Light Up the Web with Silverlight by Jacek Ciereszko

Isolated Storage Memory in Silverlight 2.0 Beta 2

Jacek Ciereszko — Sun, 15 Jun 2008 20:56:15 GMT

In this article, I would like to describe Isolated Storage Memory in Silverlight 2.0. Isolated storage is a place on local disk, where applications have all access privileges to store their data. Default settings, give applications 1 MB space but this can be changed by administrator.

This memory space let application read files and create new, without special permissions. I used this feature, for example to store user settings (user name, application skins, etc.), local high scores for Silverlight game or as a flag in survey, to remember if user already voted today. It’s very useful and sooner or later you will use it ;)

Let’s dance

As an example, we will create simple demo, which will remember our name and will show it every time when we turn on application on our computer.

First, let's add two controls to "enter name":
<TextBox Height="32" x:Name="EnterName" Width="192" Text="Enter your name here" TextWrapping="Wrap"/>
<Button Height="28" x:Name="SubmitButton" Width="106" Foreground="#FF313131" Content="Submit" Click="SubmitButton_Click">

and one control to "show entered name"
<TextBlock Height="91" x:Name="NameTextBlock" Width="284" TextWrapping="Wrap" >
<Run x:Name="UserName" FontFamily="Comic Sans MS" FontSize="36" FontWeight="Bold" Text="" />
</TextBlock>

Then, add methods to write and read name from file in Isolated Storage. These methods are invoked from SubmitButton_Click event and from Page.Loaded event. To do this, we need IsolatedStorageFile object

IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication();

which we will use to check if file with user name exist

if (!isf.FileExists(“our_file.txt”))

and to create FileStream object

IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(“our_file.txt”, FileMode.Open, isf);

Now, all we have to do is use for example StreamReader and make all operation like with simple text file on desktop application.

StreamReader sr = new StreamReader(isfs);
userName = sr.ReadToEnd();
sr.Close();

To save user's name in Isolated Storage, open file with different FileMode, for example

IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(“our_file.txt”, FileMode.Create, isf);

and instead of StreamReader, use StreamWriter

StreamWriter sw = new StreamWriter(isfs);

All other parts of code for save method are similar to read parts.

Completed code for save method:
private void SaveUserName(string name)
{
     IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication();
     IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(FILE_NAME, FileMode.Create, isf);
     StreamWriter sw = new StreamWriter(isfs);
     try
     {
            sw.WriteLine(String.Format("{0}", name));
     }
     catch (Exception ee) { }
     finally
     {
            sw.Close();
            isfs.Close();
            isfs.Dispose();
            isf.Dispose();
            sw.Dispose();
      }
}

Completed code for read method:
private string ReadNameIfExist()
{
      string userName = String.Empty;
      IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication();
      if (!isf.FileExists(FILE_NAME))
            return userName;

      IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(FILE_NAME, FileMode.Open, isf);
      try
      {
            StreamReader sr = new StreamReader(isfs);
            userName = sr.ReadToEnd();
            sr.Close();
      }
      catch (Exception e) { }
      finally
      {
            isf.Dispose();
      }
      return userName;
}

Working example play demo - (remember to refresh web page F5)

Source code is below in “source code” section.

Where is that place

To find a place where exactly is our file with user's name, we have to use debugger in Visual Studio. Place breakpoint on isf variable and run application in debug mode.

Variable "m_AppFilePath" contain real path to Isolated Storage directory and file with user's name. This path is not easy to remember and it could looks like this

"C:\\Users\\ToJaUser\\AppData\\LocalLow\\Microsoft\\Silverlight\\is\\3tumcpvn.hf1\\wrelfaen.uut\\1\\s\\rtqyd4tgtuurqnzlqaf3otinrvcefdf4aeqlkxhw0dltde2t2uaaaeaa\\f"

Deleting isolated storage

If we don't want to keep any more data for Silverlight application in Isolated Storage, we can write program to clear this space or just click right button on any Silverlight application and choose "Silverlight Configuration"

Then go to "Application Storage" tab.

In this window we can see all information about every Silverlight application which saved data on our disk. We have also opportunity to delete these files with only one click.

Source code

Source code

Source code - mirror

Working demo

Run demo

mirror

Resources

MSDN System.IO.IsolatedStorage Namespace - link

“Switch On The Code” blog - link – it’s a little overdue but this was my first article about Isolated Storage Memory which I found few months ago.

Bests Regards ,
Jacek Ciereszko
also http://jacekciereszko.pl – blog in polish

Full Screen mode in Silverlight 2.0 Beta 2 applications

Jacek Ciereszko — Mon, 09 Jun 2008 23:31:42 GMT

This time I would like to show, how to create full screen in Silverlight 2.0 Beta 2.0. Changing application to full screen using only "Application.Current.Host.Content.IsFullScreen" is nothing special because only web browser's window is changing. Our application, have still the same size like before switching to full screen state.

