Professional ASP.NET 3.5 in C# and Visual Basic Part 20 pptx

The Calendar control also allows you to write out the date in a number of other formats, as detailed in the following list: ❑ ToFileTime: Converts the selection to the local operating sy

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Evjen c03.tex V2 - 01/28/2008 12:33pm Page 144

Chapter 3: ASP.NET Web Server Controls

Choosing a Date Format to Output from the Calendar

When you use theCalendar1_SelectionChangedevent, the selected date is written out using the

ToShortDateString()method The Calendar control also allows you to write out the date in a number

of other formats, as detailed in the following list:

❑ ToFileTime: Converts the selection to the local operating system file time:128571156000000000

❑ ToFileTimeUtc: Converts the selection to the operating system file time, but instead of using the

local time zone, the UTC time is used:128570976000000000

❑ ToLocalTime: Converts the current coordinated universal time (UTC) to local time:6/4/2008

7:00:00 PM

❑ ToLongDateString: Converts the selection to a human-readable string in a long format:

Thursday, June 05, 2008

❑ ToLongTimeString: Converts the selection to a time value (no date is included) of a long format:

12:00:00 AM

❑ ToOADate: Converts the selection to an OLE Automation date equivalent:39604

❑ ToShortDateString: Converts the selection to a human-readable string in a short format:

6/4/2008

❑ ToShortTimeString: Converts the selection to a time value (no date is included) in a short

for-mat: 12:00 AM

❑ ToString: Converts the selection to the following:6/4/2008 12:00:00 AM

❑ ToUniversalTime: Converts the selection to universal time (UTC):6/4/2008 6:00:00 AM

Making Day, Week, or Month Selections

By default, the Calendar control enables you to make single day selections You can use the

Selection-Modeproperty to change this behavior to allow your users to make week or month selections from the

calendar instead The possible values of this property includeDay,DayWeek,DayWeekMonth, andNone

TheDaysetting enables you to click a specific day in the calendar to highlight it (this is the default)

When you use the setting ofDayWeek, you can still make individual day selections, but you can also click

the arrow next to the week (see Figure 3-25) to make selections that consist of an entire week Using

the setting ofDayWeekMonthlets users make individual day selections or week selections A new arrow

appears in the upper-left corner of the calendar that enables users to select an entire month (also shown

in Figure 3-25) A setting ofNonemeans that it is impossible for the end user to make any selections,

which is useful for calendars on your site that are informational only

Working with Date Ranges

Even if an end user makes a selection that encompasses an entire week or an entire month, you get back

from the selection only the first date of this range If, for example, you allow users to select an entire

month and one selects July 2008, what you get back (usingToShortDateString()) is7/1/2008— the

first date in the date range of the selection That might work for you, but if you require all the dates in

the selected range, Listing 3-21 shows you how to get them

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Figure 3-25

Listing 3-21: Retrieving a range of dates from a selection

VB

<%@ Page Language="VB" %>

<script runat="server">

Protected Sub Calendar1_SelectionChanged(ByVal sender As Object, _

ByVal e As System.EventArgs)

Label1.Text = "<b><u>You selected the following date/dates:</u></b><br>"

For i As Integer = 0 To (Calendar1.SelectedDates.Count - 1)

Label1.Text += Calendar1.SelectedDates.Item(i).ToShortDateString() & _

"<br>"

</script>

<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head1" runat="server">

<title>Using the Calendar Control</title>

</head>

Continued

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<body>

<form id="form1" runat="server">

<div>

<asp:Calendar ID="Calendar1" runat="server"

OnSelectionChanged="Calendar1_SelectionChanged"

SelectionMode="DayWeekMonth">

</asp:Calendar><p>

<asp:Label ID="Label1" runat="server"></asp:Label></p>

</div>

</form>

</body>

</html>

C#

<%@ Page Language="C#" %>

protected void Calendar1_SelectionChanged(object sender, EventArgs e)

{

Label1.Text = "<b><u>You selected the following date/dates:</u></b><br>";

for (int i=0; i<Calendar1.SelectedDates.Count; i++) { Label1.Text += Calendar1.SelectedDates[i].ToShortDateString() +

"<br>";

} }

</script>

In this example, the Calendar control lets users make selections that can be an individual day, a week, or

even a month Using aFor Nextloop, you iterate through a selection by using theSelectedDates.Count

property The code produces the results shown in Figure 3-26

You can get just the first day of the selection by using the following:

VB

Calendar1.SelectedDates.Item(0).ToShortDateString()

C#

Calendar1.SelectedDates[0].ToShortDateString();

And you can get the last date in the selected range by using:

VB

Calendar1.SelectedDates.Item(Calendar1.SelectedDates.Count-1).ToShortDateString()

C#

Calendar1.SelectedDates[Calendar1.SelectedDates.Count-1].ToShortDateString();

As you can see, this is possible using theCountproperty of theSelectedDatesobject

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Figure 3-26

Modifying the Style and Behavior of Your Calendar

There is a lot to the Calendar control — definitely more than can be covered in this chapter One nice

thing about the Calendar control is the ease of extensibility that it offers Begin exploring new ways to

customize this control further by looking at one of the easiest ways to change it — applying a style to the control

Using Visual Studio, you can give the controls a new look-and-feel from the Design view of the page

you are working with Highlight the Calendar control and open the control’s smart tag to see the Auto

Format link That gives you a list of available styles that can be applied to your Calendar control

The Calendar control is not alone in this capability Many other rich controls offer a list of styles You

can always find this capability in the control’s smart tag.

