Hacking .NET and Startups

Announcing XAPFest – A Massive Windows Phone 7 Hackathon in Santa Monica, CA on June 4th 2011

xapfest_black_logoI am pleased to announce something very exciting that Microsoft is doing in my neighborhood of Santa Monica, California: we’re putting together XAPFest, a massive Windows Phone 7 hackathon aimed to bring together startups and mobile developers of all skill levels for a day of creativity and competition.

XAPFest is going down on Saturday, June 4th at the Loews Santa Monica Beach Hotel (directions) – doors open at 9:00am and will close at approximately 10:00pm. There will be opportunities for individuals and teams of developers to win prizes, eat great food, and have fun hacking down by the beach.

XAPFest is free to attend, and anyone can register for XAPFest if they wish to participate.

So here’s the full scoop behind XAPFest.

XAPFest Rules & Conditions

Your goal as a XAPFest participant is to produce a Windows Phone 7 application in a 80-90% complete state by 6:00pm on Saturday, June 4th at the Loews Santa Monica Beach Hotel (see the full schedule and driving directions.)

Here are the rules:

  1. You can get started early, and we ENCOURAGE you to get started before June 4th; install the tools and create a project on XAPFest.com and begin working on your app ASAP.
  2. You can work either as an individual or on a team of up the three people.
  3. Any apps you submit for consideration must not be in the marketplace prior to June 4th (new apps only!)
  4. In order to claim a prize, your app has to be accepted into the Windows Phone 7 marketplace shortly after XAPFest.
  5. You can submit multiple apps in XAPFest, but a team can only claim one prize in total.


Install the free Windows Phone 7 development tools early, create an app project, invite your friends, and write updates / post screenshots for your apps often!

If you have any questions about the event or want to know how to get involved (beyond registering and attending XAPFest,) please contact me and I’ll be in touch!

Otherwise, see you on June 4th!

P.S. Take a look at the apps I've created for XAPFest:

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Geolocation Services and Bing Maps in Windows Phone 7

Tonight I gave a brief talk to WinMo LA about using Geolocation Services and Bing Maps on Windows Phone 7. I mostly covered the APIs and controls that developers can use in the current Windows Phone SDK, the steps developers need to take in order to protect a user's data, and some of the future things that are changing in Mango for Windows Phone 7 developers.

Source Code for Demos:

  1. Bing Maps WP7 Demo [Github]
  2. Geolocation WP7 Demo [Github]

Other Important Links

  1. Bing Maps Portal - Get API Keys for Bing Maps
  2. MIX11 Sessions - Get all of the updates on Mango and WP7.
  3. WinMo LA - Subscribe for the next event!
  4. Windows Phone Dev Podcast - Unofficial Podcast for Windows Phone 7

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Having Network Connectivity Issues with the Windows Phone 7 Emulator?

April 7, 2011 18:07 by Aaronontheweb in Windows Phone 7 // Tags: , // Comments (0)

I spent about three hours banging my head against the wall trying to figure out why my browser could connect to the Internet but the Windows Phone 7 emulator couldn’t, and if you find yourself in the same boat as me I thought I would spare you the trouble.

Are you seeing something like this when you try to pull up a web page in IE on the emulator?


If that’s the case, then you’re having network connectivity issues specific to the Windows Phone 7 emulator. There’s a guide to troubleshooting Windows Phone 7 emulator issues on MSDN, and it speaks to the root of the issue: your HTTP proxy settings.

If you’re like me, you like using Fiddler for testing network I/O when you’re trying to connect to RESTful services – Fiddler acts as a proxy and disrupts all network I/O from the emulator; leave it turned off while you’re working with the Windows Phone 7 emulator.

Thought I’d spare any other Fiddler / Windows Phone 7 using developers the trouble Smile with tongue out

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How to Create a Twitter @Anywhere ActionFilter in ASP.NET MVC

My newest project, Captain Obvious, got a fair amount of attention this week when it landed on the front page of Hacker News – one of the key features that makes the first version of Captain Obvious tick is Twitter @Anywhere integration.

Twitter @Anywhere is brand new and there isn’t much developer documentation for it – the way to think about Twitter @Anywhere is as a Javascript platform that allows you to outsource user authentication and registration to Twitter’s servers, and in exchange you get less hassle but also less intimate access to your user’s accounts.

One of the key features to integrating Twitter @Anywhere users with your ASP.NET MVC site is reading the cookie that Twitter sets after users have authenticated – this cookie contains two parts:

  1. The Twitter user’s unique ID, an integer representing their unique account (because remember – Twitter users can change their handles!)
  2. A SHA1 hash of the Twitter user’s unique ID + your application’s consumer secret – you use this to verify that the cookie was set by Twitter, since they’re the only ones who know your consumer secret other than you.

