Paneque's Technology Blog

Unable to start the process. Failed to initialize CoreCLR, HRESULT: 0x80131500 I just installed ASP.NET Core RC2 and was able to get it working from the command line, on some new basic tests projects. But when I tried to do it from Visual Studio I got the following error.  If I tried to run "dotnet" in a console opened from Visual Studio, I would get the same error. So the issue was that something was off for the VS configuration/environment.  After verifying that "dotnet" was able to run perfectly everywhere else I took into the task of comparing the environment variables (dichotomically, of course). One particular variable made the difference: "JUSTMOCK_INSTANCE=XXXXX", so that lead me to notice that JustMock was interfering with it somehow.  So, if you use JustMock just turn it off for RC2 projects. (No need to uninstall it, just disable the profiler)

Since we got the magic of async/await on C# things got much easier on the developer front. Working with Tasks is the key to it, but we also have two older approaches in .NET framework that we need to deal with.  APM (Asynchronous Programming Model) The pair of Being / End methods.  EAP (Event-based Asynchronous Programming) The Method Async / Method Completed pair. Converting from APM to Tasks is achieved by means of the   System.Threading.Tasks.TaskFactory   class and its generic counterpart. Now converting from EAP to Tasks  requires us to use the TaskCompletionSource<T> class and notify of the state of the task as it goes. See the example of a "handshake" operation in a WCF service. I am also using the approach from my older post regarding events and anonymous methods. The return type of the WCF operation is WrappedResultOfString , and that will be the actual generic parameter of the Task<T> that the HandshakeAsync method will produce. publi

Did you ever have a problem with a WCF client throwing exceptions you can't catch? If you have used WCF clients from Windows Phone, Silverlight or Xamarin.iOS, you might have noticed that it is not possible to create Synchronous or Task-Based operations; the functionality is reduced to the Event-based Asynchronous Pattern (EAP). That means that the way to call a WCF method and get the response is usually as follows: var client = new MyWCFClient(); client.DownloadDataCompleted += (sender, e) => { try { //accessing e.Result here might raise an exception in another //thread, that will not be captured by the 'catch' below. } catch(Exception ex) { } }; client.DownloadDataAsync(url); Our results are wrapped in an auto-generated class that inherits from  AsyncCompletedEventArgs , this class has a property  Error  of type  Exception , that will carry information about the error and a property  Result  with our expected return value. Accessing th

Batch as usual Recently I was in the need of modifying a huge amount of files across a network share. After installing Serviio media streaming service I noticed that it will crash "randomly". After checking the logs it was clear that ffmpeg was crashing when trying to open subtitle files that were not in the encoding indicated by the Serviio console. I needed a quick way to update all subtitle files to a common encoding, so I decided to convert all files to UTF8. Since I use a windows environment I went directly to PowerShell and wrote this.  Get-ChildItem -path .\ -filter *.srt -file  | ForEach-Object { (get-content $_.FullName) | Out-File $_.FullName -encoding utf8 } This worked almost right except for files with "[" or "]" (among other symbols) on the name or path. To solve it, just added the "-LiteralPath" switch to tell powershell not to consider any wildcards on the path name and just use it exactly as it is.  Get-ChildIt

In addition to pizza, caffeine, and video games, a developer requires a lot of tools, and I mean "a lot". Each one is different so here I want to showcase what I use, and briefly explain why. The idea of this post rather than make any type of advertising (notice there are no links at all) is more to actually find out what other people use and share with you all my experience. So, the profile:  .NET Developer. The usual work: Web applications with ASP.NET (Web Forms and MVC) Windows Forms Windows Presentation Foundation Windows Phone Apps iOS Apps  Of course, I might code almost every day a bit of JavaScript and some HTML/CSS fixes, along with some other things, but that's not enough to consider it the main course. The Infrastructure Before coding, organization and planning is everything, and that means for me 3 things, since I am a SCRUManiac: Source Control Issue/Bug tracking Continuous Integration For source control, I prefer Git particularly,

One the first entry of this series I covered the issues with the keyboard in iOS not hiding automatically when needed. In this second - and final - entry on the subject I am going to go for the most of annoying issue when creating UIs in iOS. The keyboard overlaps a focused TextField  If you have a TextField below the keyboard top edge position, they will be hidden once the keyboard shows up. The keyboard size is 320x216 points* in in portrait mode, so anything below the 264 (iPhone 4/4s) or 352 (iPhone 5/5s) points won’t be visible.  It is so simple that is almost unbelievable, but it happens as you can see in the images. Since this default behavior is inconvenient we are going for the workaround. The solution is not pretty but it is trivial: we need to place the UI elements inside a UIScrollView  and will use notifications to monitor when the keyboard will Show/Hide and will scroll the content of the container to ensure that views inside are always visible. We are u