Some of the styles are shown in Figure 3-27

In addition to changing the style of the Calendar control, you can work with the control during its ren-dering process The Calendar control includes an event calledDayRenderthat allows you to control how a single date or all the dates in the calendar are rendered Listing 3-22 shows an example of how to change one of the dates being rendered in the calendar

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Figure 3-27

Listing 3-22: Controlling how a day is rendered in the Calendar

VB

Protected Sub Calendar1_DayRender(ByVal sender As Object, _

ByVal e As System.Web.UI.WebControls.DayRenderEventArgs)

e.Cell.VerticalAlign = VerticalAlign.Top

If (e.Day.DayNumberText = "25") Then

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e.Cell.Controls.Add(New LiteralControl("<p>User Group Meeting!</p>"))

e.Cell.BorderColor = Drawing.Color.Black

e.Cell.BorderWidth = 1

e.Cell.BorderStyle = BorderStyle.Solid

e.Cell.BackColor = Drawing.Color.LightGray

End If

End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head1" runat="server">

<title>Using the Calendar Control</title>

</head>

<body>

<div>

<asp:Calendar ID="Calendar1" runat="server"

OnDayRender="Calendar1_DayRender" Height="190px" BorderColor="White"

Width="350px" ForeColor="Black" BackColor="White" BorderWidth="1px"

NextPrevFormat="FullMonth" Font-Names="Verdana" Font-Size="9pt">

<SelectedDayStyle ForeColor="White"

BackColor="#333399"></SelectedDayStyle>

<OtherMonthDayStyle ForeColor="#999999"></OtherMonthDayStyle>

<TodayDayStyle BackColor="#CCCCCC"></TodayDayStyle>

<NextPrevStyle ForeColor="#333333" VerticalAlign="Bottom"

Font-Size="8pt" Font-Bold="True"></NextPrevStyle>

<DayHeaderStyle Font-Size="8pt" Font-Bold="True"></DayHeaderStyle>

<TitleStyle ForeColor="#333399" BorderColor="Black" Font-Size="12pt"

Font-Bold="True" BackColor="White" BorderWidth="4px">

</TitleStyle>

</asp:Calendar>

</div>

</form>

</body>

</html>

C#

<%@ Page Language="C#" %>

protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)

{

e.Cell.VerticalAlign = VerticalAlign.Top;

if (e.Day.DayNumberText == "25")

{

e.Cell.Controls.Add(new LiteralControl("<p>User Group Meeting!</p>"));

e.Cell.BorderColor = System.Drawing.Color.Black;

e.Cell.BorderWidth = 1;

e.Cell.BorderStyle = BorderStyle.Solid;

e.Cell.BackColor = System.Drawing.Color.LightGray;

}

</script>

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In this example, you use a Calendar control with a little style to it When the page is built and run in the

browser, you can see that the 25th of every month in the calendar has been changed by the code in the

Calendar1_DayRenderevent The calendar is shown in Figure 3-28

Figure 3-28

The Calendar control in this example adds anOnDayRenderattribute that points to theCalendar1_

DayRenderevent The method is run for each of the days rendered in the calendar The class constructor

shows that you are not working with the typicalSystem.EventArgsclass, but instead with the

DayRen-derEventArgsclass It gives you access to each of the days rendered in the calendar

The two main properties from theDayRenderEventArgsclass areCellandDay TheCellproperty gives

you access to the space in which the day is being rendered, and theDayproperty gives you access to the

specific date being rendered in the cell

From the actions being taken in theCalendar1_DayRenderevent, you can see that both properties are

used First, theCellproperty sets the vertical alignment of the cell toTop If it didn’t, the table might

look a little strange when one of the cells has content Next, a check is made to see if the day being

rendered (checked with theDayproperty) is the 25th of the month If it is, theIf Thenstatement runs

using theCellproperty to change the styling of just that cell The styling change adds a control, as well

as makes changes to the border and color of the cell

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As you can see, working with individual dates in the calendar is fairly straightforward You can easily

give them the content and appearance you want

A nice feature of theDayproperty is that you can turn off the option to select a particular date or range

of dates by setting theDayproperty’sIsSelectableproperty toFalse:

VB

If (e.Day.Date < DateTime.Now) Then

e.Day.IsSelectable = False

End If

C#

if (e.Day.Date < DateTime.Now) {

e.Day.IsSelectable = false;

}

AdRotator Ser ver Control

Although Web users find ads rather annoying, advertising continues to be prevalent everywhere on the Web With the AdRotator control, you can configure your application to show a series of advertisements

to the end users With this control, you can use advertisement data from sources other than the standard XML file that was used with the previous versions of this control

