My Silverlight experiences

Lambda expression in Silverlight 3 Databinding

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Mon, 28 Sep 2009 13:57:00 +0000

First of all let me thank to M. Orçun Topdağı for pointing out a useful cs file in the samples provided by Microsoft.You may get those samples in the below location.

[Install drive]:\Program Files\Microsoft Visual Studio 9.0\Samples

The file is Dynamic.cs which provides a bunch of functionality to work more with Lambda expressions.That sample was written for .Net 3.5 and I was afraid whether I can use that in my Application since I am working in Silverlight 3. But I was able to use the same classes for Silverlight and a sample which takes Lambda Expression from xaml and executes through converter is attached with this post.

How to specify a Lambda expression in XAML data-binding

I am using the ConverterParameter to get the lambda expression.The no of parameters to Lambda expression is limited because we can pass only one value to the converter.

<UserControl x:Class="SL_LambdaInConverter.MainPage"             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"             xmlns:local="clr-namespace:SL_LambdaInConverter">    <UserControl.Resources>        <local:LambdaConverter x:Key="lambda" />    </UserControl.Resources>    <Grid x:Name="LayoutRoot">        <TextBlock             Text="{Binding Converter={StaticResource lambda},ConverterParameter='dt=>dt.ToString()'}" />    </Grid></UserControl>

In the above sample I have set DateTime.Today as DataContext of the UserControl in the constructor.So it will take that value into the converter.Here is the converter code.

Option Strict OnImports System.Windows.DataImports System.Linq.ExpressionsImports System.Linq.Dynamic Public Class LambdaConverter    Implements IValueConverter    Dim _delegate As [Delegate]     Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert        If Me._delegate = Nothing Then            ConstructOperation(value, targetType, CType(parameter, String))        End If        Return Me._delegate.DynamicInvoke(value)    End Function     Public Function ConvertBack(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack        Throw New InvalidOperationException("Convert back operation is not supported")    End Function    Sub ConstructOperation(ByVal value As Object, ByVal t As Type, ByVal lambdaString As String)        Dim opi As Integer = lambdaString.IndexOf("=>")        If (opi < 0) Then Throw New Exception("No lambda operator =>")        Dim param As String = lambdaString.Substring(0, opi)        Dim body As String = lambdaString.Substring(opi + 2)         Dim p As ParameterExpression = Expression.Parameter(value.GetType(), param)        Dim lambda As LambdaExpression = DynamicExpression.ParseLambda(New ParameterExpression() {p}, t, body, value)        Me._delegate = lambda.Compile()    End SubEnd Class

Now you might wonder where is the System.Linq.Dynamic ? Here comes the importance of Dynamic.cs which I had mentioned at the beginning.You may find all those classes there.

Download and enjoy the sample here.

Silverlight 3 in Windows Mobile 7

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sun, 27 Sep 2009 08:10:00 +0000

Any developer who takes programming as a passion, would always like to see his application running in different plat forms.The code need to be same ,but runs every where.

.Net & Java did this by introducing an intermediate language to which every code compiles to and before running, it convert in to the native code.

When I entered into Silverlight it felt like I am writing code only for Browser.Prism has introduced a solution where we can use same code base for Silverlight as well as WPF.Now we have got much more support in extending our Silverlight code to different plat forms.

Yes.The support is in Mobiles. Microsoft has announced that their next Mobile operating system Windows Mobile 7 Will support Silverlight 3.They are planning to release Windows Mobile 7 in 2010.So plan your application accordingly,because it has to run in mobiles by next year.

Some links

http://www.silverlight.net/learn/mobile/
http://en.wikipedia.org/wiki/Windows_Mobile#Windows_Mobile_7

The need for ModuleBase class in Prism

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Tue, 22 Sep 2009 17:41:00 +0000

When I started a sample application in Prism, I came to some situations where I need ModuleManager and all.After a small google I came to know that if we specify some arguments in the constructor of Modules we could get lot of useful objects such as ModuleManager,RegionManager etc...We can hold them for future uses.

Instead of having properties in each module to hold these objects, it is always better to have an abstract base class which holds all these objects.Then I did a trial an error method to find out what are all the objects which we can get and it came around 4 objects.