Naturally, if you are going to use this cookie as your authentication mechanism, then you are going to need to write your own Authorize attribute that allows you to validate the content’s of the Twitter @Anywhere cookie. Here’s the source code I use for doing that:



/// <summary>
    /// Controller Action Filter Attribute which requires that
    /// </summary>
    public class ValidTwitterAnywhereAttribute : AuthorizeAttribute
        protected override bool AuthorizeCore(HttpContextBase httpContext)
            var twitterCookieValue = httpContext.Request.Cookies["twitter_anywhere_identity"];
            var consumerSecret = ConfigurationManager.AppSettings["TwitterConsumerSecret"];

            return TwitterAuthHelper.ValidateTwitterCookie(twitterCookieValue, consumerSecret);


Here’s the relevant source code from the TwitterAuthHelper that I use to actually validate the hash in the cookie:



 public static bool VerifyTwitterUser(string twitterCookieValue, string ConsumerSecret)
            var results = twitterCookieValue.Split(':');
            var sha1 = new SHA1CryptoServiceProvider();
            var hash = BitConverter.ToString(sha1.ComputeHash(Encoding.UTF8.GetBytes(results[0] + ConsumerSecret)))
                        .ToLower().Replace("-", "");
            if (hash.Equals(results[1]))
                return true;

            return false;

I’m using this code in production and it works great – all you have to do to use it is decorate your controller methods with the [ValidTwitterAnywhere] attribute and it will behave just like Forms authentication if you have that enabled in your ASP.NET MVC app.

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8 Lessons Learned from Startup Weekend

I imagewanted to post this the morning after Startup Weekend Los Angeles concluded in late February, but due to the fact that I along with half my team (Minboxed) came down with the flu the following morning, I postponed this for long than I would have liked.

Startup Weekend Los Angeles stands out among other Startup Weekends in that each one of these events have produced real companies like Vol.ly, Foodme, Ming.ly, and Zaarly – who took first place in this very Startup Weekend and recently closed a $1m dollar round of funding and soft-launched at SXSW (great job, guys!)

The quality bar for talent is high and the judges are terrific – this year we were even treated to a surprise visit from Ashton Kutcher and Demi Moore, who judged my presentation along with 9 others.

This marked my third startup weekend, my second as a participant, and my first as a team lead.

I learn something new at each Startup Weekend; the ultimate value in these events isn’t really producing a product or a company – it’s learning how to work alongside a team of strangers to build something that didn’t exist 56 hours prior.

In that vein, I thought I would share what I learned.

1. You don’t need a functional product demo to win Startup Weekend

If I can point to one thing that I personally did wrong in this event, it was over-emphasis on building a functional prototype at the detriment of everything else. I can’t help it – I’m an engineer and a passionate geek.

I spent all of Saturday hammering out a prototype, figuring out how to connect to Gmail, how to use IMAP, how to write SQL queries to score achievements, how to batch everything from an ASP.NET MVC app on AppHarbor without worker roles, and so forth…

Minboxed didn’t place in the top three at the end of the judging, despite solid engineering and design efforts from our team – another startup, Eventify.me won 2nd place however.

In the course of Eventify.me’s demo of their live product, their entire thing came down and the team leader was forced to scramble onstage for the duration of her presentation. It’s the sort of nightmare scenario that every presenter worries about. In the end, it didn’t matter though – the judges were able to appreciate the quality of the idea and the future of the business without having to see it fully in action.

2. Sell the judges on the business, not the product

We were very focused on making Minboxed an awesome product – competitive social gaming built on top of email in order to make it more fun to be productive with your email. We had some innovative monetization strategies (in my opinion) and a good general strategy for acquiring customers; in other words, I think we made a good case for building a healthy business.

However, in our pitch to the judges those aspects of our work received a fraction of the attention that our product demo and our value proposition did. In hindsight, we made a great product pitch at the cost of a great business pitch.

3. Relate your business model to a proven one

In past Startup Weekends I’ve attended, the winners have always been companies who’ve modified a successful business model to either address a new problem or a new market; Zaarly took the Craigslist model and flipped it on its head, making it demand-driven instead of supply-driven. Hinty, the winner from the previous Startup Weekend LA, took a consumer-facing twist on TellMe’s business model.

I don’t want to make it sound like Startup Weekend judges punish innovative business models – it’s just easier to sell them on something that builds on the success of something else. I still can’t think of anybody who’s built a business doing something close to what Minboxed does; maybe that means it’s a bad fit for Startup Weekend or perhaps it means that we simply needed to go further to prove that there was a viable business behind it.

