Category Archives: Development Tools

EvenTiles from Start to Finish–Part 6

In the previous episode of this series about how to develop a Windows Phone application from scratch we used IsolatedStorage to persist some data. Since IsolatedStorage is a file store on a Windows Phone device, for exclusive use by a single application, it can be a challenge to look at its contents. Luckily, the Windows Phone 7.1 SDK has a tool available to explore IsolatedStorage contents. In this episode of EvenTiles we will explore this Isolated Storage Explorer Tool.

The Isolated Storage Explorer Tool is a command line tool, which is installed together with the Windows Phone 7.1 SDK in the following folder:

C:\Program Files (x86)\Microsoft SDKs\Windows Phone\v7.1\Tools (64 bit OS)
or
C:\Program Files\Microsoft SDKs\Windows Phone\v7.1\Tools (32 bit OS)

The tool itself has a lot of parameters, to get contents from IsolatedStorage, to write contents to IsolatedStorage, to specify an application and to specify a device. In a command prompt some limited help information is available:

image

In order to retrieve our ApplicationSettings from IsolatedStorage for EvenTiles, the first thing we need to know is the ProductID for our application. This ide can be found in the WMAppManifest.xml file.

WMAppManifest.xml
  1. <Deployment xmlns="http://schemas.microsoft.com/windowsphone/2009/deployment" AppPlatformVersion="7.1">
  2.   <App xmlns="" ProductID="{883385e6-52e5-4835-83db-8a17499b5767}" Title="EvenTiles"

The next thing we need to do is make sure that the Emulator is started (or a physical device is connected). Either should have the application installed, but it is not necessary to have the application running. After passing the following command,

image

the folder C:\iso will contain a snapshot of our application’s IsolatedStorage.

image

When we drag and drop the _ApplicationSettings file to Visual Studio 2010, you can see that its contents are XML data, representing a Dictionary with one single entry defined in it, matching our Secondary Tile’s back side string.

image

You might not like using a command line tool to explorer IsolatedStorage. In that case, there is good news for you. If you browse to http://wptools.codeplex.com/, you will find the Windows Phone Power Tools for download. This handy collection of tools embeds the different SDK tools including the Isolated Storage Explorer Tool inside a Windows application. With that application you can explore your application’s IsolatedStorage as well. Using the power tool, it is also easy to write new or modified files to your application’s IsolatedStorage. The latter makes a lot of sense if you want to test new versions of applications against old contents in IsolatedStorage, for instance to migrate old files to new versions.

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The following video shows the Isolated Storage Explorer Tool and the Windows Phone Power Tools in action.

Using the Isolated Storage Explorer Tool and the Windows Phone Power Tools

So this time we did not add functionality to our EvenTiles application, but it is important to learn about useful tools to help us develop our applications as well. In the next episode we will talk about Tombstoning and Fast Application switching and what we need to do in our application to support these two important execution states on Windows Phone devices.

imageIf you want to see EvenTiles already in action on your Windows Phone, you can install the latest release from Marketplace. Remember that this application is not meant to be extremely useful, although it contains similar functionality that “serious” applications have. All functionality that you can find in the released version of EvenTiles will be covered in the upcoming episodes of this blog series, together with all source code. Just go ahead and get your free copy of EvenTiles from Marketplace at this location: http://www.windowsphone.com/en-US/search?q=EvenTiles (or search on your phone for EvenTiles in the Marketplace application).

EvenTiles from Start to Finish–Part 5

In episode number four of this series about how to develop a Windows Phone application from scratch we created the SettingsPage using a combination of Expression Blend and Visual Studio 2010. The SettingsPage has limited functionality, but it can modify a string that will eventually be displayed on the backside of a Secondary Tile. In this episode we will take a look at how to store data in IsolatedStorage.

If you watched the video of episode 4 you have noticed that the string containing the text to be eventually displayed on the Secondary Tile’s backside was not saved when the application was closed, because a default string showed up when the application was started again. In order to store the string so it will be available when the application starts again, we are going to store it into a specific part of the our IsolatedStorage. IsolatedStorage can be used to store files and system settings. It just acts as a hard drive with one little but important difference. IsolatedStorage is …. isolated. Everything that is stored in IsolatedStorage is exclusively available for the application that owns it, so other applications can not access it.

