Saturday, March 27, 2010

.NET Mobile Introduction

Background
Cell phones (mobile phones) have become part of our life style.

Today, mobile devices can connect to the Internet, and execute web applications.

Mobile applications can now be developed to deliver any types of data, to any user, any place in the world!

Different mobile devices support different programming languages. Some support WAP and WML, some support HTML or a limited version of HTML, and some support both or a different language.

To support all types of mobile devices, developers must create one different application for each language.

With .NET Mobile, Microsoft has introduced a new platform for developing mobile applications.

This tutorial is about how to develop applications with an extension to the .NET Framework, called the Microsoft Mobile Internet Toolkit (MMIT) or simply .NET Mobile.

What You Should Already Know

Before you continue you should have a basic understanding of the following:

* HTML / XHTML
* XML namespaces
* ASP .NET

.NET Mobile

.NET Mobile is an extension to Microsoft ASP.NET and the Microsoft's .NET Framework.

.NET Mobile is a set of server-side Forms Controls to build applications for wireless mobile devices.

These controls produce different output for different devices by generating WML, HTML, or compact HTML.

How Does It Work?

The following table shows how the .NET Mobile works:

Mobile Devices
The Internet
Internet Information Services - IIS
The .NET Framework
ASP.NET
.NET Mobile

* A web client requests a web page
* The request travels the Internet
* The request is received by IIS
* The request is handled by the .NET framework
* The requested page is compiled by ASP.NET
* .NET Mobile handles any mobile device requirements
* The page is returned to the client

Software Requirements
To develop mobile applications with .NET Mobile, you must have the following components:

1. Windows 2000 Professional/Server with IIS 5
2. All Windows 2000 service packs
3. The ASP.NET framework
4. Microsoft Mobile Internet Toolkit (MMIT)
5. Internet Explorer 5.5 or later
6. A WAP simulator

You will need Windows 2000 to develop .NET applications (IIS 5 (Internet Information Services) is a part of Windows 2000).

How To Start

Developing a mobile web application with ASP.NET is very easy:

1. Create an ASP.NET page
2. Include System.Mobile.UI
3. Add Mobile Controls to the page


.NET Mobile Example


The Mobile ASP.NET Page

Mobile Controls are the main building blocks of mobile applications.

Mobile Controls are similar to Web Controls in ASP.NET.

The following ASP.NET page displays "Hello W3Schools" as a WML card in a WML enabled cell phone:
<%@ Page
Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register
TagPrefix="mob"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>


Hello W3Schools


The Page directive tells ASP to use (inherit) mobile page handling instead of regular page handling (like the one used for traditional browsers).
The Register directive defines the prefix that will be used for mobile controls. We have used "mob", but you can use any prefix you like.

The element tells the server to create a mobile form control.

The element tells the server to create a mobile label control with the text "Hello W3Schools".

When the ASP .NET page executes, it will produce the following output to a WAP enabled mobile phone:

'-//WAPFORUM//DTD WML 1.1//EN'
'http://www.wapforum.org/DTD/wml_1.1.xml'>



Hello W3Schools





and this output will be produced for a Pocket PC:



action="example.aspx">
Hello W3Schools






Conclusion

.NET Mobile will generate WML code for WAP enabled cell phones and HTML code for devices like the Pocket PC.

By detecting the browser, .NET Mobile will output correct content, providing developers with a powerful tool to develop single applications that will serve many different mobile devices.

.NET Mobile Emulators

Mobile applications can be tested and viewed with different emulators.
Using your Browser

Since mobile web pages detect your browser, you can test your mobile applications with a standard browser.

When a mobile web page detects a web browser it will produce HTML output.
Openwave Simulators

The Openwave mobile browser is the most common browser used in Internet-enabled cellphones.

An emulator can be downloaded from http://www.openwave.com
The Nokia Mobile Internet Toolkit

This toolkit contains emulators for most of the different Nokia devices.

This toolkit can be downloaded from http://forum.nokia.com
Windows Mobile Development Platform

Here you'll find answers to basic questions regarding the Windows Mobile development platform, along with different downloads:

http://msdn.microsoft.com/en-us/windowsmobile/bb250560.aspx

.NET Mobile Forms

.NET Mobile Forms are specialized web forms designed to work on different mobile devices.
Mobile Pages

A mobile page is much the same as an ordinary .NET web page. It is a text file with an aspx extension, and it can contain a variety of web controls.

The difference is the page directive that identifies the page as a mobile page, and the controls used on the page, which are mobile controls.

The mobile controls can be programmed device-independently, and the page will produce an output that suits the device that access it.
Mobile Forms

Each mobile page must have at least one mobile form, and each mobile form can have a number of mobile controls.

