As you may know, we recently announced the April Refresh of the Windows Phone 7 developer tools. We’ve made some changes to some our APIs, including the way our Push Notifications work.

A few things you need to be aware of with the new tools and code for Push Notifications in WP7:

1. In your WP7 application’s WMAppManifest.xml file, ensure you have listed out the capabilities that your application will be utilizing. In this case, for your application to support Push Notifications, at the least you’d need to add the following to your WMAppManifest.xml:

<Capabilities>
    <Capability Name="ID_CAP_NETWORKING" />
    <Capability Name="ID_CAP_PUSH_NOTIFICATION" />
</Capabilities>

2. Your application needs to have an entry for the publisher. Perform the following steps since the default entry for Publisher is empty by default (changes in bold and red):

   <App xmlns="" ProductID="{5286c8f1-e346-4a8b-a0c9-1b37aa9bdc9d}" Title="PushTest" RuntimeType="SilverLight"
   
   Version="1.0.0.0" Genre="NormalApp"  Author="ai" Description="pushtest" Publisher="ai">

3. There are a couple of changes in the actual payload that gets sent. Inside the application that actually posts the notification (through Microsoft’s push notification server) to Windows Phone 7, the payload now needs to look like (changes in bold and red):

   string toastMessage = "Content-Type: text/xml\r\nX-WindowsPhone-Target: toast\r\n\r\n" +
   
   "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +

   "<wp:Notification xmlns:wp=\"WPNotification\">" +

   "<wp:Toast>" +

   "<wp:Text1><string></wp:Text1>" +

   "</wp:Toast>" + "</wp:Notification>";

   I’ve used an example payload for a Toast Notification above, but similar changes apply for other types of notifications.

That’s it! I’ve tested this with the ‘Push Tweets’ sample app:

Related articles:

1. Changes in the April release of the Windows Phone 7 developer tools
2. MSDN: Send a Push Notification for Windows Phone 7
3. Push tweets to a Windows Phone 7 device (via push notifications)
4. Windows Phone Developer Tools CTP Refresh

@ai

[Update: The source code for the app is now available on Codeplex: http://4square.codeplex.com]

Foursquare is one of the leading location aware applications out there today with a rapidly growing user base. They’re really hot right now – they exploded dramatically at SXSW this year. We take it for granted when things “just work” – I can’t recall Foursquare having any kind of downtime at SXSW in spite of the explosive usage they saw that week and this is a huge testament to their dev team that managed the required scale so well.

Some of you may have seen the Foursquare Windows Phone 7 app that was demo’d on stage at MIX last week. The app looks amazing and “critics agree” ;)

Here’s what the app looks like. For your information, it’s around 11.10pm right now on March 24, 2010, and I’m at my hotel, the Las Vegas Hilton in Las Vegas, NV for CTIA Spring.

Now this is something that’s a little different from what you may have seen before. You can see where your nearby friends are on a map. I’ll be honest with you – it was till I was using the Foursquare app on Windows Phone 7 when I first got to Vegas that I new Brett Petersel was in Vegas for CTIA. I happened to notice another pushpin on the map, clicked on it, and it was him.

Tonight he happens to be at the Benihana which is near the Hilton:

At MIX, I’d put out a teaser about the ‘Society’ tab within the app. Now, some time back, the Foursquare team told me about their firehose. I asked Naveen Selvadurai about a practical use of the firehose within a mobile app, and his response: “that’s your job! ;)” So I thought to myself – when I’m at an event, like CTIA, what I want to know is where it’s going down right now. Where are people checking in right now? So here’s how we use the foursquare firehose within the WP7 Foursquare app.

Clicking on the Society tab, takes me to this screen:

The number of checkins is a real-time view of checkins that have been accumulated in the past few minutes. Panning around on the map a little bit to see where the action is tonight:

Just a few minutes later, I refreshed the map again. I guess Aria’s the place to be at tonight (at least right now):

This application was written in C# and Silverlight and is an example of how we can push the boundaries of user experience and consuming real-time data within a Windows Phone 7 app. You like?

@ai

PS: Talk about Foursquare exploding, I saw this in the Las Vegas Hilton:

Some time back the team and I talked about our commitment to the Silverlight and XNA platforms on Windows Phone 7 Series as the primary developer platforms. We also promised to go into more detail about these platforms at MIX.

Not to oversimplify things, but, you can think about creating an application using the following iterative process:

While I can’t help you a whole lot with the ideation, I want to drill into a little more detail about how you can Design, Develop and Test your app, and eventually Distribute and Monetize your Windows Phone 7 app. The easiest way to think about how to design and develop for Windows Phone 7 Series is to break it down in to the platform piece and the tools piece.

The Platform

Silverlight and XNA

As we’d mentioned earlier, the primary development platforms will comprise exclusively of Silverlight and XNA. The Silverlight platform will be a superset of Silverlight 3 with some specific APIs and features that cater to the phone. The .NET Compact Framework, as we know it today, will not be exposed in Windows Phone 7 Series.

Location and Push Notification Services

The need to get a device user’s current pinpoint location has become increasingly important to mobile application developers. We’ll be exposing APIs for developers to get a user’s current location. The API in turn will use a variety of techniques, including GPS, Cell Tower Information (where possible) and WiFi based lookup (where possible).