When a Windows Phone application starts, it will be running in the foreground, with its MainPage visible. As long as the user is working with the application, it remains n the foreground. An application can be terminated by the user by pressing the Back key on the phone until the last page of the application will be closed. An application can also be moved to the background. This happens when the user activates another application, or for instance when the user answers a phone call. On starting, a Launching event is raised. The App.xaml.cs file already has event handlers defined for the Launching and Closing events. These are the events that we are going to use to store / retrieve our string containing the backside text for our Secondary Tile.

NOTE: The sample code, retrieving and storing data in the Launching / Closing event works fine. However, all code executing upon firing those events has a time limit of 10 seconds. If an event handler takes longer to execute, the application will be immediately terminated. If you have much data to store / retrieve, you should take an alternative approach. You can for instance make use of a separate thread in those situations to retrieve / store information. To keep our sample lean and mean, we will directly retrieve / store data into IsolatedStorage from within the Launching / Closing event handlers.

Since all functionality is already available inside the SettingsPage to store the backside text of the Secondary Tile, we are only adding some functionality to the App.xaml.cs file. First thing to do is get access to the IsolatedStorageSettings for our application, which is in fact a dictionary in which values can be stored / retrieved through a key. The IsolatedStorageSettings are implemented as a singleton and are created the first time we try to access them. IsoloatedStorageSettings can be accessed from inside our entire application, although right now we will only use IsolatedStorageSettings inside the App.xaml.cs file.

IsolatedStorageSettings
  1. public const string DefaultSecBackContent = "Having an even # of tiles on my StartScreen";
  2. public const string keyActSecBackContent = "K_ASBC";
  3.  
  4. public static string ActualSecBackContent { get; set; }
  5.  
  6. private IsolatedStorageSettings appSettings = IsolatedStorageSettings.ApplicationSettings;

In the code snippet you can see a declaration of a key (just a string variable) that is used to store / retrieve the string containing content for the back side of a Secondary Tile. You can also see how a private variable is declared that is initialized with the one and only instance of our application’s settings in IsolatedStorage.

Application_Launching
  1. // Code to execute when the application is launching (eg, from Start)
  2. // This code will not execute when the application is reactivated
  3. private void Application_Launching(object sender, LaunchingEventArgs e)
  4. {
  5.     if (!appSettings.Contains(keyActSecBackContent))
  6.     {
  7.         appSettings[keyActSecBackContent] = DefaultSecBackContent;
  8.     }
  9.     ActualSecBackContent = (string)appSettings[keyActSecBackContent];
  10. }

Each time the application is started, the Application_Launching method will be executed. In this method we check if an object is stored under the key keyActSecBackContent. If this is not the case, we create a new entry in the dictionary of application settings and assign it with a default text that can be written to the back side of the Secondary Tile. If an entry already exists (which is basically always after creating one during the very first time), we retrieve the actual string from that entry. Since an application settings dictionary stores objects, we need to cast the actual value to a string.

When the application is terminated, the contents of the string that contains the text for the back side of the Secondary Tile might have been changed in the SettingsPage. That is the reason why we store that string always when the application ends.

Application_Closing
  1. // Code to execute when the application is closing (eg, user hit Back)
  2. // This code will not execute when the application is deactivated
  3. private void Application_Closing(object sender, ClosingEventArgs e)
  4. {
  5.     appSettings[keyActSecBackContent] = ActualSecBackContent;
  6. }

It looks like we now have stored our application settings properly. However, that is not entirely the case, since our application might be temporarily interrupted because the user can start other applications without terminating our application. In those situations we have to take a look at the life cycle of an application. That will be topic of another episode of EvenTiles. It is also interesting to take a look at exactly what information is stored in IsolatedStorage. In order to do that, you can make use of the Isolated Storage Explorer Tool, a handy little tool that will be covered in episode six of EvenTiles.

In the following video you can see all the steps that you need to make application settings persistent and to retrieve them each time the application starts again.

Using IsolatedStorage to store ApplicationSettings

Note: Every now and then I will make sure that you can download all source code that we created so far. I strongly recommend you to do so and to start experimenting with that code. After all, looking at real code, modifying it and understanding your modifications will hopefully help you to become a great Windows Phone developer fast.