Note that mobile pages can have multiple mobile forms. This is due to the nature of mobile devices. Mobile devices have small screens and it is very normal to navigate between screens with a simple link.
Automatic Paging

.NET Mobile supports automatic paging for different mobile devices.

The paging is handled differently for each control. For example when paging takes place the controls included in a panel control will stay together.
Displaying Text

This mobile page uses a TextView control to display a large amount of text:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>



This is a very long text to demonstrate
how text can be displayed over several screens.
This is a very long text to demonstrate
how text can be displayed over several screens.
This is a very long text to demonstrate
how text can be displayed over several screens.
This is a very long text to demonstrate
how text can be displayed over several screens.



When this page is displayed on a mobile device, the navigation and display functions of the page will be compiled differently for different devices with different display characteristics.

When the text is displayed on a pocket PC with a small display, the user will be able to scroll the text with a scroll bar, but on a cell phone the text will be displayed over several screens with proper navigation tools added.

Note that all mobile controls must have the runat attribute set to "server", in order to secure proper rendering of the page for different devices.
Single Forms

This mobile page has one form:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>


Hello W3Schools



Multiple Forms

This mobile page has two forms:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>


Hello W3Schools

2




Hello Again

1



.NET Mobile Events

Mobile Controls exposes device independent programmable events.
Programming Events

Mobile controls have an object model with programmable properties, methods and events.

For a complete overview please refer to the reference section.
Submitting Text

This page has two forms:
<%@ Page
Inherits="System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>




Age?








When a page has two forms, the first form is always opened by default.

The first form has a label with the text "Age?", an input box to input the age, and a submit button.

The second page is activated by the submit button on the first page, and displays a response.

When the application runs on a mobile device, the two pages will display like this:

Form 1
Age?




Form 2
You are 11 years old








.NET Mobile Input

Input Controls are used to collect input from the mobile user.
Input Controls

There is a number of mobile controls that support user input.

The most common input control is perhaps the TextBox control, which was demonstrated in the previous chapter. The TextBox control is perfect for simple user input like names, numbers, identifications and keywords.

For larger amount of input a TextView control is a better choice. The TextView control allows long multi-line input like the one you need for SMS or other messages.
Numeric Input

The numeric attribute of the textbox control can be set to true or false to specify whether the textbox should accept only numeric input.

Note: This behavior will normally work on cell phones by changing the input mode from letters to numbers. For HTML browsers however, this behavior is normally not supported.
Password Input

The password attribute of the textbox control can be set to true or false to specify whether the textbox should be treated as a password field.

A password field will hide the input by displaying * (stars) instead of ordinary text.
List Controls

TextBox and TextView controls are well suited for entering input, but sometimes you want the user to select from a list of predefined values.

The SelectionList Control supports drop down lists, check boxes and radio buttons. This topic is covered in another chapter.

The List Control supports selection from menus and lists. The List Control is covered in another chapter.

User Interface Controls

User Interface Controls are controls which display the user interface:

Name Function
Command Performs an action
Form Defines a container for mobile controls
Image Defines an image
Label Defines a text
Link Defines a hyperlink
List Defines a list
MobilePage Defines a container for mobile controls
ObjectList Defines a list of data objects
Panel Defines a container for other controls
SelectionList Defines a list to select from
StyleSheet Defines styles to be applied to other controls
TextBox Defines a single line input box
TextView Defines a multi-line input box

For a full control reference, including properties methods, events, and more examples, please look at the "Mobile Reference" page.

.NET Mobile Input Validation

Validation Controls are used to validate the data entered by a user.
Validation Controls

Validation controls are used to validate the data entered by a user.

Validation controls allow you to validate an input control (like a TextBox), and display a message when validation fails.

Each validation control performs a specific type of validation (like validating against a specific value or a range of values).

By default, page validation is performed when a command control is clicked. You can prevent validation when a control is clicked by setting the CausesValidation property to false.
Validating Input

This page has two forms:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>





ControlToValidate="age"
Type="Integer"
ValueToCompare="18"
Operator="GreaterThanEqual">
You must be at least 18


Age?


Submit







The first form has a label with the text "Age?", an input box to input the age, and a submit button.

The second page is activated by the submit button on the first page, and displays a response.

If the input validates as error, an error message is displayed.

When the application runs on a mobile device, the two pages will display like this:

Form 1
Age?




Form 2
You are 21 years old







The ValidationSummary Control

The previous example used a CompareValidator control to validate an input field. The field to validate was defined by the attribute ContolToValidate.

You can also use a ValidationSummary control with the attribute FormToValidate, to validate all the input of a form.