IModuleManager
IRegionManager
IUnityContainer
IRegionViewRegistry

And the base class implementation is as follows.

using System;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Ink;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using Microsoft.Practices.Composite.Modularity;using Microsoft.Practices.Composite.Regions;using Microsoft.Practices.Unity; namespace Prism.Core{    public abstract class ModuleBase : IModule    {        IModuleManager _modulemanager;         public IModuleManager ModuleManager        {            get { return _modulemanager; }            set { _modulemanager = value; }        }        IRegionViewRegistry _regionViewRegistry;         public IRegionViewRegistry RegionViewRegistry        {            get { return _regionViewRegistry; }            set { _regionViewRegistry = value; }        }         IRegionManager _regionManager;        public IRegionManager RegionManager        {            get { return _regionManager; }            set { _regionManager = value; }        }         IUnityContainer _container;        public IUnityContainer Container        {            get { return _container; }            set { _container = value; }        }         public ModuleBase(IModuleManager moduleManager,             IRegionManager regionManager,            IUnityContainer container,             IRegionViewRegistry reg)        {            ModuleManager = moduleManager;            RegionManager = regionManager;            Container = container;            this.RegionViewRegistry = reg;        }         #region IModule Members         public abstract void Initialize();         #endregion    }}

The same thing is applicable in the case of Views too.

Is it DRM which we really need in Silverlight 4?

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sat, 19 Sep 2009 15:47:00 +0000

From some news sites and also from Microsoft's press pass I could know that there will be DRM support in Silverlight 4.DRM is a nice feature which I would like to be in Silverlight.

But I wonder why they are not telling about other features, which as a developer we are waiting for from the Silverlight 1.0 days itself.I came from the WPF environment so I will really look for the below features first instead of DRM.

Full implementation of Commands.Silverlight 3 doesn't have Button.Command property.Do we need to relay on interactions provided by blend 3?
FindAncestor for RelativeSource binding
InputBindings in UIElement.
Attached events.
Triggers or equivalent implementation in DataTemplates
Option to create custom mark-up extensions.
XPS support.
Printing.
More bindings in WCF such as TCP.

A huge wish list is here in Silverlight forum.Hope Microsoft will address our these small issues along with rocking new features.

Specify Modules in XAML

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 02 Sep 2009 16:40:00 +0000

When I first started PRISM my thought was how to specify the modules through a xaml file or an xml fille.The existing code is written as like something hard coded in the Bootstraper.cs.

protected override Microsoft.Practices.Composite.Modularity.IModuleCatalog GetModuleCatalog(){    var catalog = new ModuleCatalog();    catalog.AddModule(typeof(MarkModule));    catalog.AddModule(typeof(StudentsListModule));    return catalog;}

We can easily setup an xml file and create module objects using reflection.But I was sure, there will be an implementation of same somewhere in the framework.

After spending some time, I got a new way to implement my scenario.Why don't I have a new xaml file derived from ModuleCatalog and make the entries in xaml ? Yes that did the trick.

I added a new file which derives from ModuleCatelog and added my module entries.The xaml looks as below.

<modularity:ModuleCatalog     x:Class="Students.StudentsModuleCatalog"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    xmlns:modularity="clr-namespace:Microsoft.Practices.Composite.Modularity;assembly=Microsoft.Practices.Composite">     <modularity:ModuleInfo         ModuleName="StudentsListModule"        ModuleType="Students.StudentsListModule, Students, Version=1.0.0.0" />    <modularity:ModuleInfo         ModuleName="MarKModule"        ModuleType="Students.MarkModule, Students, Version=1.0.0.0" /> </modularity:ModuleCatalog>

Make sure that the code behind class should inherit from ModuleCatalog.

Now you can Rewrite the Bootstraper.GetModuleCatalog() as follows

protected override Microsoft.Practices.Composite.Modularity.IModuleCatalog GetModuleCatalog(){    return  new StudentsModuleCatalog();}

This makes the code more neat and we can easily add or remove modules.

Microsoft SSRS viewer in Silverlight

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Tue, 01 Sep 2009 04:58:00 +0000

Some time back we had a scenario of showing reports in Silverlight.Our first though was to create reports in ASP.Net and show that as popup window from Silverlight.But in the research we found out a great tool from Perpetuum softwares which renders the SSRS report inside Silverlight.

Main advantages were it capability to leverage features of Silverlight such as Vector graphics.We can zoom the report without losing it's clarity.

Online demo is available here .You need to install only Silverlight 3 in order view the report.

Basically it works by adding a component at the server side which makes the report compatible with their Silverlight viewer.Currently it supports SQL Server Reporting Services 2005 only.

Good work Perpetuum guys.Keep it up.

