Service post–domain chaos finally has an end ( is back)




Some of you might have noticed that a lot of chaos was going on with my domain in the last few months.

The reason were some serious issues with my old hoster – that would be a evil long post to describe.

As backup, I used, a virtual machine on Azure that I set up to play around and learn more about webservers on Linux. Sadly, I just don’t have enough time to dive deeper into that.

Now that is finally working again, this will be the primary address to go to.

I will shut down the server on Azure soon. If you come across links for my blog with, just remove the ‘cloudapp.’ part of the link, and you will end on the corresponding blog post on

Also my apps for Windows Phone and Windows 8 are working again (some small updates will come with an update).

Sorry for any inconveniences caused by this.

Posted by msicc in Archive, 0 comments

[Updated] NFC Toolkit uri schemes


If you are following me, you might have noticed that uri schemes actually are playing a big role in my Windows Phone apps. (read more)

NFC Toolkit, one of my main projects, offers now also the possibility to interact with your apps.

One of the unique features of NFC Toolkit is profiles. Profiles are designed to open up to 5 settings pages in a row (as directly setting them is not possible because of OS restrictions). At the end of a profile, an extra from within the app or another app can be launched.

In Phase I, NFC Toolkit enables other developers to add their custom uri association/scheme to the list of launchable apps in profiles.

Here is how the uri needs to be formatted to work:


I will add more uri associations with the next updates and update this post with them.

[Update 2]

Starting with version of NFC Toolkit, I added new uri schemes to enable you to write data on NFC tags. Here is the list of possible writing records:

  • website record:
"nfctoolkit:writetag?type=smartposter&url=<url>&title=<title of the website>&languagecode=<two letter lang code (standard: en)>"
  •   text record:
"nfctoolkit:writetag?type=text&content=<your text here>&languagecode=<two letter lang code (standard: en)>"
  • send mail record:
  •  settings page:
//supported pages: flight mode, cellular, WiFi, Bluetooth, location, lock screen
"nfctoolkit:writetag?type=settings&page=<settings page name as listed above>"
  •  launch system app:
//supported pages: 
//"Alarm", "background tasks", "brightness settings", "Bing Vision", "Calculator", "Calendar", "call history", 
//"Camera", "Data Sense", "date + time settings", "ease of access", "find my phone", "Games", "Help+Tips", 
//"Internet Explorer", "internet sharing", "keyboard settings", "kid's corner settings", "language + region settings", 
//"Maps",  "Messaging", "Music+Videos", "Office", "OneNote", "People", "Phone", "phone information", "Photos", 
//"Rooms", "SIM Applications", "Start", "Store", "theme settings", "Wallet"
"nfctoolkit:writetag?type=sysapp&name=<system app name as listed above>"
  •  launch any app by name or publisher name:
//launches the store page search in NFC Toolkit and searches for the app/publisher
"nfctoolkit:writetag?type=launchapp&appname=<app name or publisher name>"

On top of that, I added an uri scheme that allows a plain launch of NFC Toolkit:


I updated my custom uri scheme test app as well for you. Download it here: CustomUriSchemeTestApp

Happy coding everyone!




Posted by msicc in Archive, 5 comments

Experiment: using for Support, Feedback and FAQ

On my daily job, I am working as a Mobile Hardware Support Agent of a German  carrier. Because of that, I know how important a good support for customers (=users) is – and also, a little knowledge base where users can find most probably an answer for their  questions.

I want my customers to be satisfied. As an indie developer, I have a little problem: I don’t have a support team that catches all the support questions for me. I need to do this by myself. Until now, I am doing this by using a send-me-a-mail button in my apps. However, due to the fact that I have a 9to5 job and a family besides developing apps, time is a bit limited for me. I searched for some solutions to improve the way I am doing my customer service, and uservoice seems like a good tool to improve my customer service a lot.

As you can see at the feature comparison list of uservoice, the free account already allows you to do a lot of things: It is free for one support agent – perfect for an indie developer like me.

What can you do with uservoice?

uservoice has a lot of features:

  • support ticket system
  • knowledge base
  • feedback system/forum
  • and many more, if you are going for a paid plan

Let’s have a look at the first three features:

Support ticket system

Adding the ticketing system is very easy. You just need a EMailComposeTask pointing to your ticket system. Your standard mail address for that will be: “tickets@<yourname>”. This is how a received ticket looks like:

Screenshot (289)

Answering to a user is as easy as writing an email – plus you have a ticket history at a glance.

On top of that, you are able to insert a so called ‘canned response’ based on your knowledge base:

Screenshot (290)

Knowledge base

You can build up a knowledge base for your apps.

Screenshot (286)

In the left menu at the bottom at your admin console, you will find the ‘ARTICLES’ section. This is where all the knowledge base articles are collected.

You can create also topics within that KB. I did so for all of my apps:

Screenshot (286)

This way, you can use your free account to support all of your apps with FAQ/KB articles – pretty easy.