This way you can display a summary of errors instead of one error at the time.
Validation Controls Reference
Name Function
CompareValidator Compares two values
CustomValidator Provides custom validation
RangeValidator Validates a range
RegularExpressionValidator Validates an expression
RequiredFieldValidator Validates required data
ValidationSummary Displays a validation summary

.NET Mobile Lists

The Mobile List Control supports different input and display properties.
Selecting from a List

This page has two forms:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>




OnItemCommand="Show_Price">










The first form has a list of cars.

The second page displays a price. This page is activated when a car is selected on the first page.

When the application runs on a mobile device the two pages will display like this:

Form 1
Volvo
BMW
Audi


Form 2
Volvo=$30,000







.NET Mobile Selections

The SelectionList Control supports drop down lists, check boxes and radio buttons.
The SelectionList

This mobile page uses a SelectionList to let the user select a car:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>








OnClick="Car_Click" Text="Submit" />






When this page is displayed on a mobile device, the navigation and display functions of the page will be compiled differently for different devices with different display characteristics.

Fore some devices, like a handheld PC, it might display a dropdown list to choose from. For a cell phone it might display a list of options to select from.

.NET Mobile Images

.NET Mobile displays different types of images for different types of devices.
The Image Control

Different mobile devices have different display capabilities.

The Image Control allows the developer to specify different types of images for different types of devices.
Image Types

Some mobile devices will display GIF images. Other mobile devices will display BMP images or WBMP images. The Image Control allows you to specify different images for each preferred image type.

This mobile page displays an image:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>











When this page is displayed on pocket PC, a GIF image will be displayed. On a cell phone a WBMP image or a BMP image will be displayed, according to the characteristics of the cell phone.

.NET Mobile Utilities

Utility controls support complicated user interfaces with minimum of code.
The AdRotator Control

This mobile page displays different advertisements:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>


AdvertisementFile="advertisements.xml">



This is the ad file called "advertisements.xml":

&br version="1.0" ?>



image1.gif
image1.bmp
image1.wbmp
http://www.1.com
Visit 1



image2.gif
image2.bmp
image2.wbmp
http://www.2.com
Visit 2



image3.gif
image3.bmp
image3.wbmp
http://www.3.com
Visit 3




The Calendar Control

This mobile page displays a calendar:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>




OnSelectionChanged="CalChanged" runat="server" />






In this example a calendar is displayed in the first form. When the user select a date from the calendar, the selected date is displayed in a new form.
The PhoneCall Control

This mobile page will display the text "Tove's number" and dial the number (555) 555-5555 when the user selects the text:
<%@ Page
Inherits=
"System.Web.UI.MobileControls.MobilePage"%>
<%@ Register
TagPrefix="Mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>



PhoneNumber="(555) 555-5555"
Text="Tove's number"
AlternateFormat="{0}" />



The attribute "AlternateFormat" has the value "{0}". This displays the text from the attribute "Text".

If you use the value "{1}" it will display the text from the attribute "PhoneNumber".

You can also use a construct like this: AlternateFormat="{0} is {1}". This will display the text "Tove's number is (555) 555-5555".

Utility Controls
Name Function
AdRotator Displays advertisements
Calendar Displays a calendar
PhoneCall Calls a telephone number

For a full control reference, including properties methods, events, and more examples, please refer to the "Mobile Reference" page.

ASP.NET Mobile Controls Reference

Main Mobile Objects

.NET Mobile supports three main objects:

* The Mobile Page
* The Mobile Form
* The Mobile Panel

The Mobile Page is the container for the application.

Each Mobile Page can have one or more Mobile Forms.

Each Mobile Form can have zero or more Mobile Panels.

Mobile Forms and Mobile Panels are used to group Mobile Controls.
Mobile Controls

Mobile Controls are grouped into:

* User interface controls
* Validation controls
* Utility controls

UI Controls

UI controls are controls that displays the user interface:

Name Function
Command Performs an action
Form Defines a container for mobile controls
Image Defines an image
Label Defines a text
Link Defines a hyperlink
List Defines a list
MobilePage Defines a base class for all mobile pages
ObjectList Defines a list of data objects
Panel Defines a container for other controls
SelectionList Defines a list to select from
StyleSheet Defines styles to apply to other controls
TextBox Defines a single line input box
TextView Defines a multi-line input box

Validation Controls

Validation controls are used to validate the data entered by a user:
Name Function
CompareValidator Compares the value of one input control to the value of another input control or to a fixed value
CustomValidator Allows you to write a method to handle the validation of the value entered
RangeValidator Checks that the user enters a value that falls between two values
RegularExpressionValidator Ensures that the value of an input control matches a specified pattern
RequiredFieldValidator Makes an input control a required field
ValidationSummary Displays a report of all validation errors occurred in a page

Utility Controls

Utility controls support complicated user interfaces with minimum of code:
Name Function
AdRotator Displays advertisements
Calendar Displays a calendar
PhoneCall Calls a telephone number


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