WCF service from Silverlight with Windows credentials

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sat, 15 Aug 2009 10:50:00 +0000

Last week this was our major research item.How to make Silverlight call a WCF service which needs Windows authentication?

In the ideal scenario ,if the user is already logged in with right windows credentials the system(here Silverlight) should not ask for user name and password again.Silverlight should recognize the user and pass those credentials automatically into the WCF service.We implemented the WCF service with Windows credentials and made the hosting ASP.Net application's authentication to Windows.But it was asking for the user name and password when we call the service from Silverlight.Really that dialog is ugly when comparing to the rich UI of Silverlight.The reason for this is under normal circumstances Silverlight can't access the windows credentials of user.

Avoiding the windows login dialog box

After a tough research, one of my colleague find out a solution to get rid of this windows authentication dialog.The solution is simple.Just add the name of website where the service is hosted, into trusted sites collection of browser.

But this solution has a draw back.The end user has to do this configuration in browser.We can't always expect them to do this setting.So the better way is to create a Silverlight authentication page which accept the windows credentials and call a login service to authenticate the user using the provided credentials.Once we get the user name and password we can easily authenticate the user by calling some native methods.

So if the user has setup the browser settings the Silverlight won't show the authentication dialog.Else show the Silverlight dialog and ask user to enter his windows login details again.

Again another question comes, whether the user will/can trust the website which asks for his windows credentials ? In that scenario forget the rich UI of Silverlight show them the native windows login dialog box...

Some references

Happy Independence day to all My Indians.

Some useful links to Prism

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sat, 08 Aug 2009 15:33:00 +0000

What is Prism

According to my understanding about prism ,it is nothing but a framework which implements a modularized environment for different application blocks or UI components. We can develop modules separately and plug into the different regions in UI.

Samples

Hope I can add my own articles when I the project starts.

Silverlight 3 released

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sat, 11 Jul 2009 03:24:00 +0000

Download tools from here and enjoy...

Added F# support in Silverlight

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 08 Jul 2009 04:57:00 +0000

According to wikipedia F# is a multi-paradigm programming language, targeting the .NET Framework, that encompasses functional programming as well as imperative object-oriented programming disciplines.
Now Silverlight also can take advantages of F# from F#'s May CTP onwards .

First you have to download and install the F# May CTP from here

Then install the templates from here

More details
http://blogs.msdn.com/lukeh/archive/2009/06/26/f-in-silverlight.aspx

Whether Silverlight 3 application is running online or not

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Thu, 21 May 2009 10:02:00 +0000

Just check the below mentioned property to know the network status of Silverlight application.We can do operations according to that.
Application.Current.ExecutionState

There are 5 possible states which are defined in System.Windows.ExecutionStates

// Summary:
//     Defines constants that indicate the state of an application that can run
//     offline.
public enum ExecutionStates
{
    // Summary:
    //     The application is running within its host Web page.
    RunningOnline = 0,
    //
    // Summary:
    //     The application is in the process of detaching from its host Web page.
    Detaching = 1,
    //
    // Summary:
    //     The application is running in offline mode, detached from its host Web page.
    Detached = 2,
    //
    // Summary:
    //     The application is running in offline mode, but a newer version of the application
    //     has been downloaded and will be used the next time the application is launched.
    DetachedUpdatesAvailable = 3,
    //
    // Summary:
    //     The application could not be detached from its host Web page.
    DetachFailed = 4,
}

RoutedEvents for Silverlight 3

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Tue, 19 May 2009 07:51:00 +0000

It is my pleasure to inform you that my colleague Andrew Whiddett at Identitymine has developed and released code for implementing Routed events in Silverlight 3.The code is available in Codeplex.See the below link.

http://sl3routedevents.codeplex.com/

Enjoy…

Silverlight 3 Beta Local Messaging among Silverlight islands

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Mon, 30 Mar 2009 12:36:00 +0000

If you have read my previous post about inter silverlight communication design you might seen how difficult it is to accomplish communication between 2 silverlight applications hosted in same page.But in Silverlight 3 Microsoft has introduced a new technique to do the communication.It is nothing but 2 classes.LocalMessageSender & LocalMessageReceiver.Now it is very easy to accomplish communication between islands of Silverlight contents.

