可以看到，当选择dropdownlist中的不同商品时，gridview会显示涉及该商品的不同订单的详细资料．程序的代码如下：
＜form id="form1" runat="server"＞
＜div＞
＜h2＞You are Viewing Order Detail Information for Orders
that Have Included Shipments of the Selected Product＜/h2＞
＜asp:SqlDataSource ID="productListingDataSource"
Runat="server" ConnectionString=
"＜%$ ConnectionStrings:NWConnectionString %＞"
SelectCommand="SELECT [ProductID],
[ProductName] FROM [Products]"＞
＜/asp:SqlDataSource＞
＜asp:DropDownList ID="productSelector" Runat="server"
DataSourceID="productListingDataSource"
DataTextField="ProductName" DataValueField="ProductID"
AutoPostBack="True"＞
＜/asp:DropDownList＞
＜asp:SqlDataSource ID="orderDetailsForProduct" Runat="server"
SelectCommand="SELECT [OrderID], [ProductID], [UnitPrice],
[Quantity] FROM [Order Details] WHERE ([ProductID] =
@ProductID)"
ConnectionString=
"＜%$ ConnectionStrings:NWConnectionString%＞"
DataSourceMode="DataReader"＞
＜SelectParameters＞
＜asp:ControlParameter Name="ProductID" Type="Int32"
ControlID="productSelector"
PropertyName="SelectedValue"＞＜/asp:ControlParameter＞
＜/SelectParameters＞
＜/asp:SqlDataSource＞＜asp:GridView ID="orderDetailsGridView"
Runat="server" DataSourceID="orderDetailsForProduct"
AutoGenerateColumns="False" DataKeyNames="OrderID"
BorderWidth="1px" BackColor="LightGoldenrodYellow"
GridLines="None" CellPadding="2" BorderColor="Tan"
ForeColor="Black"＞
＜FooterStyle BackColor="Tan"＞＜/FooterStyle＞
＜PagerStyle ForeColor="DarkSlateBlue"
HorizontalAlign="Center" BackColor="PaleGoldenrod"＞
＜/PagerStyle＞
＜HeaderStyle Font-Bold="True"
BackColor="Tan"＞＜/HeaderStyle＞
＜AlternatingRowStyle
BackColor="PaleGoldenrod"＞＜/AlternatingRowStyle＞
＜Columns＞
＜asp:BoundField ReadOnly="True" HeaderText="Order ID"
InsertVisible="False" DataField="OrderID"
SortExpression="OrderID"＞
＜ItemStyle HorizontalAlign="Center"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜asp:BoundField HeaderText="Quantity"
DataField="Quantity" SortExpression="Quantity"
DataFormatString="{0:d}"＞
＜ItemStyle HorizontalAlign="Right"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜asp:BoundField HeaderText="Unit Price"
DataField="UnitPrice" SortExpression="UnitPrice"
DataFormatString="{0:c}"＞
＜ItemStyle HorizontalAlign="Right"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜/Columns＞
＜SelectedRowStyle ForeColor="GhostWhite"
BackColor="DarkSlateBlue"＞＜/SelectedRowStyle＞
＜/asp:GridView＞
＜/div＞
＜/form＞
＜div＞
＜h2＞You are Viewing Order Detail Information for Orders
that Have Included Shipments of the Selected Product＜/h2＞
＜asp:SqlDataSource ID="productListingDataSource"
Runat="server" ConnectionString=
"＜%$ ConnectionStrings:NWConnectionString %＞"
SelectCommand="SELECT [ProductID],
[ProductName] FROM [Products]"＞
＜/asp:SqlDataSource＞
＜asp:DropDownList ID="productSelector" Runat="server"
DataSourceID="productListingDataSource"
DataTextField="ProductName" DataValueField="ProductID"
AutoPostBack="True"＞
＜/asp:DropDownList＞
＜asp:SqlDataSource ID="orderDetailsForProduct" Runat="server"
SelectCommand="SELECT [OrderID], [ProductID], [UnitPrice],
[Quantity] FROM [Order Details] WHERE ([ProductID] =
@ProductID)"
ConnectionString=
"＜%$ ConnectionStrings:NWConnectionString%＞"
DataSourceMode="DataReader"＞
＜SelectParameters＞
＜asp:ControlParameter Name="ProductID" Type="Int32"
ControlID="productSelector"
PropertyName="SelectedValue"＞＜/asp:ControlParameter＞
＜/SelectParameters＞
＜/asp:SqlDataSource＞＜asp:GridView ID="orderDetailsGridView"
Runat="server" DataSourceID="orderDetailsForProduct"
AutoGenerateColumns="False" DataKeyNames="OrderID"
BorderWidth="1px" BackColor="LightGoldenrodYellow"
GridLines="None" CellPadding="2" BorderColor="Tan"
ForeColor="Black"＞
＜FooterStyle BackColor="Tan"＞＜/FooterStyle＞
＜PagerStyle ForeColor="DarkSlateBlue"
HorizontalAlign="Center" BackColor="PaleGoldenrod"＞
＜/PagerStyle＞
＜HeaderStyle Font-Bold="True"
BackColor="Tan"＞＜/HeaderStyle＞
＜AlternatingRowStyle
BackColor="PaleGoldenrod"＞＜/AlternatingRowStyle＞
＜Columns＞
＜asp:BoundField ReadOnly="True" HeaderText="Order ID"
InsertVisible="False" DataField="OrderID"
SortExpression="OrderID"＞
＜ItemStyle HorizontalAlign="Center"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜asp:BoundField HeaderText="Quantity"
DataField="Quantity" SortExpression="Quantity"
DataFormatString="{0:d}"＞
＜ItemStyle HorizontalAlign="Right"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜asp:BoundField HeaderText="Unit Price"
DataField="UnitPrice" SortExpression="UnitPrice"
DataFormatString="{0:c}"＞
＜ItemStyle HorizontalAlign="Right"＞＜/ItemStyle＞
＜/asp:BoundField＞
＜/Columns＞
＜SelectedRowStyle ForeColor="GhostWhite"
BackColor="DarkSlateBlue"＞＜/SelectedRowStyle＞
＜/asp:GridView＞
＜/div＞
＜/form＞