Here is how to set up a new article: after clicking on ‘All articles’, there is a ‘New Article’ button on the right side of your screen. Click on that, you will see this on the right hand side:

Screenshot (287)

You can set up the article name, the text and the topic as well as the position you want to show it up in your knowledge base.

You can take a look at my knowledge base here:

How can you use this in your apps? I plan to create an API wrapper for their C# SDK, which is not compatible with Windows Phone at the moment. I will write another blog post for that. Luckily, uservoice as a very nice mobile interface, so you can start off with a simple WebBrowserTask to open your knowledge base:


Technically, it would be possible to use a WebBrowser control, too. But you would need to code more to get a proper browsing handling.

Feedback system/forum

Some of you might be already familiar with the feedback or idea forum of uservoice (even Microsoft uses this). This time, we look at the other side of the forum, from our admin console:

Screenshot (292)

You have a similar view to what users see, but there are some more parts to control your forum. As a free user, you have only one forum, so it might be useful if you add the app name in front of the title of an idea. You can respond, take notes, and change the status of the ideas:

Screenshot (293)

To integrate the feedback function in your app, you can again use a WebBrowserTask to open the mobile page of your idea forum:


These are the first simple steps to create your own customer support system with uservoice. Like I said before, I will write a Windows Phone wrapper to get this into an app as native, and will share it here with you all.

Until the next post, happy coding!

Posted by msicc in Archive, 0 comments

A simple approach to remove QueryStrings from NavigationContext on Windows Phone


Like most of you know, I am currently adding a lot of new features to my NFC Toolkit for Windows Phone.

Today, my coding session is all about uri schemes again. I successfully added some new uri schemes that you will be able to use soon.

However, if you start an app via an uri scheme, you will have  QueryStrings in your NavigationContext on the desired ApplicationPage. If a user continues to use your app, navigates away from the launched page and back to it, the code based on your QueryStrings will be called again.

As I am a daily Windows Phone user by myself, I know this is somewhat annoying. So I searched for a solution. I first thought about removing entries in the BackStack, but that would need a lot of code if you are running an application that has more than two pages – you’ll need to add methods to check if you are coming from an uri scheme, clear the BackStack, pass the parameters to the next page, get back to your MainPage, check the parameters again. Totally unusable in my opinion.

The NavigationContext.QueryString property has a Remove() method as I found out while researching a bit more – that’s what I am using now to get the result I want – make the app running like it was launched normally without uri scheme after the action has taken place.

I found some examples that are using the method in the  OnNavigatedTo() event. I don’t think that’s the right way, as I often happen to have some more code in this event, and it will probably break other functionality. I am using the OnNavigatedFrom() event.

Add this lines of code for every QueryString you want to remove (depending on your method structure, it is ok to remove only the QueryString you rely on in your further code, additional parameters can be still there ):

protected override void OnNavigatedFrom(NavigationEventArgs e)
   if (NavigationContext.QueryString.ContainsKey("key1"))
   if (NavigationContext.QueryString.ContainsKey("key2"))

This way, if you are navigating to another page in your app or even if the user uses the Windows Button, the corresponding QueryString will be removed – and your users are able to use the app as they would have launch it without an uri scheme.

However, that’s not all. When your app get’s Tombstoned, the UriMapper will map the uri scheme again on Activation – not what you might want. To get around this, I use a simple Boolean, set it to true when I am coming back from Tombstoning:

private void Application_Activated(object sender, ActivatedEventArgs e)
    if (!e.IsApplicationInstancePreserved)
        wasTombstoned = true;  

Now the only thing you will need to to is to add

&& App.wasTombstoned == false

as second argument to your QueryString clause – that’s it!

I am not sure if this is a good approach or not, but it works. It allows you to launch your uri scheme, and enables the user to use your app after that as it would have been launched normally. If you have other ways to get the same result, feel free to leave a comment below.

Otherwise, I hope this post is helpful for some of you.

Happy coding!

Posted by msicc in Archive, 5 comments

Merry Xmas, everyone!




This year was an amazing year. We got a lot of new devices, great apps, and a lot of development work was done.

Now, with Xmas around the corner, I want to wish all of you a

Merry Christmas!

After the xmas days, I will start a new series here on my blog, together with my review post of 2013.

Enjoy your family time, and may god bless you all!

Posted by msicc in Archive, 0 comments

[Updated] Why Windows Phone apps deserve a custom uri scheme (and how to add a simple launch uri)


Microsoft introduced custom uri schemes or uri associations in Windows Phone 8 along with the ability to launch apps based on a file type.

Sadly, this feature is not used across a broad range of apps yet. Why am I so interested in that point? I am going to explain you.

First, there is one big issue: You can share any app via NFC, and launch any app from the Store via NFC tag that has a launch app record. But you cannot launch any apps from your app – just those that have implemented a custom uri scheme. On the other two big operating systems, sharing between apps is meanwhile a standard feature used by a lot of developers.