Implementing Local messaging between silverlight applications
As like in other communication scenarios here also there should be a source and destination which sends and receives respectively.LocalMessageSender class sends a string message and LocalMessageReceiver receives the same.At the time of sending we should specify the name of the receiver.Also at the time of listening for message we should give the name of receiver.ie it denotes which messages it should capture based on the receiver name.
LocalMessageSender : The constructor of this class accepts the receiver name.To send the message we have to use the method SendAsync.The SendCompleted event is fired after completion of sending process.
LocalMessageReceiver : The constructor of this class also got a parameter to specify the receiver name.MessageReceived is the event which will fire when a message comes with the corresponding receiver name.After subscribing into this event the Listen Method need to be called in order to start listening.

Creating Visual Studio Solution structure
Here I have used 3 projects 2 Silverlight projects one is source and next is destination,and one asp.net application which hosts these 2 Silverlight applications.

Default.aspx

<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<div  style="height:100%;">
<asp:Silverlight ID="Silverlight1" runat="server" 
Source="~/ClientBin/LocalMessagingSource.xap" MinimumVersion="3.0.40307.0" 
Width="400" Height="100"/>
</div>
<div>
Your html contents goes here..
<h1>Heading</h1>
<h3>Sub heading</h3>
<p>contents</p>
</div>
<div  style="height:100%;">
<asp:Silverlight ID="Silverlight2" runat="server" 
Source="~/ClientBin/LocalMessagingDestination.xap" MinimumVersion="3.0.40307.0" 
Width="400" Height="100" />
</div>
</form>

MainPage.xaml in project LocalMessageSource

<UserControl x:Class="LocalMessagingSource.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Grid x:Name="LayoutRoot"
Background="AliceBlue"
Height="100"
Width="400">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock Grid.ColumnSpan="2"
HorizontalAlignment="Center">I am sender</TextBlock>
<TextBlock Grid.Row="1">Message</TextBlock>
<TextBox Grid.Row="1"
x:Name="txtMsg"
Grid.Column="1"
Text="" />
<Button Grid.Row="2"
Content="Send"
Click="Button_Click" />
<TextBlock x:Name="txtStatus"
Grid.Row="2"
Grid.Column="1" />
</Grid>
</UserControl>

MainPage.xaml.cs in project LocalMessageSource

private void Button_Click(object sender, RoutedEventArgs e)
{
LocalMessageSender msgSender = new LocalMessageSender("receiver");
msgSender.SendCompleted += new EventHandler<SendCompletedEventArgs>(msgSender_SendCompleted);
msgSender.SendAsync(txtMsg.Text); 
}

void msgSender_SendCompleted(object sender, SendCompletedEventArgs e)
{
txtStatus.Text = "Send";
}

MainPage.xaml.cs in project LocalMessageDestination

<UserControl x:Class="LocalMessagingDestination.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Width="400"
Height="100">
<Grid x:Name="LayoutRoot"
Background="LightGoldenrodYellow">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock Grid.ColumnSpan="2"
HorizontalAlignment="Center">I am receiver</TextBlock>
<TextBlock Text="Received messag"
Grid.Row="1" />
<TextBox x:Name="txtMessage"
Grid.Row="1"
Grid.Column="1" />
</Grid>
</UserControl>

MainPage.xaml.cs in project LocalMessageDestination

public MainPage()
{
InitializeComponent();
LocalMessageReceiver receiver = new LocalMessageReceiver("receiver");

receiver.MessageReceived += new EventHandler<MessageReceivedEventArgs>(receiver_MessageReceived);
receiver.Listen();
}

void receiver_MessageReceived(object sender, MessageReceivedEventArgs e)
{
txtMessage.Text = e.Message;
}

Sample can be downloaded from here.

There are so many options with this messaging APIs such as domain blocking etc.You can send to some specific domains by using these options.More details later…

NB:This post is written using Silverlight 3 Beta.Things may change in Actual release.

Silverlight 3 Beta Deep linking using Navigation application

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Sat, 28 Mar 2009 13:14:00 +0000

The main disadvantage of earlier RIA technologies like Flash and Silverlight 2 was the absence of Deep linking.ie we can’t maintain a link to a specific screen or page in the RIA application.We can see just same URL even we change screens or pages in RIA application.Hence we can’t give a specific url to somebody or book mark that screen by url.Each time when the RIA application loads we have to navigate again to reach a specific page.That is very much time consuming.
Eg: If we want to have a profile page in our application how will we handle that in ASP.Net ? it’s simply addressed by using a page called profile.aspx with querystring ?id=10
This was not possible in Silverlight until the release of Silverlight 3 and it’s Navigation application support.With the introduction of navigation support we can maintain constant links to specific screens in the Silverlight RIA application.Hence we can distribute that link and bookmark that Silverlight page.