4. Talk to customers early

We did not talk to customers, a huge mistake. We talked to users, people who would be playing the Minboxed game, but not people who would be paying for it.

Had we talked to customers earlier we would have discovered just how far we needed to go in terms of privacy (one of the judges told me later that this was a big part of the reason why we didn’t make it.) In addition to discovering potential issues early and helping teams pivot on their business models and products, early customer commitments and testimonials are one of the best ways to sell judges on the future of your business.

We were focused on users of products, not customers of our business – a big mistake.

5. Do your pitch presentation with someone who isn’t on your team

Small lesson here – there were a number of things we did to make a good case for Minboxed, but we didn’t touch on them with either enough clarity or enough detail to convince the judges. Had we given our presentation to someone who wasn’t on our team before we ever showed it to the judges, we could have heard their “I don’t understand why…” questions and modified it earlier.

At the end of the day, your idea will be judged by how you communicate it as it will be on its own merits, if not more. Your team will take a myopic view of the business if you don’t include feedback from outsiders, thus why this lesson is important.

6. Cap the number of team members and pick people with specific skills

This is one thing that we did really, really well. We had a team of six, which is still a little large, but we made sure that we had the right people on it. Two engineers, one designer, and three marketing / business development folks.

I had to turn away a few people, and I’m glad that I did – when you get too many people, you spend too much time trying to make sure that everyone is included and trying to roll everybody’s work into the final product / presentation. You’re better off being mean on Friday night and saying “no thanks, we’re good” and paring down your team to the bare essentials.

7. Keep the engineering workflow tight

One problem I have yet to find a good solution to is how to manage the engineering workflow for product development at Startup Weekend.

Following my experience from this past Startup Weekend, it’s my new belief that if you have an appropriately tractable idea for Startup Weekend you should have two engineers: a back-end developer who owns 100% of the database + stack and a front-end developer who implements the JavaScript, CSS, and user-experience implementation. The two engineers and the designer (if there is one) need to hammer out on-paper designs for every page with a user interaction, and the back-end developer needs to create a set of dummy controllers for the front-end developer to build against.

I say this because my teammates and I have spent a lot of time trying to merge divergent bottom-up designs on Sunday on two different Startup Weekends, instead continuing to work on the product, and it’s a major productivity-killer.

If you have better ideas on how to do this and what’s worked for you historically, please leave a comment. I don’t have a perfect system for this.

8. As a team lead, your job is to evangelize

The team lead for any Startup Weekend project is usually going to be the person who pitched the idea before it was selected; as a team lead, your first job is to evangelize a vision to your team from the first second to the last.

If your teammates have a clear vision that they can buy into, it makes it easy for them to self-manage and work with minimal interruption.

Next are your potential customers –evangelize them on the idea and get early commitments and testimonials.

Last are your judges – your job is to evangelize them on the total vision for your team, business, vision, and product and earn their votes.

Stepping away to work on the product and talk to potential customers is still time well-spent, but ultimately your first priority is evangelism.

Thoughts for next time

I’m going to participate in the next Startup Weekend LA, and I’ll pitch a new idea, and even if I don’t win I’ll learn something new. Looking forward to it!

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ASP.NET MVC3 / Razor: How to Get Just the Uri for an Action Method

March 15, 2011 17:43 by Aaronontheweb in ASP.NET // Tags: , , // Comments (0)

I normally wouldn’t post something this small to my blog, but this issue bothered me so much when I was working on some Twitter @Anywhere + jQuery integration in ASP.NET MVC3 that I couldn’t help but share it.

Issue: You’re using ASP.NET MVC3 and want to be able to place a relative Uri for one of your ASP.NET MVC controller’s action methods in a block of JavaScript or anywhere else, and you want to be able to do it without having to parse it out of an Html.ActionLink output or anything else. What built-in helper method do you use?

Solution: The answer is that you use the Url.Action method, which yields a relative Uri, as you’d expect.

Observe the code below:

	authComplete: function (user) {
		// triggered when auth completed successfully
		$.post('@Url.Action("AnywhereTest", "Auth")');

And here’s the output to go along with it:

	authComplete: function (user) {
		// triggered when auth completed successfully

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Quick and Dirty Feed Parser 1.0 Released!

January 19, 2011 19:42 by Aaronontheweb in QDFeedParser // Tags: , , // Comments (4)

Without further adieu, it’s my pleasure to announce that the full 1.0 release of Quick and Dirty Feed Parser is now available to download on Codeplex.

