplete.asmx"
                                                    ServiceMethod="GetNoticeTypeForWareHouse" />
                                                <asp:Label ID="Label7" runat="server" Text="液化品:" Width="60px" AssociatedControlID="ddlOilInfo"></asp:Label>
                                                <asp:DropDownList ID="ddlOilInfo" runat="server" Width="128px" 
                                                    SelectedValue='<%# Bind("NoticeOilID") %>' 
                                                    onselectedindexchanged="ddlOilInfo_TextChanged" AutoPostBack="true">
                                                </asp:DropDownList>
                                                <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="ddlOilInfo"
                                                    ErrorMessage="液化品必须选择" ValidationGroup="VGroup" Display="Dynamic">*</asp:RequiredFieldValidator>
 
                                            </div>
                                               <div class="FormViewList">
                                                <asp:Label ID="Label17" runat="server" Text="储罐:" Width="60px" AssociatedControlID="lbTank"></asp:Label>
                                                   <asp:ListBox ID="lbTank" runat="server" Width="120px" Height="60px" 
                                                       DataSourceID="ODSTank" DataTextField="Key" DataValueField="Value" 
                                                       SelectionMode="Multiple"   ></asp:ListBox>
                                                       <asp:HiddenField ID="HDlbTank" runat="server" Value='<%# Bind("NoticeTool") %>' />
                       
                                                   <asp:Label ID="lblTankIDTit" runat="server" AssociatedControlID="lbInTank" 
                                                       Text="倒入罐:" Width="60px"></asp:Label>
                                                   <asp:ListBox ID="lbInTank" runat="server" Width="120px" Height="60px" 
                                                       DataSourceID="ODSTank" DataTextField="Key" DataValueField="Value" 
                                                       SelectionMode="Multiple"     ></asp:ListBox>
                                                       <asp:HiddenField ID="HDlbInTank" runat="server"  Value='<%# Bind("TankID") %>'/>
                       
                                                   
                                            </div>
                                                                                           <asp:ValidationSummary ID="ValidationSummary1" runat="server" EnableClientScript="true"
                                                    ValidationGroup="VGroup" />
                                            </div>
                                            <div class="FormViewButton">
                                                <table>
                                                    <tr>
                                                        <td>
                                                            <dxe:ASPxButton ID="InsertButton" runat="server" Text="添  加" ValidationGroup="VGroup"
                                                                CausesValidation="True" AutoPostBack="false">
                                                                <Image Url="~/App_Themes/Default/Icon/BtnAdd.png" UrlDisabled="~/App_Themes/Default/Icon/BtnAdd_Disable.png" />
                                                                <ClientSideEvents Click="
                                function(s, e) {
                                        if (Page_ClientValidate('VGroup')){
                                        aa();
                                        
                                        var lbTank=$get('ctl00_MainContent_RoundPanelForNew_ManageBoxFormView_lbTank')
                                         for(i=0;i<lbTank.length;i++)
                                         {
                                             if(lbTank.options[i].selected)
                                             {
                                                 alert(lbTank.options[i].text)
                                             }
                                         }
 
                                        
                                            $find('ManageBoxBehavior').hide(); 
                                            mainGrid.PerformCallback('InsertItem');
                                        }
                                     }" />
                                                            </dxe:ASPxButton>
                                                        </td>
                                                        <td>
                                                            <dxe:ASPxButton ID="UpdateCancelButton" runat="server" Text="取  消" CausesValidation="False"
                                                                CommandName="Cancel">
                                                                                                                       </dxe:ASPxButton>
                                                        </td>
                                                    </tr>
                                                </table>
                                            </div>
                                        </InsertItemTemplate>
                                    </asp:FormView>
                                </dxrp:PanelContent>
                            </PanelCollection>
                        </dxrp:ASPxRoundPanel>
                    </div>
                    <asp:ObjectDataSource ID="ManageBoxDataSource" runat="server" DataObjectTypeName="PPMIS.DAL.NoticeInfo"
                        InsertMethod="CreateWareHouseNotice" SelectMethod="ShowNoticeDetail" UpdateMethod="UpdateWareHouseNotice"
                        OldValuesParameterFormatString="original_{0}" TypeName="PPMIS.Operation.PPMISNoticeInfo">
                        <SelectParameters>
                            <asp:Parameter Name="noticeID" Type="String" />
                        </SelectParameters>
                    </asp:ObjectDataSource>
                    <asp:ObjectDataSource ID="ODSTank" runat="server" 
                        OldValuesParameterFormatString="original_{0}" SelectMethod="GetTankItem" 
                        TypeName="PPMIS.Operation.PPMISNoticeInfo">
                        <SelectParameters>
                            <asp:Parameter Name="oilID" Type="String" />
                        </SelectParameters>
                    </asp:ObjectDataSource>
                </ContentTemplate>
            </asp:UpdatePanel>
   

Answer 13

for(i=0;i <lbTank.length;i++) 
                                        { 
                                            if(lbTank.options[i].selected) 
                                            { 
                                                alert(lbTank.options[i].text) 
                                            } 
                                        } 
把这个options[i].value alert出来看看，是不是有相同的？

Answer 14

有可能是调用时机不对……LZ是写在了ManageBoxFormView_DataBound事件里吗？如果不是就可能会出错，我自己试了一下，完全没有问题啊

Answer 15

这个options[i].value alert看出没有相同，ManageBoxFormView_DataBound事件里没有和Listbox相关的东西啊，倒是在下面的事件中有这个出问题
 protected void ManageBoxFormView_ItemInserting(object sender, FormViewInsertEventArgs e)
    {
        ListBox lbTank = ManageBoxFormView.FindControl("lbTank") as ListBox; //倒出罐
        ListBox lbInTank = ManageBoxFormView.FindControl("lbInTank") as ListBox;
        string tempstr = "";
        for (int i = 0; i < lbTank.Items.Count; i++)
        {
                if (lbTank.Items[i].Selected)
                {
                    if (string.IsNullOrEmpty(tempstr))
                    {
                        tempstr = lbTank.Items[i].Value;
                    }
                    else
                    {
                        tempstr = tempstr + "," + lbTank.Items[i].Value;//无论选多少只能读到一个数据
                    }
                }
        }        string[] tempstr3 = Request.Form.GetValues(lbTank.UniqueID);//这个只能显示多个相同的数组 ，调试用的代码
        e.Values["NoticeTool"] = tempstr;
    }

Answer 16

有没有设置 AutoPostBack 属性为True？

Answer 17

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