Creating a deep linked address book application using Silverlight
Since the main aim is to demonstrate deep linking ,I am using a simple Person class with properties Id ,Name and Address.The data storage is an Xml file.Here is the Person class.

public class Person
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public string Address { get; set; }
    }

Designing Data access
The PersonDataContext class provides the required Data.AllPersons and GetPersonById are the members which returns collection of all persons and Person by id respectively.

public class PersonDataContext
{
    XDocument _doc;
    private XDocument XmlDoc
    {
        get
        {
            if (_doc == null)
            {
                 _doc = XDocument.Load("Persons.xml");
            }
            return _doc;
        }
    }
    public IEnumerable<Person> AllPersons
    {
        get
        {
            return from li in XmlDoc.Root.Elements()
                   select new Person()
                   {
                       ID = Convert.ToInt32(li.Attribute("Id").Value),
                       Name = li.Attribute("Name").Value,
                       Address = li.Attribute("Address").Value
                   };
        }
    }
    public Person GetPersonById(int id)
    {
        XElement ele= XmlDoc.Root.Elements().First(s => s.Attribute("Id").Value == id.ToString());
        Person person=null;
        if(ele !=null)
        {
            person = new Person()
            {
                ID = Convert.ToInt32(ele.Attribute("Id").Value),
                Name = ele.Attribute("Name").Value,
                Address = ele.Attribute("Address").Value
            };
        }
        return person;
    }
}

Building User Interface

We are using a ListBox to display the list of persons in the HomePage.xaml.The ItemTemplate of the ListBox contains a hyperlink button and its NavigateUri is binded to Person object using a converter named Person2UriConverter.We are using a converter because the NavigateUri expects a object of type Uri.One more thing is that we don’t have path to details page in Person class.So we used a converter which combines the page url with the newly created name value pair.

HomePage.xaml

<navigation:Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"
                 xmlns:local="clr-namespace:AddressBook"
                 x:Class="SilverlightApplication1.HomePage"
                 xmlns:conv="clr-namespace:AddressBoook.Converters"
                 Title="HomePage Page">
    <navigation:Page.Resources>
        <conv:Person2UriConverter x:Key="p2uri" />
        <local:PersonDataContext x:Key="PersonDataContextDataSource" />
        <DataTemplate x:Key="personDT">
            <StackPanel>
                <HyperlinkButton Content="{Binding Name}" NavigateUri="{Binding Converter={StaticResource p2uri}}"></HyperlinkButton>
            </StackPanel>
        </DataTemplate>
    </navigation:Page.Resources>
    <Grid x:Name="LayoutRoot" Background="White" >
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <ListBox DataContext="{Binding Source={StaticResource PersonDataContextDataSource}}"
                 ItemsSource="{Binding Mode=OneWay, Path=AllPersons}"
                 ItemTemplate="{StaticResource personDT}" Grid.Row="1" />
        <TextBlock Text="Home" Style="{StaticResource HeaderTextStyle}"/>
    </Grid>
</navigation:Page>

Person2UriConverter.cs

public class Person2UriConverter:IValueConverter
    {
        #region IValueConverter Members
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            Person person = value as Person;
            string localpath = System.Windows.Browser.HtmlPage.Document.DocumentUri.LocalPath;
            return new Uri(localpath+"#/Views/Person.xaml?id="+person.ID,UriKind.RelativeOrAbsolute);
        }
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
        #endregion
    }

Now we made the display of listbox with all persons.Now when run and click on the person link we can see the new url as http://localhost:61838/SilverlightApplication1TestPage.aspx#/Views/Person.xaml?id=1.It won’t display anything since there is no Person.xaml.Create the Person.xaml page which is going to be the detail view.

Creating detail page Person.xaml

Here the idea is to get the query string parameter id and load the Person class.This Person class is set as DataContext of the newly created a Page called Person.xaml where it is going to display the details.DataContext is setting on the overriden method OnNavigateTo.