Here are the main reasons why you should care about Quick and Dirty Feed Parser 1.01:

  1. Works on Windows Phone 7 and Silverlight 4;
  2. All IFeed objects now consume substantially less memory on average;
  3. All IFeed objects are now serializable;
  4. All IFeedFactory objects now support DI for injecting your own feed parsers; and
  5. Added an IsolatedStorageFeedFactory for working with RSS / Atom feeds in IS for all Silverlight and Windows Phone 7 developers.

Making QD Feed Parser run on Windows Phone 7 took some work – I had to rewrite the entire parsing library using LINQ-to-XML instead of XPath, but it was well worth it. The LINQ parser is now used by default in all IFeedFactory instances, but you can inject your own if you have a better way of parsing RSS or Atom.

I’ve had the pleasure of using Quick and Dirty Feed Parser 1.0 in Geeky Reads and in my new budding project, JSONify, and QD Feed Parser has performed excellently in its response time in both of those services thus far.

I’m also building a line of Windows Phone 7 applications on top of Quick and Dirty Feed Parser 1.0, and it’s made life rather easy for me in the scheme of things.

You can read the full release notes for Quick and Dirty Feed Parser 1.01 on CodePlex, and by all means please feel free to leave me feedback here if you’ve had a chance to try the project yourself.

Contributors Wanted!

We’re actively looking for contributors who want to help make Quick and Dirty Feed Parser even better. If you’re interested, feel free to ping me via CodePlex or leave a comment below!

Update: Quick and Dirty Feed Parser Added to NuGet

Quick and Dirty Feed Parser is now available on NuGet! http://nuget.codeplex.com/

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What Drives a Startup Founder?

January 18, 2011 13:21 by Aaronontheweb in Startup // Tags: // Comments (6)

I’ve been working on numerous projects since the year began, and on Sunday night I finally got around to watching The Social Network. My expectation was that the movie was going to be a breathless attempt by Hollywood to insert themselves in something cool and relevant, a tin-eared paean to their own importance. “Hey, we can be part of the social media revolution too – check out this awesome movie we made!”

But I was wrong – the movie was excellent. I assume that aside from some specific numbers regarding equity and valuation that the movie is a pretty accurate depiction of the early years of Facebook. I don’t know Mark, but from the movie I gathered that he was a socially challenged person who was very, very focused on getting one thing done.

What Drives Me

The image that gripped me most from The Social Network was the scene where Mark and the early Facebook engineering team were living together in a small house in Palo Alto, hammering out code and taking ziplines into the swimming pool. I thought “that’s what an adventure looks like – this is what being in a startup should be all about.”

The biggest thing that attracts me to startups is the desire to be a part of a great team and the sense of shared accomplishment and camaraderie that comes along with it. I tried going it fully alone in my last startup because I simply couldn’t wait to find the right teammates any longer, and I just wanted to give it a try. It didn’t work – lesson learned.

I’ve had countless ideas, some of which I’ve tried to implement, but up until I joined Microsoft I was never on a team where everyone really gave a shit and pulled their own weight. My friends in high school and in college talked a lot of game, but no one ever stepped up with me to try to actually accomplish something. So that’s why that particular scene reached me – everyone gave a shit and did the requisite work to prove it.

Not-giving-a-shit is a disease; it corrupts morale and ruins companies. I’ve been in situations where I came into something full of ideas, energy, and effort to match, but was quickly ruined by the malcontent spirits known as don’t-give-a-shitters. If you find yourself surrounded by these types – get out before they spread the infection to you and waste your life.

I’m motivated by working with an effective team of people who want to achieve a common end. I don’t know what truly motivates Mark Zuckerberg, but my best guess is that he’s motivated by the experience of realizing a specific vision for Facebook: to map the college social experience online.

I found the whole experience of watching The Social Network to be deeply motivating - realizing an idea and doing it with the right people is better than all of the wealth in the world, and it's a hell of a lot better than making millions in the stock market. The movie made me want to be a better programmer; take more risks; find more potential teammates; and do it sooner rather than later.

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Getting Started with AppHarbor – Heroku for .NET

January 14, 2011 12:53 by Aaronontheweb in ASP.NET, Startup // Tags: , , , , , // Comments (5)

I’ve a lot of friends who are proficient Rails developers, many of whom who have left .NET for Rails.

The one piece of consistent feedback that I hear back from them is that it’s the frictionless Ruby-on-Rails ecosystem that is so attractive; moreso than the Ruby language or the Rails framework itself (although they like that too.)

Heroku, above all others, is hailed as a step forward in developer productivity and easy web application hosting and deployment.

