ASP.NET 4 Unleased - p 25 ppsx

WARNING If you create an event handler for the AdCreated event and you cache the page, the content rendered by the AdRotator control is also cached.. When handling the AdCreated event, u

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WARNING

If you create an event handler for the AdCreated event and you cache the page, the

content rendered by the AdRotator control is also cached When handling the

AdCreated event, use partial page caching to cache only part of a page and not the

AdRotator control itself

The page in Listing 4.14 displays a banner advertisement with the AdRotator control The

page includes an event handler for the AdRotator control’s AdCreated event

LISTING 4.14 AdRotatorTrack.aspx

<%@ Page Language=”C#” %>

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN”

“http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

protected void AdRotator1_AdCreated(object sender, AdCreatedEventArgs e)

{

// Update Impressions

srcAds.InsertParameters[“AdId”].DefaultValue =

➥e.AdProperties[“Id”].ToString();

srcAds.Insert();

// Change NavigateUrl to redirect page

e.NavigateUrl = “~/AdHandler.ashx?id=” + e.AdProperties[“Id”].ToString();

}

</script>

<title>AdRotator Track</title>

</head>

<body>

<div>

<asp:AdRotator

id=”AdRotator1”

DataSourceID=”srcAds”

OnAdCreated=”AdRotator1_AdCreated”

Runat=”server” />

<asp:SqlDataSource

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AttachDbFileName=|DataDirectory|AdListDB.mdf;User Instance=True”

SelectCommand=”SELECT Id, ImageUrl, Width, Height, NavigateUrl,

➥AlternateText,Keyword, Impressions

FROM AdList”

InsertCommand=”INSERT AdStats (AdId, EntryDate, Type) VALUES (@AdId,

➥GetDate(), 0)”

Runat=”server”>

<asp:Parameter Name=”AdId” Type=”int32” />

</InsertParameters>

</asp:SqlDataSource>

</div>

</form>

</body>

</html>

The AdCreated event handler does two things First, it inserts a new record into a database

table named AdStats, which records an advertisement impression Second, the handler

modifies the NavigateUrl so that the user is redirected to a handler named

AdHandler.ashx

The AdStats database table looks like this:

The Type column records the type of entry The value 0 represents an advertisement

impression, and the value 1 represents an advertisement transfer

When you click an advertisement, you link to a file named AdHandler.ashx This file is

contained in Listing 4.15

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LISTING 4.15 AdHandler.ashx

<%@ WebHandler Language=”C#” Class=”AdHandler” %>

using System;

using System.Web;

using System.Data;

using System.Data.SqlClient;

public class AdHandler : IHttpHandler {

const string conString = @”Server=.\SQLExpress;Integrated Security=True;

AttachDbFileName=|DataDirectory|AdListDB.mdf;User Instance=True”;

public void ProcessRequest (HttpContext context)

{

int AdId = Int32.Parse(context.Request[“Id”]);

SqlConnection con = new SqlConnection(conString);

string navigateUrl = String.Empty;

using (con)

{

con.Open();

UpdateTransferStats(AdId, con);

navigateUrl = GetNavigateUrl(AdId, con);

}

if (!String.IsNullOrEmpty(navigateUrl))

context.Response.Redirect(navigateUrl);

}

void UpdateTransferStats(int advertisementId, SqlConnection con)

{

string cmdText = “INSERT AdStats (AdId, EntryDate, Type) VALUES “ +

“(@AdId, GetDate(), 1)”;

SqlCommand cmd = new SqlCommand(cmdText, con);

cmd.Parameters.AddWithValue(“@AdId”, advertisementId);

cmd.ExecuteNonQuery();

}

string GetNavigateUrl(int advertisementId, SqlConnection con)

{

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return cmd.ExecuteScalar().ToString();

}

public bool IsReusable

{

get

{

return false;

}

The handler in Listing 4.15 performs two tasks First, it inserts a new record into the

AdStats database table, recording that a transfer is taking place Next, it grabs the

NavigateUrl from the AdList database table and sends the user to the advertiser’s website

The final page displays advertiser statistics from the AdStats database table (see Figure

4.9) This page is contained in Listing 4.16

FIGURE 4.9 Displaying advertiser statistics

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LISTING 4.16 AdRotatorStats.aspx

.grid td,.grid th

{

border-bottom:solid 1px black;

padding:5px;

}

</style>

<title>AdRotator Statistics</title>

</head>

<body>

<div>

<h1>Advertisement Statistics</h1>

Impressions represent the number of times an advertisement has been viewed

Transfers represent the number of times an advertisement has been clicked

<h2>Impressions</h2>

<asp:GridView

id=”grdImpressions”