So how to resize application, so it will change simultaneously with web browser? Solution is very simple and all we have to do is use transformations.

Let's start with simple full screen. To switch to full screen mode we have to run only this code:

Application.Current.Host.Content.IsFullScreen = !Application.Current.Host.Content.IsFullScreen;

Now, we can add button to invoke code above.

Page.xaml:
<Button Content="Full Screen" Click="Button_Click" />
Page.xaml.cs: 
private void Button_Click(object sender, RoutedEventArgs e)
{
   Application.Current.Host.Content.IsFullScreen = !Application.Current.Host.Content.IsFullScreen;
}

If you run your application now, you will see that full screen is already working and you can switch views by pushing the button.

So we have full screen but our application still have the same size.. Let's do something with that.

First we have to add ScaleTransform in Page.xaml code:

 <Grid.RenderTransform>
    <ScaleTransform ScaleX="1" ScaleY="1" x:Name="RootLayoutScaleTransform" />
 </Grid.RenderTransform>

and then some code in Page.xaml.cs. In constructor we have to remember original size

_oldHeight = this.Height;
_oldWidth = this.Width;

and add some methods to work with resize and full screen events

Application.Current.Host.Content.Resized += new EventHandler(Content_Resized);
Application.Current.Host.Content.FullScreenChanged += new EventHandler(Content_Resized);
void Content_Resized(object sender, EventArgs e)
{
  double currentWidth = Application.Current.Host.Content.ActualWidth;
  double currentHeight = Application.Current.Host.Content.ActualHeight;
  double uniformScaleAmount = Math.Min((currentWidth / _oldWidth), (currentHeight / _oldHeight));
  RootLayoutScaleTransform.ScaleX = uniformScaleAmount;
  RootLayoutScaleTransform.ScaleY = uniformScaleAmount;
}

FIN, our application is ready! It can resize with Web Browser's window and also when we turn on/off full screen mode.

But what happen if we use mouse and we have to read coordinates? Mouse’s coordinates are now not scaled, so all we have to do, is divide these points by our variable ”uniformScaleAmount”.

double currentY = e.GetPosition(null).Y / uniformScaleAmount;
double currentX = e.GetPosition(null).X / uniformScaleAmount;

Constraints (Update 08-07-2008)

I would like to add, that we have also few constraints. Namely, code above ( ..IsFullScreen != ..IsFullScreen) can be used only in event handler, invoked by user. So we can change application to full screen mode, only by clicking mouse on something or by pressing key on keyboard. This is because of security reasons. None of us, want to see advertisement, created in Silverlight, which will appear all the time and always in full screen mode ;)

Another constrains are keyboard and mouse functionalities in full screen mode, which are reduce to only:

arrows keys and space bar on keyboard
mouse buttons (even mouse wheel doesn't work!)

The last one is really pain in my ass, because then applications written in Deep Zoom Composer in full screen mode, do not have zoom functionality. We can add keys to zoom but this is not the same fun like with mouse!

You can find more about constraints in MSDN link.

FIN

OK, now we have all that we can imagine. Our solution is simple and it can be easily applied to every application. It will be nice and very useful feature in every project.

Source code: source code

mirror

Working demo: play demo (Resize window and click on button!)

mirror

Working Example (Resize it or turn on Full Screen mode)

Resources

Mike Snows's blog link
Jeff Blankenburg's blog link

Sorry for my English. I hope you can understand it.
Jacek Ciereszko
polish blog: http://jacekciereszko.pl/

Win the Web and Discover Yourself! – Final results

Jacek Ciereszko — Tue, 03 Jun 2008 21:22:24 GMT

I am glad to announce that we have winners of Central and Eastern Europe of “Win The Web and Discover Yourself!” contest in 2008. And the winners are:

Best Student Team: HP Team from Poland (89 points)

Prize: 3 free tickets to TechEd in Barcelona !

Best Company: Team Carnation from Hungary (91 points)

(I don’t have image. Send me If you have any.)

Prize: engagement with the Microsoft Innovation Center team in Copenhagen!

About contest

Challenge took place almost two weeks ago (17-18 May) and consisted in creating one main application and three extra tasks, during only 24 hours of development with only a couple of snack breaks and no time for sleep. All participants started coding at 12:00 on Saturday and finished at 12:00 on Sunday.