Most of the settings pages have one of those uri schemes, for example the Wi-Fi settings page can be launched with this simple line of code:

await Windows.System.Launcher.LaunchUriAsync(new Uri("ms-settings-wifi:"));

I don’t know if other developers just don’t know about this feature or if they don’t think it is necessary. I talked to a lot of users of my app NFC Toolkit for Windows Phone 8, and all asked me to add the possibility to launch a desired app at the end of my profiles (if you don’t know, my profiles launch programmable sequence of settings pages).

Searching for a solution to satisfy my user, I spent a few days with researching of all possibilities and talking to other developers. Some of them wanted use cases for adding that feature, here are three:

  • Every day I leave for work, I disable Wi-Fi, activate Bluetooth and switch the cellular connection from 2G to 3G/4G. I often use Nokia Music to listen to music while driving to work (about 45 minutes). This is one of the use cases.
  • The second scenario should be also familiar to some of you: I switch off all data connections because otherwise, my phone would ring very often during the night. In the morning, I switch them back on and check for news with a feed reader app. This would fit perfectly into a profile that I save on a NFC tag or launch via secondary tile.
  • Third one: there are a lot of blog reader apps out there. Sure, Windows Phone has social networks built in – but only Facebook (user only), Twitter and LinkedIn. What if I want to share to another network, for example Geeklist? Then I have to copy and paste instead of just hitting the share button.

There are more use cases, but I am leaving you with these three for the moment.

Back to the conversations I had with my users. They want and deserve a great user experience. This blog post is part of my efforts to provide users their deserved user experience.

Sadly, for a handful of developers it is not as easy to gain some attention for this. This is why I am trying to get DVLUP on board. By creating a challenge for this, more developers would join to earn the XP. The winners in this case are the users out there, because this way, their user experience will be improved. I know this should be done by Microsoft. In the meantime, it is up to us developers to improve. That’s why I ask you to vote for my idea case on DVLUP here: (the first entry in the list is the one to vote).

There is one reason left why you should add a custom uri scheme to your app. This point is for you, the developer reading this article. You have a free possibility to promote your app across other apps. The most important point: it takes only 5 minutes to add a simple launch uri scheme.

Do you already have a custom uri scheme for your app? Great, then add it to this list: URI Association Schemes List – Nokia Developer Wiki. This way, other developers can use them to interact with your app and bring you new users, too.

To close this article, I want to show you how to add a simple custom uri launch scheme. I have done this with my app Mix Play & Share recently (update submitted, will add it to the list above as soon as it certified).

A simple launch uri – the code

First, open your WMAppManifest.xml by right-clicking on it and Open with… =>XML (Text) Editor.

After the </Tokens> Element, add the following code:

     <Protocol Name="your-custom-uri-scheme-here" NavUriFragment="encodedLaunchUri=%s" TaskID="_default" />

Save and close the Document.

Add a new class to your project. Add the following code in your class:

    class UriSchemeMapper : UriMapperBase
        private string tempUri;

        public override Uri MapUri(Uri uri)
            tempUri = System.Net.HttpUtility.UrlDecode(uri.ToString());

            // updated code begins here:
            if (tempUri.Contains("your-custom-uri-scheme-here"))
                return new Uri("/MainPage.xaml", UriKind.Relative);
            //updated code ends here
            return uri;

To make your app using this custom uri scheme, you just have to add another line of code after the declaration of your RootFrame in App.xaml.cs:

//Handle custom uri scheme
RootFrame.UriMapper = new UriSchemeMapper();

That’s all, your app now is able to be launched by other apps!

You can also add more advanced custom uri schemes (up to 10 per app), to read more about it, check MSDN:

I hope after reading this post, you understand why I think it is important to add a custom uri scheme. With the simple code above, you’re done in 5 minutes.

Update 12/14/2013:

I needed to update the UriMapper class above, because without handling a scheme without parameters we will have no guarantee that the app launches. In my tests it works sometimes and sometimes not, but to make sure your app launches, please handle this case properly.


Until then, happy coding!

Posted by msicc in Archive, 9 comments

How to update a live tile in a background task with web data on Windows 8.1


Like I wrote in my last post, I recently finished a PCL project with a Windows Phone and a Windows 8.1 app. Like the Windows Phone version, also the Windows 8.1 app has a live tile that fetches the same data from WordPress.

Taking advantage of our PCL solution structure, we are able to reuse the JSON data class from our PCL.

However, there are a few things that differ from the Windows Phone background agent.

First, we need to add a new project to our solution. In the new project dialog, select ‘Windows Runtime Component’ in the C# Windows Store section.

To make it a background task, implement the interface IBackgroundTask to the generated class in our Runtime component. In order to make it doing some work, we are going to add the ‘Run’-method that will start our background agent.

Here we are already with the first difference. The Windows Runtime does not support direct async Tasks of type string (I fetch all articles via HttpClient in an async task that returns the JSON string). That’s why we need to wrap it in an IAsyncOperation. To do this, add a new sealed class to your Windows Runtime background agent project.