Person.xaml.cs

// Executes when the user navigates to this page.
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            int personId = Convert.ToInt32(this.NavigationContext.QueryString["id"]);
            this.DataContext = new PersonDataContext().GetPersonById(personId);
        }

Person.xaml

<navigation:Page x:Class="SilverlightApplication1.Views.Person" 
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"
           Title="Person Page">
    <Grid x:Name="LayoutRoot"
          Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <TextBlock Text="ID" />
        <TextBox Grid.Column="1"
                 Text="{Binding ID}" />
        <TextBlock Grid.Row="1"
                   Text="Name" />
        <TextBox Grid.Row="1"
                 Grid.Column="1"
                 Text="{Binding Name}" />
        <TextBlock Grid.Row="2"
                   Text="Address" />
        <TextBox Grid.Row="2"
                 Grid.Column="2"
                 Text="{Binding Address}" />
    </Grid>
</navigation:Page>

Now when we click on the Person link we will get the detail page Person.XAML.Now you can distribute the URL to your friends and you can yourself use that as bookmark in your browser.

Sample can be downloaded from here.

Silverlight 3 Beta Navigation Application support

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Fri, 27 Mar 2009 04:29:00 +0000

This is another new feature added in Silverlight 3 which is based on WPF paging concept.Navigation or Paging support gives us flexibility to design our application as page wise.It is more likely to ASP.Net page concept than windows programming.There will be a container which contains pages and we can switch among pages by user actions as well as by programmatically.The main advantage of this is we can identify each Silverlight page by it’s url.We will discuss about this deep linking feature in a new post.

Creating Silverlight navigation application / paging enabled Application.

The Silverlight 3 tools for visual studio 2008 brings a new project template for Navigation application.Select that project template and create.The project template itself contains 3 sample Pages AboutPage.xaml,ErrorWindow.xaml and HomePage.xaml in the Views folder.

These pages are hosted in MainPage.xaml using a control called Frame coming from the assembly System.Windows.Controls.Navigation.The Source property of Frame denotes the current page which is displaying in Frame.Change the Source property if you need to change the current page.
When we run the application we can see a good style for the controls in it.That is not magic of paging but the effect of styles and templates present in App.xaml :-)

Switching among pages

There are 2 methods to switch current page.

this.Frame.Navigate(new Uri(“goToPageURI”, UriKind.Relative));
(Or)
this.Frame.Source = new Uri(“goToPageURI”, UriKind.Relative);

Controlling navigation / paging behavior

There are so many properties and methods available in Page and Frame classes to control the navigation behavior such as Frame.CanGoBack,Frame.CanGoForward,Frame.StopLoading() etc….Main requirement will be getting the query string parameters in the page in order to load something or show something.It is available in NavigationContext.QueryString property.

Note that the query string contains the name value pairs which comes after the ‘;’ symbol.You can’t get the path (Eg:#/Views/HomePage.xaml)to page there.

NB :The above post is written based on Silverlight 3 Beta build.Things may change in the actual release.

Silverlight 3 Beta Merged Resource Dictionaries

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 25 Mar 2009 17:16:00 +0000

This helps us to link resource dictionaries.That means we can split up our resource dictionaries into small files and link them together to act like a single resource dictionary.

Earlier when we develop a Silverlight custom control library we have to keep all the control styles and templates in a single resource dictionary file called generic.xaml.That is very much confusing and makes the generic.xaml very huge and complex.We can’t maintain that resource dictionary easily.The main advantage of Merged resource dictionary comes here.We can split up the styles and templates of each individual Silverlight control into separate resource dictionary files and maintain easily.

Also when we are in styling or templating controls in a complex user control we can split up similar styles into different resource dictionaries.Normally its very useful to separate Brushes and colors from the styles.

Creating Resource Dictionary

If you are using Visual studio there is no direct support to add a ResourceDictionary.So add a new UserControl and do the following.

Delete the xaml.cs file
Remove the x:Class attribute from UserControl’s xaml declaration.
Remove the Width and Height properties
Remove the default Grid control.
Change Build action to Resource.
Rename the UserControl XAML tag to ResourceDictionary.

Now the XAMl will look as follows

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
</ResourceDictionary>

To create a new ResourceDictionary using Blend 3 ,go to resources tab.Click on the ‘+’ located at top right to show the creation dialog.Give the name and press ‘OK’.I will be writing another post in detail which describes creation and manipulation of ResourceDictionaries using blend.

Adding resources

Adding xaml elements into ResourceDictionary is same as before.We can add any xaml element including Button,Grid,Brush,Color,Templates,Styles etc…A typical Colors.xaml resource dictionary is shown below

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
    <Color x:Key="bgcolor">Red</Color>
</ResourceDictionary>

Merging resource dictionaries

ResourceDictionary now got a new property called MergedDictionaries.This is a collection of ResourceDictionaries.We can add any number of ResourceDictionaries into this.Also we can merge a ResourceDictionary into another ResourceDictionary.Below is a Brushes.xaml which uses the Colors.xaml as a merged resource dictionary.