DataSourceID=”srcImpressions”

AutoGenerateColumns=”false”

GridLines=”None”

CssClass=”grid”

Runat=”server”>

<asp:BoundField

DataField=”AdId”

HeaderText=”Advertisement Id” />

<asp:BoundField

DataField=”Impressions”

HeaderText=”Impressions” />

</Columns>

</asp:GridView>

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SelectCommand=”SELECT AdId,Count(*) As Impressions

FROM AdStats

WHERE Type=0

GROUP BY AdId

ORDER BY Impressions DESC”

<h2>Transfers</h2>

<asp:GridView

id=”grdTransfers”

DataSourceID=”srcTransfers”

AutoGenerateColumns=”false”

GridLines=”None”

CssClass=”grid”

Runat=”server”>

<asp:BoundField

DataField=”AdId”

HeaderText=”Advertisement Id” />

<asp:BoundField

DataField=”Transfers”

HeaderText=”Transfers” />

</Columns>

</asp:GridView>

<asp:SqlDataSource

id=”srcTransfers”

ConnectionString=”Server=.\SQLExpress;Integrated Security=True;

SelectCommand=”SELECT AdId,Count(*) As Transfers

FROM AdStats

WHERE Type=1

GROUP BY AdId

ORDER BY Transfers DESC”

</div>

</form>

</body>

</html>

The page in Listing 4.16 contains two GridView controls bound to two SqlDataSource

controls The first GridView displays statistics on impressions, and the second GridView

displays statistics on transfers

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Displaying Different Page Views

The MultiView control enables you to hide and display different areas of a page This

control is useful when you need to create a tabbed page It is also useful when you need to

divide a long form into multiple forms

The MultiView control contains one or more View controls You use the MultiView control

to select a particular View control to render (The selected View control is the Active

View.) The contents of the remaining View controls are hidden You can render only one

View control at a time

The MultiView control supports the following properties (this is not a complete list):

MultiView control

The MultiView control also supports the following methods:

Finally, the MultiView control supports the following event:

The View control does not support any special properties or methods Its primary purpose

is to act as a container for other controls However, the View control does support the

following two events:

control

Displaying a Tabbed Page View

When you use the MultiView control with the Menu control, you can create a tabbed page

view (To make it look pretty, you need to use some CSS.)

For example, the page in Listing 4.17 contains a MultiView control with three View

controls The Menu control switches between the View controls (see Figure 4.10)

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LISTING 4.17 MultiViewTabs.aspx

protected void Menu1_MenuItemClick(object sender, MenuEventArgs e)

{

int index = Int32.Parse(e.Item.Value);

MultiView1.ActiveViewIndex = index;

}

</script>

html

{

background-color:silver;

}

.tabs

{

FIGURE 4.10 Displaying a tabbed page with the MultiView control

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position:relative;

top:1px;

left:10px;

}

.tab

{

border:solid 1px black;

background-color:#eeeeee;

padding:2px 10px;

}

.selectedTab

{

background-color:white;

border-bottom:solid 1px white;

}

.tabContents

{

border:solid 1px black;

padding:10px;

background-color:white;

}

</style>

<title>MultiView Tabs</title>

</head>

<body>

<div>

<asp:Menu

id=”Menu1”

Orientation=”Horizontal”

StaticMenuItemStyle-CssClass=”tab”

StaticSelectedStyle-CssClass=”selectedTab”

CssClass=”tabs”

OnMenuItemClick=”Menu1_MenuItemClick”

Runat=”server”>

<Items>

<asp:MenuItem Text=”Tab 1” Value=”0” Selected=”true” />

<asp:MenuItem Text=”Tab 2” Value=”1” />

<asp:MenuItem Text=”Tab 3” Value=”2” />

</Items>

</asp:Menu>

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Runat=”server”>

<asp:View ID=”View1” runat=”server”>

<br />This is the first view

</asp:View>

<br />This is the second view

</asp:View>

<br />This is the third view

</asp:View>

</asp:MultiView>

</div>

</form>

</body>

</html>

In Listing 4.17, the Menu control is associated with a CSS class named tabs This class

rela-tively positions the Menu control down one pixel to merge the bottom border of the Menu

control with the top border of the <div> tag that contains the MultiView Because the

selected tab has a white bottom border, the border between the selected tab and the tab

contents disappears

Displaying a Multipart Form

You can use the MultiView control to divide a large form into several subforms You can

associate particular commands with button controls contained in a MultiView When the

button is clicked, the MultiView changes the active view

The MultiView control recognizes the following commands:

control’s CommandArgument

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