Microsoft ASP Net 3.5 Step By Step (phần 8) ppt

Chapter 8 A Consistent Look and Feel 181 Master Pages offer signiﬁ cant improvements over earlier versions of classic ASP and ASP.NET for developing a common look and feel among all the

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Chapter 8 A Consistent Look and Feel 181

Master Pages offer signiﬁ cant improvements over earlier versions of classic ASP and ASP.NET for developing a common look and feel among all the pages in your application Of course, you may use multiple Master Pages in a project, and you may also nest them

A second way to help manage the look and feel of your application is ASP.NET Themes

Themes

Master Pages control the general layout of a series of pages within an application However, there are other elements (those that are subject to change between pages) that you might like to have remain constant Themes provide a means of applying common styles to the ele-ments on each page in your site

If you’re familiar with Cascading Style Sheets (CSS), you will feel very at home with Themes The two techniques are similar because through both techniques you may deﬁ ne the visual styles for your Web pages Themes go a step beyond CSS You may use Themes to specify styles, graphics, and even CSS ﬁ les within the pages of your applications When available, you may apply ASP.NET Themes at the application, page, or server control level

Themes are represented as text-based style defi nitions in ASP.NET ASP.NET already includes a number of Themes straight out of the box You’ll fi nd these Themes located at C:\WINDOWS\Microsoft.NET\Framework\vxxxxx\ASP.NETClientFiles\Themes ASP.NET includes some pre-defi ned Themes (note the “vxxxxx” indicates the current version of the NET Framework you’re using, most likely “v3.5” at the time this was written) In addition, you may defi ne and use your own Themes

The following exercise shows how to create and use a Theme

Creating and using a Theme

1 Add a new form to the MasterPagesSite project Name the page UseThemes.aspx Turn

off the Select Master Page check box if it happens to be turned on before you commit

to creating the page

2 Add a Theme folder to your project Highlight the Web site node in the Solution

Explorer Click the right mouse button and select Add ASP.NET Folder Select Theme This will create an App_Themes directory for you

3 Create a Default Themes folder under the App_Themes folder Click the right mouse

button on the App_Themes folder Select Add Folder, and then select Theme Folder from the menu Rename the folder from Theme1 to Default

4 Add a new style sheet to the Theme1 folder Click the right mouse button on the

Theme1 folder and select Add New Item Select the Style Sheet template Name the

Style sheet Default.css

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182 Part II Advanced Features

5 Build the style sheet The default style sheet includes only a body tag When the style

sheet is open in Visual Studio, select Add Style Rule from the Styles menu You may click the right mouse button on the Elements node to modify the style for the node For example, if you want to change the style of the <h1> tag, you would click the right

mouse button on the Elements node and select Add Style Rule To add a style for the

<h1> tag, select it from the list of elements and move it into the Style Rule Hierarchy

by clicking the > button, as shown here Then click OK

To modify the style, click on the H1 node in the CSS outline page and select Style in the Properties window Click the “ ” button to activate the Modify Style dialog box:

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Chapter 8 A Consistent Look and Feel 183

The sample application included with the CD sets the font to Arial Black with an

underscore

6 Now test the Theme by declaring it in the page and by typing a heading with <h1>

tags, like so:

<%@ Page Language="C#" AutoEventWireup="true"

CodeFile="UseThemes.aspx.cs"

"Theme=Default"

trace="false" Inherits="UseThemes" %>

<%@ Register Src="Banner.ascx" TagName="Banner" TagPrefix="uc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"

Here’s how the themed page appears in the browser with the new theme (the <h1> tag

set to the new font and set to use the underline in this example):

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7 Add another Theme to the project Name the Theme SeeingRed That is, create a new

Theme folder and add a new style sheet of the same name Make the <h1> tag use a

red color font this time Then change the Theme used by the page to SeeingRed (you can also set the theme in the Properties window in Visual Studio):

<%@ Page Language="C#" AutoEventWireup="true"

CodeFile="UseThemes.aspx.cs"

Theme="SeeingRed"

trace="false" Inherits="UseThemes" %>

Surf to the page to see the <h1> tag printed in red

This is just a taste of the kinds of things you can do by providing Themes for a page Once a Theme is deﬁ ned, you may apply it by declaring it as part of the Page declaration or by inter-

cepting the PreInit event and changing the Theme property in the page to a valid Theme