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Colors.xaml" />
    </ResourceDictionary.MergedDictionaries>
    <SolidColorBrush x:Key="background" Color="{StaticResource bgcolor}"/>
</ResourceDictionary>

Now we got brushes.xaml.This can be merged again with UserControl.xaml in order to use the brushes.

<UserControl x:Class="CustomEffects.MainPage"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             Width="400" Height="300">
    <UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Brushes.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot">
        <Button Grid.Row="1"
                Background="{StaticResource background}"
                Content="Click to change"></Button>
    </Grid>
</UserControl>

Sample can be downloaded from here.

New features in Expression Blend 3 Part 1

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 25 Mar 2009 04:22:00 +0000

Blend 3 has got so many new features.But here I am going to tell some small easy to explain nice features.

Importing from Adobe Illustrator to Blend(*.ai files)
Importing from Adobe Photoshop to Blend (*.psd files)
Pinning support for Toolbox Windows like VisualStudio
FontManager
Auto-naming of interactive elements.
IntelliSense in XAML as well as in CS.
Annotation support.

Importing Adode files : These are just facilities to import vector based .ai files from the Adobe illustrator and psd files from PhotoShop.

Pinning support for ToolBox Windows : Now the toolboxes are same as of Visual studio toolboxes.If we don’t want some toolboxes we can pin them to the respective sides of the window.Pin button is placed same like in the Visual studio(at top right).

Font Manager : Font manager allows us to import fonts and add to our solution.Later we can pack these fonts with our application.

Tools->FontManager

Auto naming interactive elements : This gives name to the interactive elements like Button,Textbox etc.Note that this won’t name the Grid,StackPanel etc..

Tools->Name Interactive Elements

IntelliSense in XAML as well as in CS : It has got IntelliSense support for both XAML and C-Sharp.

Annotation support : Now we can add annotations over the design area of Expression Blend.They are very much useful in describing nature and purpose of visual elements.From my first experiments it seems ,WPF only supports this feature.

Tools->Create Annotation

There are some more new features such as Sample data which help us to show sample data in design time.That will be discussed soon…

Silverlight 3 Beta Offline or Out of Browser applications

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Tue, 24 Mar 2009 11:21:00 +0000

Now Microsoft added support for Silverlight applications to run out of browser.Earlier it was accomplished by a tool called Desklighter released by Identitymine.

Details on how to make a Silverlight 3 application offline is available here by Pete Brown.

Portability of offline Silverlight applications.

This post describes how can we make the Silverlight applications portable.ie how to copy offline Silverlight application from one system to another.

Normally when we select the Install button on the silverlight context menu the system copies the required files (mainly .xap)into a cache folder locatable at

[Drive]:\Users\[username]\AppData\LocalLow\Microsoft\Silverlight\Offline

The folder name will be localhost.<serial no of offline app in the system> provided the Silverlight application which you saved is running in the localhost.

For eg if you are creating your first offline application the folder name will be localhost.0.

Once you locate this offline folder you can just copy that folder to the new machine.To run the application you need to copy the Shortcut file also which was created in the desktop or in the start menu.In case you don’t have the short cut file you may run by giving the following command in console.

[Install drive]:\Program Files\Microsoft Silverlight\3.0.40307.0\sllauncher.exe" localhost.0

To run another offline application just change the number (here 0) at the end.

NB: This post is written based on Silverlight 3 Beta.Things may change in actual release.

Silverlight 3 Beta Pixel Shader Effects

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Mon, 23 Mar 2009 04:03:00 +0000

This is another nice feature included in Silverlight 3.Pixel shaders are programs which operate at pixel level.ie all pixel values(value of A,R,G,B) are passed through the associated pixel shaders before displaying in the screen.Then the pixel shaders will do some calculations and change the pixel value.
For example if we have applied a pixel shader called “Negative” to a StackPanel,then all pixels in the area of that StackPanel will go through Negative pixel shader and it Negate the pixel values by decrementing from 255(255-A,255-R,255-G,255-B).
This is the basic idea of pixel shaders and the Silverlight 3 itself contains 2 Pixel shader effects as of now.They are DropShadow and Blur.