Here is how the code for the IAyncOperation:

        public IAsyncOperation<string> GetLastPostJsonString(string url)
                return AsyncInfo.Run((System.Threading.CancellationToken ct) => GetInternal(url));
            catch (Exception ex)
            return null;

        private static async Task<string> GetInternal(string url)
                HttpClient getJsonStringClient = new HttpClient();
                getJsonStringClient.DefaultRequestHeaders.IfModifiedSince = DateTime.Now;

                var response = await getJsonStringClient.GetAsync(url);
                var JsonString = await response.Content.ReadAsStringAsync();
                return JsonString;
            catch (Exception ex)
            return null;

Let me explain the code. The IAsyncOperation starts and returns the string of our async Task<string>.  To achieve this, we need to start another async Run that delegates our Task<string> result to the main background task. Unlike a direct HttpClient call, we are not able to save the string directly to an string object. Instead, we need to read the stream.

I highly recommend to wrap this all in try/catch blocks to prevent any crashes of your app.

Let’s go back to our main background task class. Now we are able to fetch the JSON string from web service, we finally can start to implement the Run() method that will actually update our live tiles:

       public async void Run(IBackgroundTaskInstance taskInstance)
               BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

               PostfetcherForTileUpdate fetchJsonString = new PostfetcherForTileUpdate();

               Constants.latestPostsForLiveTileFromWordPressDotComResultString = await fetchJsonString.GetLastPostJsonString(Constants.GetLatestPostsForLiveTileFromWordPressDotComUriString);



           catch (Exception ex)

The Run method needs to implement the Interface for IBackgroundTaskInstance. To inform the OS that our background agent may do work after the Run has returned data, we need to use the GetDeferral() method. If we would do that, it may happen that the task will be closed before all action has taken place.

After getting the JSON String from the IAsyncOperation, we can now write it to an object, call our UpdateTile() method and tell the system that our deferral is completed.

Within the UpdateTile() method, we are going to deserialize the JSON String and update our live tile. There are a lot of considerations for the live tiles in Windows 8 and 8.1, make sure you have read the guidelines for tiles and badges on MSDN. Make also sure you check the tile template catalogue to choose the right templates for your app.

Let’s have a look at the UpdateTile() code:

        private static void UpdateTile()
                //create a new Tile updater and allow it to be added to the notification queue
                var updater = TileUpdateManager.CreateTileUpdaterForApplication();

        //deserialize the JSON string
                var LatestPostFromWordpress = JsonConvert.DeserializeObject<json_data_class_Posts.Posts>(Constants.latestPostsForLiveTileFromWordPressDotComResultString);

        //fill in the Tile Templates
                foreach (var item in LatestPostFromWordpress.posts)
            //supporting both Medium and Wide tiles
                    XmlDocument WidetileXML = TileUpdateManager.GetTemplateContent(TileTemplateType.TileWide310x150PeekImage04);
                    XmlDocument SquareTileXML = TileUpdateManager.GetTemplateContent(TileTemplateType.TileSquare150x150PeekImageAndText04);

            //setting the text on our tiles
                    var title = item.title;
                    WidetileXML.GetElementsByTagName("text")[0].InnerText = title;
                    SquareTileXML.GetElementsByTagName("text")[0].InnerText = title;

            //providing the remote image source 
            //if not empty:
                    if (item.featured_image != string.Empty)
                        XmlNodeList tileImageAttributes = SquareTileXML.GetElementsByTagName("image");
                        ((XmlElement)tileImageAttributes[0]).SetAttribute("src", item.featured_image);
                        ((XmlElement)tileImageAttributes[0]).SetAttribute("alt", "no image");

                        XmlNodeList tileWideImageAttributes = WidetileXML.GetElementsByTagName("image");
                        ((XmlElement)tileWideImageAttributes[0]).SetAttribute("src", item.featured_image);
                        ((XmlElement)tileWideImageAttributes[0]).SetAttribute("alt", "no image");
            //if empty:
                    else if (item.featured_image == string.Empty)
                        XmlNodeList tileImageAttributes = WidetileXML.GetElementsByTagName("image");
            //this image has to be in the main Windows 8.1 project, not in the background task!
                        ((XmlElement)tileImageAttributes[0]).SetAttribute("src", "ms-appx:///Images/NoImgPlaceholderMedium.png");
                        ((XmlElement)tileImageAttributes[0]).SetAttribute("alt", "no image");

                        XmlNodeList tileWideImageAttributes = WidetileXML.GetElementsByTagName("image");
            //this image has to be in the main Windows 8.1 project, not in the background task!
                        ((XmlElement)tileWideImageAttributes[0]).SetAttribute("src", "ms-appx:///Images/NoImgPlaceholderWide.png");
                        ((XmlElement)tileWideImageAttributes[0]).SetAttribute("alt", "no image");

            //perform the update of our live tiles
                    updater.Update(new TileNotification(WidetileXML));
                    updater.Update(new TileNotification(SquareTileXML));
            catch (Exception ex)

To make the background task updating our tile, we need to use the TileUpdateManager class. As we are updating our main tile, we are using the CreateTileUpdaterForApplication() method. To make sure our tile is able to queue our update request, we are setting the EnableNotificationQueue property to true.

