因为SqlDataSource控件还是ObjectDatasource控件都没有实现IHierarchicalDataSource接口，所以Menu控件表现数据库数据，有两种方法:
因为SqlDataSource控件还是ObjectDatasource控件都没有实现IHierarchicalDataSource接口，所以Menu控件表现数据库数据，有两种方法:
一、创建自己的SqlHierachicalDataSource控件。就是继承IHierarchicalDataSource基类。
二、通过编程的方法为Menu控件创建菜单项目。
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<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Configuration" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<script runat="server">
/// <summary>
/// Only populate the menu when the page first loads
/// </summary>
void Page_Load()
{
if (!Page.IsPostBack)
PopulateMenu();
}
/// <summary>
/// Get the data from the database and create the top-level
/// menu items
/// </summary>
private void PopulateMenu()
{
DataTable menuData = GetMenuData();
AddTopMenuItems(menuData);
}
/// <summary>
/// Use a DataAdapter and DataTable to grab the database data
/// </summary>
/// <returns></returns>
private DataTable GetMenuData()
{
// Get Categories table
string selectCommand = "SELECT CategoryId,ParentId,Name FROM Categories";
string conString = WebConfigurationManager.ConnectionStrings["Categories"].ConnectionString;
SqlDataAdapter dad = new SqlDataAdapter(selectCommand, conString);
DataTable dtblCategories = new DataTable();
dad.Fill(dtblCategories);
return dtblCategories;
}
/// <summary>
/// Filter the data to get only the rows that have a
/// null ParentID (these are the top-level menu items)
/// </summary>
private void AddTopMenuItems(DataTable menuData)
{
DataView view = new DataView(menuData);
view.RowFilter = "ParentID IS NULL";
foreach (DataRowView row in view)
{
MenuItem newMenuItem = new MenuItem(row["Name"].ToString(), row["CategoryId"].ToString());
Menu1.Items.Add(newMenuItem);
AddChildMenuItems(menuData, newMenuItem);
}
}
/// <summary>
/// Recursively add child menu items by filtering by ParentID
/// </summary>
private void AddChildMenuItems(DataTable menuData, MenuItem parentMenuItem)
{
DataView view = new DataView(menuData);
view.RowFilter = "ParentID=" + parentMenuItem.Value;
foreach (DataRowView row in view)
{
MenuItem newMenuItem = new MenuItem(row["Name"].ToString(), row["CategoryId"].ToString());
parentMenuItem.ChildItems.Add(newMenuItem);
AddChildMenuItems(menuData, newMenuItem);
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<style type="text/css">
.menuItem
{
border:Solid 1px black;
width:100px;
padding:2px;
background-color:#eeeeee;
}
.menuItem a
{
color:blue;
}
.grid
{
margin-top:10px;
}
.grid td, .grid th
{
padding:10px;
}
</style>
<title>Menu Database</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Menu
id="Menu1"
Orientation="horizontal"
StaticMenuItemStyle-CssClass="menuItem"
DynamicMenuItemStyle-CssClass="menuItem"
Runat="server" />
<asp:GridView
id="grdProducts"
DataSourceID="srcProducts"
CssClass="grid"
AutoGenerateColumns="false"
Runat="server">
<Columns>
<asp:BoundField
DataField="ProductName"
HeaderText="Product" />
<asp:BoundField
DataField="Price"
HeaderText="Price"
DataFormatString="{0:c}" />
</Columns>
</asp:GridView>
<asp:SqlDataSource
id="srcProducts"
ConnectionString="<%$ ConnectionStrings:Categories %>"
SelectCommand="SELECT ProductName,Price FROM Products
WHERE CategoryId=@CategoryId"
Runat="server">
<SelectParameters>
<asp:ControlParameter
Name="CategoryId"
ControlID="Menu1" />
</SelectParameters>
</asp:SqlDataSource>
</div>
</form>
</body>
</html>
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