CheckBoxList and Null Values

steve35719 · April 11th, 2006, 10:57 AM

I'm only trying to Update a record in a db. I can't even get the DetailsView to appear because I keep getting: 'CheckBoxList1' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value
I know it has to do with the Null value but how do I code for it? Also, how do I code my checkboxlist to keep the values the user selects and then update to the database. My selection gets lost and there is no update. I'm at wits end...

[u]First page with GridView:</u>

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <strong><span style="font-size: 10pt; font-family: Arial">webcharts<br />

        </span></strong>

    </div>
         <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1" DataKeyNames="Room" Font-Names="Arial">
            <Columns>
                <asp:HyperLinkField Text="Select" DataNavigateUrlFields="Room" DataNavigateUrlFormatString="Default2.aspx?Room={0 }" />
                <asp:BoundField DataField="Room" HeaderText="Room" SortExpression="Room" />
                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                <asp:BoundField DataField="Color" HeaderText="Color" SortExpression="Color" NullDisplayText="Red" />
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
            SelectCommand="SELECT * FROM [Fav]">

        </asp:SqlDataSource>

    </form>
</body>
</html>

[u]Second page with DetailsView</u>:

<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    Protected Sub DetailsView1_PageIndexChanging(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DetailsViewPageEventArgs )
        If Not IsPostBack Then
            Dim i As Integer
            Dim CheckBoxList1 As New CheckBoxList
            For i = 0 To CheckBoxList1.Items.Count - 1
                If CheckBoxList1.Items(i).Selected Then
                    Response.Write("You've selected " & CheckBoxList1.Items(i).Text & "<BR>")
                End If
            Next
        End If

    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <strong><span style="font-size: 10pt; font-family: Arial">webcharts<br />

        </span></strong>

    </div>
        <asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="False" DataSourceID="SqlDataSource1"
            Height="50px" Width="125px" DataKeyNames="Room" Font-Names="Arial" DefaultMode="Edit" OnPageIndexChanging="DetailsView1_PageIndexChangin g">
            <Fields>
                <asp:BoundField DataField="Room" HeaderText="Room" SortExpression="Room" ReadOnly="True" />
                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                <asp:TemplateField HeaderText="Color" SortExpression="Color" ConvertEmptyStringToNull="False">
                    <EditItemTemplate>
                         <asp:CheckBoxList ID="CheckBoxList1" runat="server" SelectedValue='<%# Bind("Color") %>'>
                            <asp:ListItem>Red</asp:ListItem>
                            <asp:ListItem>Green</asp:ListItem>
                            <asp:ListItem>Blue</asp:ListItem>
                        </asp:CheckBoxList>
                        <br />
                    </EditItemTemplate>
                    <InsertItemTemplate>
                        <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("Color") %>'></asp:TextBox>
                    </InsertItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="Label1" runat="server" Text='<%# Bind("Color") %>'></asp:Label>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:CommandField ShowEditButton="True" />
            </Fields>
        </asp:DetailsView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
            CancelSelectOnNullParameter="false"
            SelectCommand="SELECT * FROM [Fav] WHERE (Room=@Room)"
            UpdateCommand="UPDATE [Fav]
                            SET [Name]=@Name,
                                [Color]=@Color
                            WHERE [Room]=@Room">

            <SelectParameters>
            <asp:QueryStringParameter QueryStringField="Room" Name="Room" Type="String" />
            </SelectParameters>
            <UpdateParameters>
                <asp:Parameter Name="Name" Type="String" ConvertEmptyStringToNull="false" />
                <asp:Parameter Name="Color" Type="string" ConvertEmptyStringToNull="false" DefaultValue="Red"/>
            </UpdateParameters>

        </asp:SqlDataSource>
        <br />
         <asp:HyperLink ID="HyperLink1" Font-Names="arial" runat="server" NavigateUrl="~/Default.aspx">Return to Main</asp:HyperLink>
    </form>
</body>
</html>

Seems like it should be straightfoward. I just can't figure out how to code for it. Thanks for the help.

Greg

steve35719 · April 21st, 2006, 09:42 AM

Any thoughts?