Platform-as-a-Service (PaaS), which is what Heroku provides to Rails developers, is powerful because it eliminates much of the need to manage and maintain infrastructure. Instead of managing a number of virtual machines on a service like EC2, you manage a number of application instances or some other such abstraction. PaaS combined with a continuous build / deployment system is a powerful combination indeed and allows for unparalleled productivity for agile web developers and startups.

.NET developers have had PaaS available to them for a couple of years in the form Windows Azure, but Azure is really meant to service the needs of rapidly growing services and cloud applications, not brand new projects that have no users yet.

AppHarbor fills two needs that are unmet by Azure – it makes it easy (and currently, free) for .NET developers to have access to a Git-enabled continuous development environment, something which our friends on Rails have had for a long time, and it supports the sorts of rapid build / test / deploy workflow that is common among agile groups and startups in particular.

This, in my opinion, makes AppHarbor the perfect starting place in the lifecycle for any new ASP.NET or WCF project.

Here’s how easy it is to get started with AppHarbor using their early beta interface:

Create a new ASP.NET project in Visual Studio


I’m using ASP.NET MVC3 here, which Microsoft just released-to-market yesterday. It’s great if you haven’t used it yet. You can download and install ASP.NET MVC3 here.

Initialize a new Git repository and commit the app


I use Git Extensions for Visual Studio to manage staging / commits, and it also includes the Git bash for Windows. I highly recommend it.



Now you’re all set for your initial deployment on AppHarbor.

Create a new application on AppHarbor


Follow the instructions for adding AppHarbor as a remote to your Git repository




Check the build status on AppHarbor


and then check out the app itself: http://appharbor-demo.apphb.com/ 

If you want to see a more substantial project on AppHarbor, check out Geeky Reads.

That’s all there is to it – it’s a matter of seconds to push and deploy new builds, and thanks to Git’s commit model, it’s effortless to rollback to previous builds. Compare this experience to the pain of doing a traditional web-deploy on a shared host or pushing a solution onto Azure – this is much simpler and faster.

AppHarbor can also hook a unit test project and use the success / fail of those to determine whether or not your build can be deployed, even if it is built successfully.



Want an AppHarbor invite?

If you’re interested in trying out AppHarbor yourself, click here to create a new AppHarbor account courtesy of the special invite code on this link. The AppHarbor team is eager for early adopters and feedback, so by all means please try it out and share your thoughts and experiences with them.

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6 Really Useful Windows Phone 7 Articles

I’m in the midst of working on a line of related Windows Phone 7 MVVM Light applications which are all built on the upcoming release of Quick and Dirty Feed Parser, which includes Silverlight and Windows Phone 7 support.

I found the following articles to be really useful in the course of trying to smooth out some performance problems, implement local caching, and are just generally good links to have around if you’re trying to do any serious WP7 development:

  1. Performance of Windows Phone 7 Applications – if you’re wondering why your UI seems sluggish, then you need to read this article. It explains how to use built-in tools to enable basic performance monitoring and has a great list of fixes for common performance problems.
  2. Using Isolated Storage on Windows Phone 7 – provides a great learn-by-example overview of how you can use IsolatedStorage in Windows Phone 7 to perform simple reads, writes, and serialization operations.
  3. How to Access Packaged XML Files in Silverlight – if you ever find yourself struggling to figure out how to access XML files that you package with your Silverlight or Windows Phone 7 application, the techniques illustrated in this article should provide some illumination. It’s not as easy or intuitive as it is in ASP.NET or WPF development, but it works nonetheless.
  4. Rapid Repository 2.0 – If you’re looking for a great local db to use in Windows Phone 7, Rapid Repository might be right for you. It’s simple and easy to use, but it’s mandatory Guid-only-key policy was a deal-breaker for me. Still, compared to some of the other engines I tried, it’s one of the more well-designed local database implementations I’ve used.
  5. Passing Parameters With Behaviors In MVVM Light for Windows Phone – Great article which explains how to use commanding in MVVM Light. I use EventToCommand everywhere in my MVVM Light applications, so this was a helpful resource for me – the code sample in particular.
  6. Add/RemoveRange Methods for ObservableCollection in Silverlight - This article solved a major UI performance problem for me; the technique of supressing property notification changes for bulk modifications to lists resulted in a pretty drastic performance improvement. I'll be doing a follow-up post on this myself.

Let me know in the comments if there are any great Windows Phone 7 links that you’ve used recently that are worth sharing!

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My name is Aaron, I'm an entrepreneur and a .NET developer who develops web, cloud, and mobile applications.

I left Microsoft recently to start my own company, MarkedUp - we provide analytics for desktop developers, focusing initially on Windows 8 developers.

You can find me on Twitter or on Github!

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