The main task consisted in creating a web application for monitoring a fleet of lorries for a cargo forwarding company. The contestants were encouraged to take advantage of such cutting-edge Microsoft technologies as Silverlight, Virtual Earth, Windows Communication Foundation Services, LINQ to Database, live.com services, etc.

Winners in countries:

Czech

1st: team Helios
2nd: team Code4Fun
3rd: team dotNETfellas

Hungarian

1st: Digitalmania (Student first prize)
1st: Carnation (Best Company)
2nd. Bounch of mice

Fair Play : Team Agysejt and Team Technik

Interware's special prize: Northwind

ITSecure's special prize: The Turing

Polish

1st: HP Team (me and my team)
2nd: UTP.NET TEAM
3rd: Devenue

Ukrainian

1st (student team): Best Future
1st (company): SoftServe
2nd : Ukrainian students
3rd: CTeam

And the reason why I am so happy about this is that I was one of participants and a member of them (HP TEAM) which won Polish and European part of contest. Members of HP TEAM: Michal Drozdowicz, Jakub Korczak and me, Jacek Ciereszko.

But because it’s not nice to boast I will just show our applications. ;)

Our Applications (Silverlight 2.0 Beta 1)

First we had to create entry application to participate in contest. We had a list of propositions and every team had to choose one and implement it. It was mandatory rule to participate in contest.

I and my team (HP TEAM) chose solitaire game. We create application using Silverlight and you can play this game here:

Solitaire

The main application and Task 2 are connected to one application and you can see it here:

Main Application

Before you say something wrong or you find a bug, please remember that all entrants had only 24 hours and we didn’t have time to write tests and implements all features.

More information

My polish blog: link

Summary

The reason why I wrote this post is because I wanted to thank to organizers. In this year they gave chance to participate also for people from other countries, like Poland. I hope that in next year this contest will be in all European countries and we all meet again.

See you on Tech-Ed 2008 (Barcelona, Spain),
Jacek Ciereszko

My personal view on conference "Communities to Communities 2008" Poland

SilverBlog — Mon, 07 Apr 2008 08:39:39 GMT

So now it's over. Conference is finished but we will all remember the best moments spent in last Saturday (04.07.2008). The pizza, gifts and knowledge about new things which we all learned is priceless and that's why I would like to thanks to all speakers and organizers.

I also added some pictures from conference:

1. Welcome

2. Maciej Szczepański and Paweł Leśnikowski in Test Driven Development (TDD) in practice.

3. Martin Kulov and "Debugging and Crash Dump Analysis of ASP.NET Web Sites".

4. Jarosław Kowalski with subject: "Introduction to Entity Framework".

5. Dino Esposito and "Understanding Goals and Features of the ASP.NET MVC Framework".

6. A little competition

7. Marcin Celej, Michał Brzozowski and ".NET Developer Toolbox A.D. 2008". (I don't have picture, sorry).

8. Organizers

Organizers: Daniel Arak, Michał Grzegorzewski, Paweł Potasiński, Marek Byszewski, Aneta Sidorowicz, Michał Chaniewski, Joanna Grzywna, Szymon Kobalczyk, Paweł Łukasik, Łukasz Olbromski, Łukasz Gąsior, Marcin Samelak, Maciek Paczewski, Karol Stilger and Justyna Spychała. Thank you very much!

9. Me and Dino :D

10. Martin Kulov, Paweł Potasiński, Dino Esposito, Paweł Leśnikowski and me.

If you can read polish texts you can find more on http://jacekciereszko.pl/2008/04/moje-wraenia-po-c2c-materiay.html

Jacek Ciereszko

Button as a content of ToolTip from Button in Button

SilverBlog — Thu, 03 Apr 2008 08:00:10 GMT

In my next article I would like to present simple demo with Button placed in another Button and so forth.

First I tried to show ToolTip inside button from another Button's ToolTip but It doesn't work, only one tooltip can be displaied at one time.

So I put many buttons inside others. I added also tooltip with video and buton inside Tooltip. Everything is showed on demo.

Demo:

Source Code: Source Code (ContentInSL.zip)

Polish mirror of this article: http://jacekciereszko.pl/2008/04/button-jako-content-tooltipa-z-buttona.html

Jacek Ciereszko

Ping pong with html and Silverlight 2.0

SilverBlog — Mon, 31 Mar 2008 10:54:04 GMT

I created demo that show how to connect Silverlight 2.0 with code html. This demo is like a game ping-pong, but it is not really game because you not suppose to play but learn Silverlight 2.0 !

My demo from my polish blog (in polish) http://jacekciereszko.pl/2008/04/ping-pong-with-html-and-silverlight-20.html

Source code: http://pizza-warszawa.hostedwindows.pl/blog_resources/HtmlPingPong.zip

Demo

Jacek Ciereszko