When you are a developer for more than one platform, you might find that what is considered basic or pre-built in one, it’s incomplete or completely missing in another one. This entry is about fixing some issues with the virtual keyboard on iOS; especially when it hides your text fields or keeps the input focus. Xamarin Studio/Mono and XCode were used for this example. Hiding the keyboard Tapping inside the TextField will show the keyboard, but it won't be possible to get rid of it by tapping outside or pressing “RETURN” on it. This is something pre-built in Silverlight for Windows Phone. Tapping outside of the textbox or hitting the “back” key will hide the keyboard. But well, there is no back key on the iPhone. So let’s start by creating and extension method that we will use in the rest of the solution. The method will return the view that is the first responder or the “active” one. public static class Extensions { public static UIView FirstRespon

Time ago I wrote an article  about the comparison between of HTML5 and Silverlight. That article was indeed about the "comparison" itself rather than another attempt to compare the two; mainly because I consider that kind of measuring to be pointless. Then again with the pass of time the same question arises: is Silverlight dead? Before going into trying to answer that, allow me to be clearer than what I was at the time and let me rephrase the question: is the silverlight plugin for browsers dead? Well... the answer is yes, not even a "maybe". But as with any existing software, dead is not actually extinct. We still have people writing code in COBOL, FORTRAN,  DELPHI and VB6. And this is because the enterprise market does not move at the same pace as the consumer market. They invest in infrastructure, they keep it, and they treasure it. And Silverlight was highly adopted in the enterprise for LOB applications. So in that area, Silverlight is going to be there

Popular wisdom says "things happen for a reason". However experience has proved me that when it comes to programmers, that is not always true. Things can just happen for no reason at all. That's why we require feedback, here is one and I assure you is in good spirit. So let's me write about something I found when building an app for iOS using Xamarin/Mono. The invisible property. Ranging from windows forms (desktop or Windows Mobile) to WPF, Silverlight/XAML on the web or windows phone. ASP.NET Web Forms or Razor, MVC or classic. One thing I can say for sure: any visual element  has a way to check for its visual status. Call it "Visible" in windows forms, "Visibility" in Silverlight/WPF. There is always an intuitive, simple and trivial way to know if something - that might be visible - it is visible at a particular moment or not. You can't imagine my surprise when I realized that the UIViewController in iOS does not provide such mecha

I have published apps and games for Microsoft Windows Phone, and I update them in a regular basis. Most of the time is because a bug is found, sometimes is a new feature or just because I am trying something new. It helps to keep things moving and people thank you for that. However, I never had to protect an app or a game from human stupidity. Until now . Software developers learn  over time how to deal with the final user - in some measure - and I must admit is not easy; as programmers we are not trained to deal with them, is usually another person's job. But when it comes to phone/tablet apps, that individual is you, because as an 'indie' developer you are too close to the complete production line. I classify the users like this: The happy mute The unhappy mute The fan The hater The stupid The mute ones... There are always people that either like or don't like your app or website, or tool, but they just don't say anything. This is good and b

This is  the second and final part of this series. Will focus now a bit on what happen when we add multithreading to our work with events. Cleaning Up Events and Context Information In the previous post I mentioned some issues using lambdas and anonymous methods on events. The unsubscribe problem had a tricky "solution" by declaring a "cleanup" method inside the class that holds the event. public void CleanupSubscribers() { SayHelloCompleted = null; } The problem here is obvious since the cleanup method will remove all subscribers from the event. Hence, individually removing listeners from the event gets tricky when using lambdas/anonymous methods. So in this case the recommendations would be: Do not use lambdas if you need to unsubscribe. If you do so, use the cleanup method UNLESS your code is multithreaded.  NOTE: this only applies to the use of lambda expressions and anonymous methods, as for regular named methods you can always r

Combining lambdas, anonymous methods and events feels natural in C#, and we use them almost as a reflex, they help us to create closures and avoid creating state variables outside the scope of our methods or passing extra state data through event calls. But one thing that come with events is the fact that writing good applications implies making good use of the resources, meaning we have to dispose those we no longer need. When using events with lambdas and anonymous methods, is possible to forget about that, thus writing code that is not efficient and prone to crashes. Will start this 2-part series talking about the subscribe/unsubscribe behavior. Subscribe/Unsubscribe lambdas and anonymous methods Let's begin with a basic scenario using events in a single-thread context for now; just to keep it simple. The code fragment below contains the HelloEventArgs implementation as well as the publisher class MyClassWithEvents . public class HelloEventArgs:EventArgs {

Few days ago I added a new App to my inventory on Windows Phone Marketplace. The Loan Calculator app was just something I needed when I was in a hunt for a car (still am). The thing is I wanted to keep it simple. Just input the numbers and see the total, how much, for how long, you know.. just the FINAL number. Which is what car dealers will never give upfront, because they always play that 101 psychology thing on you. So I built this app using the common formula that you can see around in many websites. The idea is pretty simple, just input the data and get the total final price and the monthly installments. As an extra you can also see how the amortization for the loan plays along time. Check it out, assume we want to calculate the final price for a car that cost 25k, we will put a  10% down payment, 2.5k, with an APR of 3.0%, and with a loan term of 3 years. Just enter the data and hit "Calculate" Then we just get the summary result with the final cost, se