If you want to keep up with the code of EvenTiles that is available until now, you can download it as a Zip file from this location. After downloading and unzipping it, you can open the EvenTiles solution in Visual Studio 2010 Express for Windows Phone. You must have the Windows Phone SDK 7.1 installed on your development system to do so. If you have a developer unlocked phone you can deploy the application to your phone, if you don’t have a developer unlocked phone you can still experiment with this application inside the emulator.

EvenTiles from Start to Finish–Part 2

In the first part of this series about how to develop a Windows Phone application from scratch we looked at the initial project and how to initialize the Application Tile by setting elements in the manifest file. Today we will add an ApplicationBar to our application and we will add page navigation as well. We simply take off where we finished in Part 1. Adding an application bar is actually easier from within Expression Blend. This tool can be used to design and prototype Windows Phone applications. The advantages of using Expression Blend to add the application bar are:

  • immediate visual feedback;
  • simple selection / insertion of application bar icons
  • simple reordering possibilities for application bar icons en menu items.

imageVisual Studio can work closely together with Expression Blend. Changes in one environment will be visible in the other environment (usually changed files must only be saved or a project must be rebuilt in order to achieve this). If a solution is already open in Visual Studio, you can start Expression Blend from within the Project Menu as shown. Even though you can use Expression Blend to add code to your Windows Phone pages, you probably want to limit doing so, since you don’t have Intellisense available, which is one of the great features of Visual Studio that really makes entering code easy. You can immediately see that you are in a different environment when looking at Expression Blend. Its default theme color is dark. Something else that is immediately noticeable is the large amount of windows, options and choices available inside Expression Blend. It surely will take you some time to feel comfortable in this powerful design tool.

image

What you can see here is Expression Blend showing the MainPage of our EvenTiles application. You can also see how to select an ApplicationBarIcon in the collection of ApplicationBarIcon buttons. Besides concentrating on creating a (static) UI for a Windows Phone application, Expression Blend is also a fantastic tool to create different visual states and animations. We are still in the early stages of application development in this series, but more in depth usage of Expression Blend will definitely follow later on. For now we will just add a little bit of functionality to our application. Using Expression Blend, two new pages have been added to the project, a Settings Page and an About Page. Both these pages only contain a filled title section. Right now, the only functionality that will be added to the application is code to navigate to each of the two empty pages when the corresponding ApplicationBar buttons are clicked. The following code snippet shows the ApplicationBar that was created with Expression Blend in XAML, and already includes Click event handlers:

ApplicationBar on MainPage
  1. <phone:PhoneApplicationPage.ApplicationBar>
  2.     <shell:ApplicationBar Opacity="0">
  3.         <shell:ApplicationBarIconButton IconUri="/icons/appbar.feature.settings.rest.png"
  4.                                         IsEnabled="True"
  5.                                         Text="settings"
  6.                                         Click="Settings_Click" />
  7.         <shell:ApplicationBarIconButton IconUri="/icons/appbar.questionmark.rest.png"
  8.                                         IsEnabled="True"
  9.                                         Text="about"
  10.                                         Click="About_Click" />
  11.     </shell:ApplicationBar>
  12. </phone:PhoneApplicationPage.ApplicationBar>

To add code to the Click event handers, we are using the C# code behind file, belonging to the MainPage.

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To create entries in the code behind file for both Click event handlers (and in that way connecting XAML to code), you can right click on the event handler in XAML and selecting Navigate to Event Handler entry from the shown popup menu. The code in the event handlers is very simple, using the NavigationService to navigate to another page by providing a Uri that contains the page name.

Navigating to other pages
  1. private void Settings_Click(object sender, EventArgs e)
  2. {
  3.     NavigationService.Navigate(new Uri("/SettingsPage.xaml", UriKind.Relative));
  4. }
  5.  
  6. private void About_Click(object sender, EventArgs e)
  7. {
  8.     NavigationService.Navigate(new Uri("/AboutPage.xaml", UriKind.Relative));
  9. }

After deploying the application to the emulator, the Main Page shows an ApplicationBar. Clicking on either of the two ApplicationBar buttons results in navigating to another page inside the application. The following video shows all steps to create the ApplicationBar, the additional pages and the code to navigate from page to page:

Adding an ApplicationBar and showing page navigation

LiveTiles will be extended soon. In the next episode we will take a look at the Silverlight toolkit, Page Transitions and additional controls that are available in the Silverlight toolkit. Make sure to lookout for part three in this series about Windows Phone application development.