Applying pixel shader Effect

Now the UIElement class in the Silverlight has got a new dependency property called Effect which is the entry point to the pixel shaders.We can directly apply the Effect to this property.Since all the controls and visual elements are inherited from UIElement,they also have the pixel shader support.
Applying DropShadow pixel shader effect through XAML to a Button

<Button HorizontalAlignment="Center" VerticalAlignment="Center" Content="Joy's Button">            <Button.Effect>                <DropShadowEffect Color="Black"                                  ShadowDepth="5" />            </Button.Effect></Button>

C# to Apply DropShadowEffect

private void Button_Click(object sender, RoutedEventArgs e){    btn.Effect = new DropShadowEffect() { Color=Colors.Black,ShadowDepth=5};}

Grouping pixel shader effects

The Silverlight 3 currently doesn’t support grouping of Effects.If we want to apply Blur effect and DropShadow effect to a Button we have to go for a workaround.

Wrap the control using a Border.
Apply the new effect to the border.

<Border>            <Button HorizontalAlignment="Center"                    VerticalAlignment="Center"                    Content="Joy's Button">                <Button.Effect>                    <DropShadowEffect Color="Black"                                      ShadowDepth="5" />                </Button.Effect>            </Button>            <Border.Effect>                <BlurEffect Radius="5" />            </Border.Effect></Border>

Blur effect has been applied to the Border in order to get more than one effect on the Button.Writing custom pixel shader effects will be discussed later.

Silverlight 3 Beta ElementToElement Binding

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Fri, 20 Mar 2009 07:40:00 +0000

Finally it is released with developer license and available for download here.

It has got so many features.Among them the Element to Element Binding got my attention first.That is the feature which I was waiting from the beginning as I came from WPF background.

What is Element to Element Binding

It is nothing but binding one element’s property to other element’s property.If the properties are of different type we need to employee a converter.

        1: <StackPanel>
       2:             <Slider x:Name="sldr" />
       3:             <TextBox Text="{Binding ElementName=sldr,Path=Value,Mode=TwoWay}"  />
       4:</StackPanel>

Here the Slider is the source and the TextBox is the destination.Whenever the Slider changes the TextBox will get slider’s value and vice versa.
If there is no mode specification the binding will be one way hence the TextBox will get updated as per Slider.But slider will not update as per TextBox.

Moonlight for Linux released

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Thu, 12 Feb 2009 05:08:00 +0000

Moonlight is an open source Silverlight implementation in Linux.Now it support the features of Silverlight 1.0.It is available in 32 bits as well as 64 bits.
http://www.mono-project.com/Moonlight
Download it from the below link.Its just 0.9MB
http://www.go-mono.com/moonlight/

Using Silverlight as View in ASP.Net MVC

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 11 Feb 2009 04:55:00 +0000

Tim explains how we can use Silverlight as View in an ASP.Net MVC application.
http://timheuer.com/blog/archive/2009/02/09/silverlight-as-a-view-in-aspnet-mvc.aspx

Online C# Compiler in Silverlight

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Fri, 06 Feb 2009 04:52:00 +0000

Great thought.
It helps to learn C# without installing the C# compiler in your machine.
http://nokola.com/TryCSharp/

Working with JSON using DataContractJsonSerializer class

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Wed, 21 Jan 2009 12:58:00 +0000

This class DataContractJsonSerializer is available in the assembly System.ServiceModel.Web.dll.Add a reference to this in your project.
This is the data class which we are going to serialize ie converting from object to JSON format.

public class Employee   
{       
    public string Name { get; set; }       
    public string Designation { get; set; }   
}

private void btn_Click(object sender, RoutedEventArgs e)        
{            
    Employee emp=new Employee(){ Name="Joy",Designation="Sr soft engg"};            
    DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Employee));            
    MemoryStream stream=new MemoryStream();            
    StreamReader sr = new StreamReader(stream);            
    ser.WriteObject(stream, emp);            
    sr.BaseStream.Position = 0;            
    string s= sr.ReadToEnd();            
    MessageBox.Show(s);                    
}

Deserializing ie converting from JSON to object can be done using the method ser.ReadObject()

Download source code of Silverlight 2 runtime and controls

joymon@gmail.com (Joymon | ജോയ് മോന്‍ | जोय मोन | ஜோய் மோன்) — Fri, 09 Jan 2009 08:30:00 +0000

http://www.microsoft.com/downloads/details.aspx?FamilyID=EB83ED4C-AC85-4DE9-8395-285628EE2254&displaylang=en

Reduce your time on .net reflector...

Happy Coding..