DataList Control in ASP.NET: Part 4

Abhimanyu K Vatsa
12y
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DataListControlinASP.NetPart4.zip

Introduction

In Part 3 of this article series we discussed how to use Template Fields but now in this article we will discuss how to select Data with a DataList Control.

Selecting Data with DataList Control

We use a DataList control as a menu by taking advantage of the control's SelectedValue property. For example, the page given below enables us to pick a book category and display a list of matching books.

select-data-with-data-list-control-in-vb.net.gif

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<style type="text/css">
    html
    {
        background-color:orange;
    }
    .content
    {
        margin:auto;
        width:600px;
        background-color:white;
    }
    .column
    {
        float:left;
        width:250px;
        padding:20px;
    }
    .books td
    {
        padding:10px;
    }
    a
    {
        padding:10px;
        color:red;
    }
    a:hover
    {
        background-color:Yellow;
    }
    </style>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div class="content">
    <div class="column">
    <asp:DataList
        id="rptBookCategories"
        DataSourceID="SqlDataSource1"
        Runat="server"
        CssClass="books">
        <ItemTemplate>
        <asp:HyperLink
            id="lnkMenu"
            Text='<%#Eval("NAME")%>'
            NavigateUrl='<%#Eval("CATEGORYID","Default.aspx?id={0}")%>'
            Runat="server" />
        </ItemTemplate>
    </asp:DataList>
    </div>
<div class="column">
    <asp:DataList
        id="rptBooks"
        DataSourceID="SqlDataSource2"
        Runat="server">
        <HeaderTemplate>
        <ul>
        </HeaderTemplate>
        <ItemTemplate>
        <li><%#Eval("NAME")%></li>
        </ItemTemplate>
        <FooterTemplate>
        </ul>
        </FooterTemplate>
    </asp:DataList>
    </div>
    <br style="clear:both" />
    </div>
        <br />
        <asp:SqlDataSource ID="SqlDataSource1" runat="server"
            ConnectionString="<%$ ConnectionStrings:DatabaseConnectionString1 %>"
            ProviderName="<%$ ConnectionStrings:DatabaseConnectionString1.ProviderName %>"
            SelectCommand="SELECT [CATEGORYID], [NAME] FROM [CATEGORIES]">
        </asp:SqlDataSource>
        <br />
        <asp:SqlDataSource ID="SqlDataSource2" runat="server"
            ConnectionString="<%$ ConnectionStrings:DatabaseConnectionString1 %>"
            ProviderName="<%$ ConnectionStrings:DatabaseConnectionString1.ProviderName %>"
            SelectCommand="SELECT [ID], [NAME], [AUTHOR] FROM [BOOKS] WHERE ID=@ID">
            <SelectParameters>
            <asp:QueryStringParameter
                Name="ID"
                QueryStringField="ID" />
            </SelectParameters>
        </asp:SqlDataSource>
    </form>
</body>
</html>

The preceding page contains two DataList controls. The first control displays a menu of book categories and the second DataList control displays a list of matching books in the database.
The first DataList contains a HyperLink inside its ItemTemplate, which looks like this:

<asp:HyperLink
            id="lnkMenu"
            Text='<%#Eval("NAME")%>'
            NavigateUrl='<%#Eval("CATEGORYID","Default.aspx?id={0}")%>'
            Runat="server" />

Note: Continued in the Next Part.

HAVE A GREAT CODING!