Developers also want to be able to asynchronously send information down to devices that have their applications installed. This is typically information pertinent to an application and the services they expose (like informing a user asynchronously that a friend may have posted something on their Facebook wall, for example). To enable this scenario easily, we have the Push Notification Service, a mechanism for sending information over HTTP directly to the phone, regardless of whether or not the application is running. This information in turn can be used to send notifications to the user in the form of a ‘toast’ or by updating a live tile on the start screen.

Example of a Live Tile

Hardware Design Specification

One of the biggest questions I keep getting is about the type of Windows Phone 7 devices that will be hitting the market. This is obviously a sensitive area for developers – the software looks great, what can I expect from the hardware?

There is a single Windows Phone 7 Series hardware specification – hardware manufacturers will use this specification as a baseline to build devices that will run Windows Phone Operating System 7.0. Developers can count on the fact that all Windows Phone 7 Series hardware will include

• a powerful processor,
• 256 MB of RAM with a minimum of 4 GB Flash,
• 802.11 b/g wireless,
• capacitive only screen,
• 5 sensors – A-GPS, accelerometer, compass, proximity and light, and,
• two options for kinds of screens; WVGA at launch and HVGA coming shortly thereafter.

The Tools

With previous versions of Windows Mobile, there were a myriad of issues with trying to acquire the right tools including things like the cost of actually acquiring the tools itself, localization issues, performance (of the emulators) and many more. Charlie Kindel, the developer platform lead, and Drew Lytle, lead program manager on the developer platform, talk about how they wanted the tooling to be “friction free” – easy to acquire, easy to install, easy to get developing.

You can head over to the http://developer.windowsphone.com portal and download a free tool, called the Windows Phone Developer Tools Preview, that will bring down the requisite pieces for you to able to developer for Windows Phone 7 Series. This download is about 3MBs big. These requisite pieces are also free and will include:

• Preview of Visual Studio 2010 Express for Windows Phone if you do not have Visual Studio 2010 installed, Windows Phone 7 Series Add-in for Visual Studio 2010 if you have Visual Studio 2010 installed
• XNA Game Studio 4.0
• Windows Phone 7 Series Emulator

Designers are a crucial piece to our application development story. Especially since Silverlight is one of the key developer platforms on board, we want to enable designers to be able to do their jobs well. Expression Blend is a tool that helps designers design Silverlight based applications. Today, we have a preview of Expression Blend 4 for Windows Phone available which is also free. Christian Schormann is the authority on our team on Expression Blend – be sure to read his blog post on Expression Blend 4.

All that said, now imagine being able to use Expression Blend to design your applications, Visual Studio to complete the development and being able to create a sweet Windows Phone application that you can easily test on a highly performant emulator. *drool*

Visual Studio 2010 Express for Windows Phone

Windows Phone 7 Emulator

Distribute and Monetize

Once you’re done designing, developing and testing, you want to be able to distribute your application and possibly monetize. There are two components to this piece, one is the developer portal where you can submit your applications, the other the Windows Phone Marketplace client that will help you acquire applications from your device and/or your computer. The Windows Phone Marketplace will be the exclusive way to download apps to your Windows Phone 7 Series device (we will provide avenues for developers to ‘unlock’ their phones for testing purposes). We will furnish information on submitting applications to the Marketplace at a later time.

On the device, the Windows Phone Marketplace is it’s own hub. The layout is beautiful, and it will help consumers discover apps and games easily. There are also hooks to discover relevant applications through other hubs, like being able to find a music application from the Music and Videos hub, for example.

One of the key features that have been added to this implementation has been the ability for developers to programmatically support a trial mode within their application. This way consumers have the option of trying before they buy an app. Developers will also be able to ‘deep link’ to the applications they have developed and furnished on the Marketplace from their own website, thereby making it easier for consumers to download apps.

And, students who are registered for Dreamspark can register on the Windows Phone Marketplace and submit up to two applications for free.

Ideate, Design + Develop + Test Today

• We have a bunch of resources going live to help you get going. Your one stop shop to get all the required content is http://developer.windowsphone.com
• Charlie Kindel’s post: The Right MIX
• Charles Petzold is working on the first ever Windows Phone 7 Series development book, titled “Programming Windows Phone 7 Series”. An e-book will be made available shortly – stay tuned.
• I want to constantly highlight applications that you are developing for Windows Phone 7 Series both on my blog as well as the Windows Team Developer Blog. So, let me know once you have an app cookin’.
• Tim Heuer’s post: Getting Started with Silverlight and Windows Phone 7 development
• Michael Klucher’s post: Windows Phone Developer Tools + XNA Game Studio 4.0 Available Now!
• Christian Schormann’s post: Introducing Blend 4 – For Silverlight, WPF and Windows Phone
• Be sure to follow our developer team @wp7dev, or individually, Charlie Kindel (@ckindel), Shawn Hargreaves (@shawnhargreaves) , Michael Klucher (@kluch), Andre Vrignaud (@ozymandias), Loke Uei Tan (@lokeuei) and Christian Schormann (@cschormann).

@ai

now playing in my head: Steve Ballmer screaming “Phone Developers” (a la the Marionette Windows Phone 7 Series app)