After deserializing the JSON string, we fill the Template by using DOM methods. I used the GetElementsByTagName(string) method to find the title and the image ChildNodes in the template. This way, I don’t need to care for the Xml structure.

The title content can be set by using the InnerText property. For providing the images source, we need to go through the NodeList, searching for the image NodeChild and use the SetAttribute() method of the XmlElement class.

With the code above, the tile gets a placeholder image, if the JSON string does not return an url for the  featured image. Important: the placeholder image has to be in your main Windows 8 project, not in the background task project. Make also sure that the image(s) have a unique name and do not use the same file name like your base tile image.

That’s all we need to do in our background task project.

Let’s have a look at our main app project. First, we have to declare our background task to make our app registering for the periodic notifications. Open the Package.appxmanifest of your app and navigate to the ‘Declarations’ tab.

Screenshot (259)

Under ‘Available Declarations’, select ‘Background Tasks’ and ‘Add’.

Screenshot (259)


Under ‘Description’ check the ‘Timer’ Option. Make sure you referenced your background task project and add it as ‘Entry Point’.

That’s all that wee need to set up in the first step. Now we are going to write our method to register the background task:

        //needs to be async because of the BackgroundExecutionManager
        public async void RegisterBackgroundTask()
        // calling the BackgroundExecutionManager
        //this performs the message prompt to the user that allows the update of our tiles and the permissions entry
                var backgroundAccessStatus = await BackgroundExecutionManager.RequestAccessAsync();

        //checking if we have access to set up our live tile
        if (backgroundAccessStatus == BackgroundAccessStatus.AllowedMayUseActiveRealTimeConnectivity ||
                    backgroundAccessStatus == BackgroundAccessStatus.AllowedWithAlwaysOnRealTimeConnectivity)
            //unregistering our old task, if there is one                   
            foreach (var task in BackgroundTaskRegistration.AllTasks)
                        if (task.Value.Name == taskName)

            //building up our new task and registering it
                    BackgroundTaskBuilder taskBuilder = new BackgroundTaskBuilder();
                    taskBuilder.Name = taskName;
                    taskBuilder.TaskEntryPoint = taskEntryPoint;
                    taskBuilder.SetTrigger(new TimeTrigger(60, false));
                    var registration = taskBuilder.Register();
        //catching all exceptions that can happen
            catch (Exception ex)
        //async method used, but wil be marked by VS to be executed synchronously
                var message = new MessageDialog("we were not able to activate the live tile. Please restart the application to try again.");
                message.Title = "Sorry,";



We are calling the BackgroundExecutionManager of Windows 8.1. This adds the Permissions dialog on the app’s first run as well as the entry in the settings charm. Only if we are allowed by the user, our tile will be updated.

Unregistering already running tasks and re-adding them is a common practice, which I did also here.

After that, I build up a new background task with the BackgroundTaskBuilder class, referencing to the taskEntryPoint I set up in the Declarations tab before.

Unlike the Windows Phone background agent, we can change the time of the background task. I used 60 minutes for this app. You will need to specify a trigger (minimum of 15 minutes). I tried it without, which lead to an exception.

I am catching all exceptions and display a message to the user here. The method will be marked as executing synchronously, but it will work. The reason is that no async methods are allowed in the catch block.

Like always, I added this to my App.xaml.cs file, as this is set up application wide. To start the task, I just call it in the Application.Launched event. It would also work in the OnWindowCreated event, if you want your Launched event free.

Setting up a background task to update your live tile with data from web is not as easy as on Windows Phone, but with this article you will be able to get started on that.

As always, I hope that this post is helpful for some of you.

Happy coding, everyone!

Posted by msicc in Archive, 1 comment

How to update a live tile in a background agent with web data on Windows Phone


In one of my recent projects, I needed to update the live tile of the app via a background agent with data from a WordPress based web site. I did what I always do when implementing a feature I never used before: researching.

I found tons of example on how to update the live tile periodically, but non of them told me how I can use the data from the web site or where I need to put it in.

In the end, it was Jay Bennet, developer of the fantatsic WPcentral Windows Phone app, who gave me the last hint I needed – where do I start the request for the data I need. Thanks to him for that!

Ok, but let’s start in the beginning. When it comes to web based services, you first need a class (or ViewModel) that can hold your data you receive from your service. I explained that already pretty well here. No matter if you are running your request within your app project or in a PCL, it pretty much always works like this.

After stripping of our class out of the JSON string, we are now able to create our request as well as our Background Agent.

The first thing you need to do is to add a Windows Phone Scheduled Task Agent. Create a new project within your app and choose the project type mentioned before. Then, in your main project, add it as a reference (right click on References/Add Reference/Solution => select your background agent project there. That’s it.