Well, initially I might get upset, but only if they break something. But here I am not talking a team member changing your code... No... that's OK This blog entry is about that 'non-deterministic' behavior that sometimes happens to 'us' while developing software and all of the sudden something does not work as it 'should' be. Who does not hate that kind of bugs right? This example is a real case scenario using Telerik components in a web application. Consider the following piece of ASPX code, I have placed a button and a label, the button 's click event in code-behind event will change the value of the label. Pretty simple right? Just a button with a javascript confirmation dialog before performing the page's post back. Now lets 'ajaxify' this... Using the new ajaxified code now have pretty much same effect, except we are not performing a full page post back, but only updating elements inside the UpdatePanel control. But what if I

When deploying and testing websites that use secure connections (SSL)  we might get warnings about non secure content on the page. This is usually an easy thing to fix. Just find a tool like "Fiddler" and find out what traffic is going over a regular HTTP (non secure) channel. Sometimes even a simple FIND over the code will let you find those "unsecured" elements. But that's not enough if you refer some javascript or refer a link over SSL that then does some non-SSL redirection.  Each browser has a similar way to show you how secure you are on a website. Google Chrome shows website security indicators (icons) that will appear next to your site URL in the toolbar. The first one (1) is just a regular site with no SSL, and we want number (2) the green one, you should avoid the other ones. Now two notes on that. Google Ads Don't use Google Adsense on your website if you use SSL and you care about your site not showing any warning, the ads will b

Sometimes you get so used to do something everyday that you don't appreciate how much time it saves you. So in this entry I want to go back to the basics and comment on something I had been asked many times. I remember the times where we used Active Sync to connect Windows Mobile devices, is was not that hard but it could get tricky some times, depending if the device was connected via USB or Wi-Fi, emulators via  DMA and more. And to be honest, it was not that long ago. Fortunately the new Microsoft Windows Phone 7 series does this in a pretty easy way. Zune Besides being used to download apps, musics, podcasts or to sync content between the computer and the device. The Zune software is what we can easily use to "hook up" your device with your Visual Studio and deploy apps to your phone. If you are a registered developer at Microsoft Marketplace just connect your unlocked/activated phone. Run Zune if not setup to auto-start. Then on the Visual Studio just  select

A bit of time ago I published an app called Hidden Pics on the Microsoft Marketplace, on that entry I covered some basics on the Isolated Storage and the PhotoChooserTask for Windows Phone 7. On this entry I want to cover the zooming and panning. As part of that app, the user has the option to open a photo full size on the device screen and then pinch to zoom the photo.  They can also pan by dragging on the screen with the fingers. Now this is supposed to be very basic, but there is a catch, which is making the zoom stable. By stable I mean that if you use two fingers to zoom in the photo, once you finish the two fingers should have the same pixels behind them, which indicates that you zoomed proportionally and panned correctly. After googling around a bit I put together the code to do both zooming and panning properly. So here is the XAML for the control, I am using an Image control inside a Canvas with a CompositeTransform : The photo will start fully fitted on the Image c

Just days ago I finished and published my first app to Microsoft Windows Phone Marketplace. As part of the "#30tolaunch" program, I must admit that waiting for  the app to be certified was a little scaring, but the app was approved without any trouble and is already up, you can grab it here . Now the idea of the app is simple, it uses the Isolated Storage to hide pictures you want to keep out of curious people looking at your phone. And it involves two common elements that might be useful for you in future apps. 1) Isolated Storage 2) Photo Chooser Task Isolated Storage. The Isolated Storage is a virtualized file system so your app can't really access the device storage like it used to be. If you are a Windows Mobile developer, you might remember those times where you could write/read files all across the filesystem of a windows device. Thankfully that's not like that anymore. And you get a isolated space just for you application. Reading bytes from a file

App is the new black, everyone talks about downloading, buying or selling apps, advertising about them is everywhere. The phone manufacturers have marketplaces and stores where phone users can get get those "apps". We all know the term app is short from application. If this term was coined because was easier or because of a marketing strategy I don't know. But it is catchy, and so we will use it. But to be exact on term, int this case it means "mobile application". Otherwise any program would be an app right? But exactly what is an "app",  really ?  Third-party programs running on mobile is not something new at all, for  more than 10 years we had Java Midlets for almost any kind of cell phone, and I myself programmed for years for the Pocket PC and Windows Mobile, using either eVC, eVB, and later any .NET language like C# or VB.NET by using the .NET Compact Framework (.NET CF). And all those were actually apps . So, if is not new, why the boom

As a general rule, I always use some kind of source control on all my projects. For the matter of fact I use GIT even when some people might find that weird, being myself a .NET developer .... But hey... GIT is in my opinion the best things out there when it comes to really good team development tools. Then the second part is to use it with people online, for that github.com is pretty good, and the final part is a good add-in for Visual Studio or a shell extension. I use Git-Extensions for all that and so far, except for the little problem I am going to explain here, I have no complains at all. The problem: Git branches are case-sensitive, so you can have "test" and "TEST" as different branches, and it will work fine if you use linux as a client. But when using git-extensions from Windows, and ran into a huge problem, where one of my friends was pushing code and I was not able to see it. She was uploading code to same branch but just with different casing. Is