If you are using an XML source for the ad information, first create an XML advertisement file The adver-tisement file allows you to incorporate some new elements that give you even more control over the

appearance and behavior of your ads Listing 3-23 shows an example of an XML advertisement file

Listing 3-23: The XML advertisement file

<?xml version="1.0" encoding="utf-8" ?>

<Advertisements

xmlns="http://schemas.microsoft.com/AspNet/AdRotator-Schedule-File">

<Ad>

<ImageUrl>book1.gif</ImageUrl>

<NavigateUrl>http://www.wrox.com</NavigateUrl>

<AlternateText>Visit Wrox Today!</AlternateText>

<Impressions>50</Impressions>

<Keyword>VB.NET</Keyword>

</Ad>

<Ad>

<ImageUrl>book2.gif</ImageUrl>

<NavigateUrl>http://www.wrox.com</NavigateUrl>

<AlternateText>Visit Wrox Today!</AlternateText>

<Impressions>50</Impressions>

<Keyword>XML</Keyword>

</Ad>

</Advertisements>

This XML file, used for storing information about the advertisements that appear in your application, has just a few elements detailed in the following table Remember that all elements are optional

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ImageUrl Takes a string value that indicates the location of the image to use

NavigateUrl Takes a string value that indicates the URL to post to when the image is clicked

AlternateText Takes a string value that is used for display either if images are turned off in the

client’s browser or if the image is not found

Impressions Takes a numerical value that indicates the likelihood of the image being selected

for display

Keyword Takes a string value that sets the category of the image in order to allow for the

filtering of ads

Now that the XML advertisement file is in place, you can simply use the AdRotator control to read from

this file Listing 3-24 shows an example of this in action

Listing 3-24: Using the AdRotator control as a banner ad

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

<title>AdRotator Page</title>

</head>

<body>

<asp:AdRotator ID="AdRotator1" runat="server"

AdvertisementFile="MyAds.xml" />

<p>Lorem ipsum dolor sit

amet, consectetuer adipiscing elit Duis vel justo Aliquam adipiscing In mattis volutpat urna Donec adipiscing, nisl eget dictum egestas, felis nulla ornare ligula, ut bibendum pede augue

eu augue Sed vel risus nec urna pharetra imperdiet Aenean semper Sed ullamcorper auctor sapien Suspendisse luctus Ut ac nibh Nam lorem Aliquam dictum aliquam purus.</p>

</form>

</body>

</html>

The example shows the ad specified in the XML advertisement file as a banner ad at the top of the page

You are not required to place all your ad information in the XML advertisement file Instead, you can

use another data source to which you bind the AdRotator For instance, you bind the AdRotator to a

SqlDataSourceobject that is retrieving the ad information from SQL Server in the following fashion:

<asp:AdRotator ID="AdRotator1" runat="server"

DataSourceId="SqlDataSource1" AlternateTextField="AlternateTF"

ImageUrlField="Image" NavigateUrlField="NavigateUrl" />

TheAlternateTextField,ImageUrlField, andNavigateUrlFieldproperties point to the column names

that are used in SQL Server for those items

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The Xml Ser ver Control

The Xml server control provides a means of getting XML and transforming it using an XSL style

sheet The Xml control can work with your XML in a couple of different ways The simplest method

is by using the construction shown in Listing 3-25 This control is covered in more detail in Chapter 10

Listing 3-25: Displaying an XML document

<asp:Xml ID="Xml1" runat="server" DocumentSource="~/MyXMLFile.xml"

TransformSource="MyXSLFile.xslt"></asp:Xml>

This method takes only a couple of attributes to make it work:DocumentSource, which points to the path

of the XML file, andTransformSource, which provides the XSLT file to use in transforming the XML

document

The other way to use the Xml server control is to load the XML into an object and then pass the object to the Xml control, as illustrated in Listing 3-26

Listing 3-26: Loading the XML file to an object before providing it to the Xml control

VB

Dim MyXmlDoc as XmlDocument = New XmlDocument()

MyXmlDoc.Load(Server.MapPath("Customers.xml"))

Dim MyXslDoc As XslCompiledTransform = New XslCompiledTransform()

MyXslDoc.Load(Server.MapPath("CustomersSchema.xslt"))

Xml1.Document = MyXmlDoc

Xml1.Transform = MyXslDoc

C#

XmlDocument MyXmlDoc = new XmlDocument();

MyXmlDoc.Load(Server.MapPath("Customers.xml"));

XslCompiledTransform MyXsltDoc = new XslCompiledTransform();

MyXsltDoc.Load(Server.MapPath("CustomersSchema.xslt"));

Xml1.Document = MyXmlDoc;

Xml1.Transform = MyXslDoc;

To make this work, you have to ensure that theSystem.XmlandSystem.Xml.Xslnamespaces are

imported into your page The example loads both the XML and XSL files and then assigns these files

as the values of theDocumentandTransformproperties

Panel Ser ver Control

The Panel server control encapsulates a set of controls you can use to manipulate or lay out your ASP.NET pages It is basically a wrapper for other controls, enabling you to take a group of server controls along with other elements (such as HTML and images) and turn them into a single unit

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