No go to your ‘ScheduledAgent.cs’ file and open it. You will find this code in there:

protected override void OnInvoke(ScheduledTask task)
  //TODO: Add code to perform your task in background


And thanks to Jay, I know that this is where all the action (not only updating the tile like in all samples I found) happens. This may sound very trivial for those of you who have experience with that, but if you’re new to it, it may hold you back a bit. However, there are a few points you’ll need to take care of:

    • you only have 25 seconds to perform all action here
    • your task will run every 30 minutes, no way to change that
    • scheduled tasks need to be restarted within 14 days after the current start
    • Battery saver and the OS/the user can deactivate the agent
    • there is a long list of what you are not able to do in here (check MSDN)
    • there are memory limits (check MSDN)

all action needs to be finished before NotifyComplete() is called

Based on this information, I created my task as following:

        protected async override void OnInvoke(ScheduledTask task)
        //performing an async request to get the JSON data string        
            PostsFetcher postfetcher = new PostsFetcher();
            Constants.latestPostsForLiveTileFromWordPressDotComResultString = await postfetcher.GetLatestPostFromWordPressDotComForLiveTileOnPhone();

        //deserialize all data
            var lifetileBaseData = JsonConvert.DeserializeObject<json_data_class_Posts.Posts>(Constants.latestPostsForLiveTileFromWordPressDotComResultString);

            Deployment.Current.Dispatcher.BeginInvoke(() =>
        //using Telerik's LiveTileHelper here
                Uri launchUri = new Uri("Mainpage.xaml", UriKind.Relative);
                RadFlipTileData fliptileData = new RadFlipTileData();
                fliptileData.BackContent = lifetileBaseData.posts[0].title;
                fliptileData.WideBackContent = lifetileBaseData.posts[0].title;
                fliptileData.BackTitle = string.Format("{0} {1}", DateTime.Now.ToShortDateString(), DateTime.Now.ToShortTimeString());
                fliptileData.Title = "LiveTileTitle";               

                if (lifetileBaseData.posts[0].featured_image != string.Empty)
                    fliptileData.BackgroundImage = new Uri(lifetileBaseData.posts[0].featured_image, UriKind.RelativeOrAbsolute);
                    fliptileData.WideBackgroundImage = new Uri(lifetileBaseData.posts[0].featured_image, UriKind.RelativeOrAbsolute);
                    fliptileData.BackBackgroundImage = new Uri("Images/BackBackground.png", UriKind.RelativeOrAbsolute);
                    fliptileData.WideBackBackgroundImage = new Uri("Images/WideBackBackground.png", UriKind.RelativeOrAbsolute);
                    fliptileData.BackgroundImage = new Uri("Images/PlaceholderBackgroundImage.png", UriKind.RelativeOrAbsolute);
                    fliptileData.WideBackgroundImage = new Uri("Images/PlaceholderWideBackgroundImage.png", UriKind.RelativeOrAbsolute);
                    fliptileData.BackBackgroundImage = new Uri("Images/BackBackground.png", UriKind.RelativeOrAbsolute);
                    fliptileData.WideBackBackgroundImage = new Uri("Images/WideBackBackground.png", UriKind.RelativeOrAbsolute);

                foreach (ShellTile tile in ShellTile.ActiveTiles)
                    LiveTileHelper.UpdateTile(tile, fliptileData);


As I fetch different data from the site, I create a class that holds all request methods. In those methods, I just created an HttpClient that downloads the desired Json string into my app. I take only the first post in the case above, to make the live tile updating also on slow internet connections within the 25 seconds and to not reach any memory limit. In the end, I use Telerik’s LiveTileHelper to create a FlipTile with image and text from the site (the image will be downloaded automatically).

That’s all we need to to in the Scheduled Task Agent. Now we need to implement the agent into our app project.

First thing we should implement is a switch where the user can turn our agent on and off. I used a ToggleSwitch for that, saving the isChecked state as a Boolean to the IsolatedStorage of my app.

Knowing I need to restart the background agent after some time, I implemented the agent handling in App.xaml.cs. This way, I need to write less code as I tend to use separate settings pages. The only thing you need to think of is to set up all objects as static and public.

First, we need to declare a PeriodicTask as well as a name for it:

public static PeriodicTask LiveTileUpdaterPeriodicTask; 
public static string LiveTileUpdaterPeriodicTaskNameString = "LiveTileUpdaterPeriodicTaskAgent";

Now we need to generate a method that handles everything for our background task:

       public static void StartLiveTileUpdaterPeriodicTaskAgent()
        //declare the task and find the already running agent
            LiveTileUpdaterPeriodicTask = ScheduledActionService.Find(LiveTileUpdaterPeriodicTaskNameString) as PeriodicTask;

            if (LiveTileUpdaterPeriodicTask != null)
        //separate method, because we need to stop the agent when the user switches the Toggle to 'Off'
                //  ScheduledActionService.Remove(App.LiveTileUpdaterPeriodicTaskNameString);
                //catch { }

        //generate a new background task 
            LiveTileUpdaterPeriodicTask = new PeriodicTask(LiveTileUpdaterPeriodicTaskNameString);