A new Windows Phone 7 Device (Emulator)?

Just a few hours ago, the Windows Phone Developer Tools Update was released by Microsoft. This update is specifically for Windows Phone application developers to allow them to build apps that are ready for the upcoming Windows Phone OS update. After installation of the tools update, you can test copy and paste functionality on the (also updated) emulator.

In order to start working with the updated tools, you will need to download the Windows Phone Developer Tool update and a separate Visual Studio 2010 update. Also make sure to read the Release Notes for the update. The order of installation for the separate tools is not important but you have to install them both. A little more background information about the latest WPDT update can be found on the Windows Phone Developer Blog.

It is expected that all existing apps that are already published in Marketplace will continue to work, both on phones that will be updated to the new version of the OS that will be available later, but also on phones that are not updated. To show the new copy and paste feature of Windows Phone 7 in action I have created a small application that takes a URL and allows that URL to be copied in Internet Explorer on the Windows Phone Emulator. To see this little application in action, just take a look at this video.

Windows Phone 7 Copy and Paste with the WPDT January Update.

Another year, another MIX

Last year in April, the place to be was Las Vegas, NV for MIX 10. During this conference  Windows Phone 7 was officially introduced. Immediately after MIX 10 the development tools were available for download. Also, the great content that was presented during MIX 10 is still available for you to watch. It seems hard to believe that we have been developing Windows Phone 7 applications for less than a year. We really have come a long way. Windows Phone 7 is released in a number of countries, devices are available in many more countries and the list of applications being released on Marketplace is growing rapidly.

Update: It is no longer possible to vote for MIX11 sessions. Thank you very much if you voted for one (or more) of my sessions that are listed below.

This year, before attending MIX, there is a call to action for everybody (especially for you since you are reading this blog post). You are in control of voting for a number of sessions of which the most favorite sessions will be presented at MIX. Amongst the Windows Phone 7 sessions that are up for voting, three were submitted by me. I am counting on you to help me become part of MIX 11. If you like the things I am writing on this blog or if you have seen me speaking in the past, or just because you are visiting this website, make sure to vote for my MIX 11 sessions. You can vote for all these sessions by clicking on the links. You can only vote for each session once on a physical machine, but of course I can’t prevent you against voting multiple times on different machines. Here are the sessions I submitted for voting (clicking on the individual links will bring you to the voting page for the particular sessions):

  • Windows Phone 7: Application Architecture

    When you start developing Silverlight applications for Windows Phone 7 using Visual Studio 2010, you might be tempted to use code behind to connect your user interface (written in XAML) to your functionality (written in C#). In this sample filled presentation, Maarten Struys explains why this relatively easy approach is not necessarily the best approach to create testable, maintainable and great Windows Phone 7 applications. During the presentation, the power of DataBinding in Silverlight will be revealed and a traditional application, using code behind will be converted into an application that makes use of the MVVM design pattern.

  • Windows Phone 7 and the Cloud: The Sky is The Limit

    Windows Phone 7 is a powerful platform for which you can create great stand-alone Silverlight based applications. To create Windows Phone 7 applications with limitless processing resources and virtually unlimited storage capacity, Windows Azure and Windows Phone 7 are great companions. In this sample filled presentation, Maarten Struys shows you how to create a Windows Phone 7 application together with a Windows Azure based back-end. He explains how the application can efficiently communicate with the back-end using a REST based Web Client interface. He also shows you how to efficiently cache information locally on the phone to make Windows Phone 7 applications operate independent of network connectivity. After attending this session you know how to create Windows Phone 7 applications that are as powerful as server applications.

  • Fast starting and State Saving Windows Phone 7 Applications

    In this sample filled presentation, Maarten Struys shows you the impact of Tombstoning on Windows Phone 7 applications. He shows you how to store the application’s state and individual page state information efficiently. He also explains how your application can start fast and efficiently by making use of multithreading and asynchronous programming techniques. After attending this presentation, your Windows Phone 7 Tombstone headaches will be history and your end users will be happy with your fast starting applications.

Thank you very much for voting! I really hope to see you in Las Vegas between April 12 – April 14 for MIX 11. If you are planning to visit MIX 11, make sure to register before February 11 to benefit from a nice discount.