Going hand in hand with Themes are Skins Let’s look at those

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Chapter 8 A Consistent Look and Feel 185 Skins

Skins complement Master Pages and Themes as a way to manage the style of your Web site Using Skins is almost like combining WebControl-based controls with CSS Another way to

think of Skins is as a way to set certain properties of a control as a group For example, you may want to deﬁ ne different coloring schemes for a control such as the TextBox control The Calendar control is also a good example because it’s so rich By providing Skins for controls,

you can have a number of different appearance options for various controls at your disposal without having to go into detail and manage the control properties one by one

You have actually used Skins already Many server-side controls already support style plates For example, when working with the TreeView earlier, you saw that you could apply

tem-one of several styles to it Earlier in this chapter, we looked at applying a set of color butes to the Menu control when we chose the “classic” style from the AutoFormat control

attri-option menu In this section, we’ll see how Skins work and how to apply them

Skin fi les defi ne specifi c controls and the attributes that apply to them That is, a skin fi le contains server-side control declarations The Skin fi le’s job is to preset the style properties for the control Skin fi les reside in named Theme folders for an application, accompanied by any necessary CSS fi les

The following exercise illustrates how to create Skins for some controls on your Web site

Create a Skin

1 Create a Skin ﬁ le by clicking the right mouse button on the SeeingRed folder in the

App_Theme node on the Solution Explorer and selecting Add New Item Choose Skin

File from the templates Name the ﬁ le SeeingRed.skin

2 In the SeeingRed.skin ﬁ le, pre-declare some controls for which you’d like to have default

property values set For example, the following SeeingRed.skin ﬁ le declares default erties for some controls These controls have their various colors defaulting to assorted shades of red

prop-<asp:Label runat="server" ForeColor="red"

Font-Size="14pt" Font-Names="Verdana" />

<asp:button runat="server" borderstyle="Solid"

borderwidth="2px" bordercolor="#ff0000" backcolor="#cc0000"/>

<asp:CheckBoxList runat=server ForeColor="#ff0000" />

<asp:RadioButtonList runat=server ForeColor="#ff9999" />

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3 Now add those controls for which you’ve pre-declared attributes in the Skin ﬁ le onto

the UseThemes.aspx page to see how the SeeingRed.skin ﬁ le applies The effect in the following graphic shows the red colored controls as a lighter gray You will no doubt see the effect when running the sample application

The SeeingRed.skin ﬁ le will automatically be applied by declaring the SeeingRed Theme within the page You may also prescribe different Skins at runtime within the page’s

PreInit handler, and you can apply separate Skins to each control

Summary

One of the most often requested features for ASP.NET has been to support a common look and feel for a site The Master Pages feature within ASP.NET pushes this capability to the forefront and makes developing a set of pages with similar aspects a very doable proposition

In addition to Master Pages, ASP.NET Themes represent a way to apply global style attributes

to all the pages in your application

ASP.NET also supports specifying default values for specifi c server-side controls through a Skin fi le Skins offer a fi ner-grained approach to applying styles in a control-centric manner

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Chapter 8 A Consistent Look and Feel 187Chapter 8 Quick Reference

Deﬁ ne a page that will represent the consistent

look and feel of a series of pages in a Web site

Add a Master Page to the site.

Create a page based on the Master Page Check the Select Master Page check box when creating

forms for a site.

Add elements to the Master Page that will

show up in pages based on the Master Page

Place elements outside the area represented by the content pane

Add individual elements to content pages Add elements within the content page shown on the page Create a Theme for a page Add a new Theme folder to the App_Themes folder within

your application Use a Cascading Style Sheet (CSS) to

de-ﬁ ne styles and classes for the Theme.

Apply a Theme to a page Set the Theme property within the Page Directive

OR Set the Theme property within the page during the page’s

PreInit event.

Create a Skin Create a text ﬁ le within a Theme folder Simply make the

ﬁ le have a skin extension Add control declarations with their properties set to default values.