        //provide a description. if not, your agent and your app may crash without even noticing you while debugging
            LiveTileUpdaterPeriodicTask.Description = "This background agent checks every 30 minutes if there is a new blog post.";

        //start the agent and error handling
        catch (InvalidOperationException exception)
        //user deactivated or blocked the agent in phone settings/background tasks. Ask him to re-activate or unblock it
                if (exception.Message.Contains("BNS Error: The action is disabled"))
                    RadMessageBox.ShowAsync("it seems you deactivated our Background Agent for the Live Tiles. Please go to settings/background tasks to activate our app again.", "Whoops!", MessageBoxButtons.OK);

        //the maximum of running background agents is reached. No further notification to the user required, as this is handled by the OS
                if (exception.Message.Contains("BNS Error: The maximum number of ScheduledActions of this type have already been added."))
                    //changing the Boolean to false, because the OS does not allow any new taks
                    isLiveTileActivated = false;
            catch (SchedulerServiceException)
                //if there is a problem with the service, changing the Boolean to false. 
        //feel free to inform the user about the exception and provide additional info
                isLiveTileActivated = false;

In Application.Launching() and in ToggleSwitch_Checked event, call this method. In ToggleSwitch_UnChecked event, call ‘StopLiveTileUpdaterPeriodicTaskAgent()’ instead to stop the agent.

Before we are now able to debug our agent, there are two things left. The first thing is to declare


in the very first line of ‘App.xaml.cs’ as well as in ‘ScheduledAgent.cs’ before all using statements.

The second thing is adding an if-Debug command to our ‘StartLiveTileUpdaterPeriodicTaskAgent()’ and also to our ‘OnInvoke(ScheduledTask task)’ methods:

 ScheduledActionService.LaunchForTest(LiveTileUpdaterPeriodicTaskNameString, TimeSpan.FromSeconds(60));

Add this after adding the task to the SchedulerService in our agent starter and before ‘NotifyComplete()’ in ‘ScheduledAgent.cs’.

If you run the project now in Debug mode, your agent will be debugged and forced to run after 60 seconds. If you run the project in Release mode, Visual Studio will throw an ‘Access Denied’ error, so make sure you set it up correctly.

If you follow all steps above, you will be able to add a Live Tile updated via background agent very easily to your app.

As always, I hope this real world scenario will help some of you.

Until then, happy coding!

Posted by msicc in Archive, 7 comments

How to work with the user’s music library on Windows Phone


I am currently exploring a lot of APIs that I never used before  in my Windows Phone apps as I am adding more features to my NFC Toolkit.

Like I always do, I create sample applications to explore what is possible and then integrate them into my main app.

One of those APIs is the MediaLibrary class on Windows Phone. You might think: there are tons of examples out there, why another post? Well, I agree, there are a lot of samples, but I want to cover a whole scenario.

In my sample, I am getting a list of all Albums stored in Library, start them playing, and display the current playing song as well as handle state managements of the playing song.

First, you will need to add the capabilities ID_CAP_MEDIALIB_AUDIO and ID_CAP_MEDIALIB_PLAYBACK to your app. If you will not do that, every call against the APIs will end up with an NotAuthorizedException.

For any access to the MediaLibrary and the MediaPlayer classes we are using the Namespace “Microsoft.Xna.Framework.Media”. Here our trouble begins already.

Xna is Microsoft’s framework to create games on Windows Phone 7.  As Windows Phone 8 supports also native code, this is mainly used in 7 games. That’s why you might run in some TargetInvocationExceptions while you debug apps that use them.

To avoid this, we need to add a Framework Dispatcher that simulates a game loop for us. Add the following method to your App.xaml.cs:

        private void StartGameLoop()
            GameTimer gameTimer = new GameTimer();
            gameTimer.UpdateInterval = TimeSpan.FromMilliseconds(33);

            gameTimer.Update += delegate
                { }



We are starting a new GameTimer and delgate it to our UI using the FrameworkDispatcher.Update() method. By adding it to App.xaml.cs and calling this method in Lauching and Activated event of our app, we have it running through our whole app and are done with this.

There are several methods to this, I found this the most easy version. I would pay credits, but don’t remember where I saw this – sorry.

Before we came to our first call against the MediaLibrary, we need to add a class for our List<T> or ObservableCollection<T>. I don’t know if this is the best practice in this case, but it made working with the List of Albums very easy for me:

        public class AlbumFromStorage
            public string AlbumName {get; set;}

            public string AlbumArtist {get; set;}

            public WriteableBitmap AlbumCover {get; set;}

            public SongCollection AlbumSongs { get; set; }


To use this class, just add a new List<T>/ObservableCollection<T> to the Page class. Do the same for a MediaLibrary object and an AlbumCollection object:

public ObservableCollection<AlbumFromStorage> AlbumsList = new ObservableCollection<AlbumFromStorage>();
public MediaLibrary lib = new MediaLibrary();
public AlbumCollection albumslist;