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189

Chapter 9

Confi guration

After completing this chapter, you will be able to

Understand the way NET handles conﬁ guration

Apply conﬁ guration settings to ASP.NET applications

Manage ASP.NET conﬁ guration using the ASP.NET Administration tool

Manage ASP.NET conﬁ guration using the MMC Snap-in

This chapter introduces how ASP.NET manages its conﬁ guration information It gives a taste

of how ASP.NET conﬁ guration works We’ll revisit ASP.NET conﬁ guration in later chapters ASP.NET is a feature-rich system for developing and deploying Web sites The features we’ll see in more detail as we examine ASP.NET further include some of the following:

ex-or using SQL Server) You may also conﬁ gure the lifetime of your session state and how your application tracks the session state (via a cookie or some other method)

A second feature controlled through the conﬁ guration ﬁ le is caching output When you cache the content of your site, you may vary the lifetime of your cached content and where it’s cached (on the server, on the client, or on the proxy)

For both these features (and others), the confi guration options are governed by confi tion fi les Here, we fi rst examine the nature of Windows confi guration and then look specifi -cally at how ASP.NET handles confi guration In ASP.NET 1.x, modifying the confi guration of your application meant editing the XML-based confi guration fi le by hand Fortunately, more recent ASP.NET versions offer two tools that make confi guration a much easier proposition One tool is the ASP.NET confi guration tab available through the normal Internet Information Services (IIS) confi guration panel The second tool is the Web Site Administration Tool, avail-able through the Web Site, ASP.NET Confi guration menu in Visual Studio We’ll cover these tools as well

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gura-190 Part II Advanced Features

Windows Confi guration

Every computing platform needs a conﬁ guration mechanism to control the behavior of the platform On any platform, a number of various parameters can govern how the operat-ing system and programs operate The parameters often need to be modiﬁ ed, perhaps to tune performance or tailor security or even just to control normal operation For example, Windows provides an environment variable named PATH that controls the search path for

executable programs Other environment variables include one named TEMP (controls the

location of temporary ﬁ les) and USERPROFILE (identiﬁ es the location of the current user’s

proﬁ le information)

In addition to operating system variables, individual applications may require different tings specifi c to that program For example, many applications require a specifi c version of Windows or that specifi c dynamic link libraries (DLLs) be available These actions may vary from one installation to the next, and it’s not a good idea to hard-code the settings into your application Instead, you store values in a secondary fi le that accompanies the application During the early days of Windows, “initialization fi les” (.INI fi les) served to not only confi gure individual applications but also Windows itself; there is even a set of Windows Application Programming Interface (API) functions for managing confi guration parameters The fi les contain a name/value pair that dictates a property and its associated setting For example, the name/value pair in Win.INI that turns on Object Linking and Embedding (OLE) messaging looks like

fi les may simply be copied In addition, the account that runs most ASP.NET sites is specifi cally confi gured to be opted out of the Registry to secure the site from hacks and attacks

NET Confi guration

NET confi guration fi les are well-formed XML fi les whose vocabulary is understood by the NET runtime You can see a listing of all the confi guration fi les by looking in the confi gura-tion directory We’ll see that directory in just a minute

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Chapter 9 Confi guration 191

The NET runtime reads these confi guration fi les into memory as necessary to set the various NET runtime parameters For example, web.confi g is loaded when ASP.NET applications are started The fi rst confi guration fi le we’ll take a look at is machine.confi g

Machine.Confi g

The default NET conﬁ guration for your machine is declared within a ﬁ le named

machine.confi g You can ﬁ nd machine.conﬁ g within the directory C:\Windows\Microsoft

.NET\Framework\vxxxxx\conﬁ g Machine.conﬁ g sets the default NET application behaviors for the entire machine

Recent NET versions made a number of improvements to the machine.confi g arrangement .NET 1.x lumped all of machine.confi g into a single fi le—even comments and confi guration information for systems not in use on the specifi c machine (browser information, for ex-ample, even though the machine may not have been hosting ASP.NET) The current version

of machine.confi g is trimmed down substantially from version 1.x The comments have been moved to a separate fi le named machine.confi g.comments, and separate browser defi ni-

tion capability fi les have been moved to separate confi guration fi les This is important to know because the machine.confi g comments are sometimes more useful as documentation for confi guring NET than the regular online documentation As you confi gure your various ASP.NET applications, the machine.confi g comments should be the fi rst place you look for information

Confi guration Section Handlers

At the top of machine.confi g you’ll see a number of Confi guration Section Handlers Each of these handlers understands a specifi c vocabulary for confi guring NET (and ultimately ASP.NET) While machine.confi g controls the settings for the entire machine, ASP.NET applica-tions rely on fi les named web.confi g to manage confi guration We’ll see much more about

web.config shortly However, for now here is a small snippet that you might find in a web.confi g fi le for a specifi c application:

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to expire after 25 minutes, and to track session information using a session ID embedded within the request Universal Resource Indicator (URI) We’ll look at session state in detail in Chapter 14—for now it’s a good example to illustrate some of the parameters ASP.NET con-

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Chapter 9 Confi guration 193 Web.Confi g

While machine.confi g lays out the default setting for your machine (and ultimately for your applications), the default settings are generally targeted toward the most common use cases (rather than some special confi guration you may need to apply to your application) For ex-ample, sessionState is confi gured to be handled in process by default That’s fi ne when you’re

developing, but almost certainly is not appropriate for a commercial-grade application that is servicing many diverse clients

Because all your NET applications depend on machine.confi g to confi gure them, making changes to machine.confi g could potentially affect your other applications It’s a bad idea to update machine.confi g directly

Stand-alone NET applications depend on confi guration fi les modeled after the application name to confi gure themselves For example, an application named MyApp.EXE would have a

conﬁ guration ﬁ le named MyApp.EXE.confi g Of course, ASP.NET applications aren’t named in

that way Instead, the ASP.NET runtime expects conﬁ guration information to be declared in a

ﬁ le named web.confi g

To override the default settings, you simply need to include a ﬁ le named web.confi g in your

application’s virtual directory For example, the following code sets up the Web application to which it applies The conﬁ guration ﬁ le turns on Forms Authentication and tracing, for example

This way of managing conﬁ guration information works well Many of the normal defaults ply in most situations, and you sometimes need to tweak only a few items When you do, just drop a web.conﬁ g in your virtual directory and/or subdirectory

However, managing settings by littering your hard disk with web.confi g fi les can get a bit wieldy if lots of different parts of your application need separate confi gurations The ASP.NET confi guration schema includes a location element for specifying different settings for differ-

un-ent directories—but they can all go in a master conﬁ guration ﬁ le for your application

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For example, the following conﬁ guration section will remove the ability for the AppSubDir directory to process standard ASP.NET Web Services The remove instruction causes ASP.NET

to have amnesia about all ﬁ les with the extension asmx

lows all users into the main (virtual) directory while requiring users wanting access to the PagesRequiringAuth subdirectory to be authenticated

Managing Confi guration in ASP.NET 1.x

Confi guration within ASP.NET 1.x was done entirely by manually typing changes into a target web.confi g fi le For example, if you wanted your application to use SQLServer as a session state

database, you’d need to insert the correct verbiage into the application’s web.confi g fi le stroke by keystroke Unfortunately, there was no confi guration compiler to help ensure that the syntax was correct If you typed something wrong, you usually wouldn’t know about it until you ran the application, at which point ASP.NET would cough up a cryptic error message

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key-Chapter 9 Confi guration 195 Managing Confi guration in Later Versions of ASP.NET

ASP.NET 2.0 introduced some major improvements to the process of managing ASP.NET applications, and these improvements carry through to the current version of ASP.NET Although you can still type confi guration information into the web.confi g fi le manually, ASP.NET 2.0 and later versions provide some new confi guration utilities These tools include the Web Site Administration Tool (WSAT) available in Visual Studio and the ASP.NET confi gu-ration facilities available through IIS

Confi guring your application

In this exercise, you’ll change some application settings within an application’s confi guration and see how they’re refl ected within web.confi g

1 Begin by creating a new Web site named Confi gORama Make it a regular ASP.NET site

(not an empty one) It can be a ﬁ le system–based Web site

2 Run the ASP.NET Administration tool After Visual Studio generates the application,

se-lect the Web Site, ASP.NET Confi guration menu item This will bring up the ASP.NET Administration tool

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