Now we are prepared for fetching all local stored albums. Add the following code to your corresponding method:

            albumslist = lib.Albums;

            if (albumslist.Count != 0)
                foreach (var item in albumslist)
                    AlbumsList.Add(new AlbumFromStorage()
                        AlbumArtist = item.Artist.ToString(),
                        AlbumName = item.Name,
                        AlbumCover = PictureDecoder.DecodeJpeg(item.GetThumbnail()),
                        AlbumSongs = item.Songs

                MusicAlbumListBox.ItemsSource = AlbumsList;
                await MessageBox.Show("It seems you have not stored any music on your phone.", "Sorry :(", MessageBoxButton.OK);

Let me explain the code. First, we are using our AlbumCollection object to asign the MediaLibrary.Albums property. This will give us a collection of all albums. Then we need to check first, if the count in the collection is not 0 (it will throw ugly exceptions if a user doesn’t have any music stored if you won’t to this).

Then we add these albums to our ObservableCollection<AlbumFromStorage> picking the interesting properties of each album for us.

As the thumbnail for the album cover is a Stream, we need to use a WriteableBitmap for calling the GetThumbnail() method. The last step adds our ObservableCollection<AlbumFromStorage> as ItemSource to our ListBox.

This will be the result (based on my current albums list):


Now all we need to do is to make a tapped album playing with Windows Phone’s media Player.  Add the following code to the Listbox ItemTap Event:

             if (Microsoft.Xna.Framework.Media.MediaPlayer.State != MediaState.Playing)
                 //to delete the recent song (if there is any), just add this

                 var selectedItem = this.MusicAlbumListBox.SelectedItem as AlbumFromStorage;

                 // play the SongCollection of the selected Album
             else if (Microsoft.Xna.Framework.Media.MediaPlayer.State == MediaState.Playing)
                 MessageBox.Show("You are already playing music. Please stop the music first.");

                 //your own handling could be different here, like asking the user for the desired action and perform  it then


As you can see, I use the MediaPlayer.State property to get the album playing. The album is a SongCollection that holds all songs of the album. I recommend you to stop the last played song (if there is any) first with the MediaPlayer.Stop() method before start playing the first album song with the MediaPlayer.Play() method. Otherwise, it may happen that the user hears a second from the old song.

Very important: you must handle the case that the user has already music playing. If not, your app is likely to not pass certification.

After we started playing the music, we naturally want to display the current song.

To achieve this, we need to add two events to our page constructor: MediaPlayer.ActiveSongChanged and MediaPlayer.MediaStateChanged.

Within the MediaPlayer_MediaStateChanged event, add the following code:

            if (MediaPlayer.State == MediaState.Playing)
                var activeSong = MediaPlayer.Queue.ActiveSong;
                Dispatcher.BeginInvoke(() =>
                    MusicTileTitleBlock.Text = string.Format("playing:\n{0}\n{1}", activeSong.Name, activeSong.Artist);


            else if (MediaPlayer.State == MediaState.Paused)
                var activeSong = MediaPlayer.Queue.ActiveSong;
                Dispatcher.BeginInvoke(() =>
                    MusicTitleBlock.Text = string.Format("paused:\n{0}\n{1}", activeSong.Name, activeSong.Artist);                    
            else if (MediaPlayer.State == MediaState.Stopped)
                Dispatcher.BeginInvoke(() =>
                    MusicTitleBlock.Text = "music stopped"; 

This way, we use the MediaState to display the the current state as well as the title and artist. As we are updating the UI thread, as Dispatcher is used to update the Text.

To change the title and the artist of the current playing song, use this code within the MediaPlayer_ActiveSongChanged event:

            var activeSong = MediaPlayer.Queue.ActiveSong;
            Dispatcher.BeginInvoke(() =>
                MusicTileTitleBlock.Text = string.Format("{0}\n{1}", activeSong.Name, activeSong.Artist);


If you want to display also the album image, you will need to cache the image from the ItemTap event before, which would work fine with albums. If you choose Playlists instead of Albums, this will not work out well as you will not be able to get the image from MediaPlayer.Queue.ActiveSong.

I did a lot of research to get this feature(s) working the way they should. I took me several hours to figure everything out exactly, and I hope this post helps some of you out there to save some time on this.

With this post, you will be able to generate the whole experience your users deserve from the beginning to the end.

Until the next post, happy coding!

Posted by msicc in Archive, 1 comment

Add your app: List of uri associations for Windows Phone

While development of my NFC Toolkit, I came to the point where I needed to launch apps from my code.

On Windows Phone, this is only possible via custom uri association and needs to be implemented by the developer of an app.

If you want your app to be launchable from other apps, you need to implement a custom uri assocation like descriebed here in the MSDN Documentation.

Users are demanding often apps to be launched from other apps – it is not much work to do, so I recommend you are implementing those features into your app(s). Over time,  your app will be getting more recognition amongst users of other apps and improves the user experience a lot.

To make it easier for everyone of us, please add your app here:

Let’s make this list a basic resocurce for everyone of us!

Until then, happy coding!

Posted by msicc in Archive, 3 comments