Search results for C# - ThinqLinq by ThinqLinq


Roslyn resources

Today I’m giving a hand’s on hack session on using Roslyn to create code Diagnostics. As part of that, I put together a listing of some resources that might be helpful and thought I’d share them with everyone. Realize that these links are based on the versions for the Visual Studio 2015 RC and are subject to change when the product releases. With that in mind, here are the links: Download Visual Studio versions: Github repository for the Roslyn compilers: http

ThinqLinq Samples on Github

When I first created this site, I used it both as a test bed for technologies as I played with them and as a repository for others to use for my presentations and other insights. Over the years people have been free to grab these samples, but haven’t had good ways of giving back to help improve the samples. In the mean time, there have been quite a number of technology changes. While I may have been late to the party on some, there’s only so many things one can focus on. One of the advances we’

Reactive Extensions RX in Action the movie

I’ve been giving presentations for some time now. By far, my favorite talk to give is my Reactive Extensions in Action. This past summer, I had the talk recorded at the Code on the Beach conference. If you haven’t had a chance to see it live, now’s your chance. The focus of this talk is to focus on some of the practical uses of Rx rather than the underpinnings of how it works. I hope you enjoy and this sparks ideas from you on how you can use it in your applications. Rx in Action recorded at C

Left Outer Joins in LINQ with Entity Framework

As I spend more time reviewing code with clients and on public forums, I’m constantly seeing cases where people have issues with Outer joins in LINQ and the various flavors of LINQ. In this post, I’m going to look at a couple options from a syntax perspective that you can use to make working with outer joins easier with LINQ. Naturally, we have a much deeper discussion of outer joins in our book that you’re welcome to dig into as well. Typically, if you do a join in LINQ, it will perform an inne

CodeLens for Visual Studio 2013 configuration

One of the new features of Visual Studio is the ability to automatically see statistics about your code while you are looking at it via a new feature called CodeLens. For example, you can see how many method calls are referencing your method, how many bugs and what tests are accessing the method. While this information can be helpful when reviewing code, it sometimes gets in the way when writing it. For example, you can’t just click the 0 references line and start adding attributes and comments

Rx for Windows Phone article now available

A couple of years ago I gave a presentation at the last MIX for doing asynchronous programming using Reactive Extensions (Rx) on the Windows Phone. The video of the presentation is still available for watching. Around the same time, I was approached by Code Magazine to write a similar article, which I was happy to oblige. It took a while but I was happy to see the article finally published in the Sep/Oct 2013 edition of Code Magazine. In the article I demonstrate how to use Rx to build a dice r

Async in loops

In yesterday’s post, I mentioned that there is a performance penalty of using the new Async/Await feature inside of loops. Today, I want to point out another reason why you might not want to use Async/Await inside of a loop. Consider the following example that takes a web page as a string and finds all of the hyperlinks contained in that page (using a regular expression match) and downloads each of those child pages. Using Tasks from the TPL we can load the child pages like this: private vo

Rx samples with WinRT

Recently I decided to rebuild one of my presentation computers using the Windows 8 Consumer Preview and Visual Studio 11 Beta. While it is working quite well for my typical usage, I did run into a bit of an issue when prepping my Rx talks for the Rocky Mountain Trifecta this past weekend. In the past, when I'm giving my Practical Rx talk, I show Silverlight, WPF, WP7 and RxJs samples. Unfortunately, the Windows 8 Consumer Preview does not support the Windows Phone 7 emulator and Visual St

Select Many with Rx and RxJs

A while back, I showed how you could use the query syntax and Rx to code a drag-drop operation similar to the way you might describe  the process to your mother. As a review, let’s take another look at the code, this time in C# as a preparation for moving it over to javaScript. var mouseDown = from evt in Observable.FromEventPattern<MouseButtonEventArgs>(image, "MouseLeftButtonDown") select evt.EventArgs.GetPosition(image); var mouseUp = Observable.FromE

devLINK RxJs and Async session materials available

I would like to thank everyone who came out to my DevLINQ sessions this week. The materials for both of the sessions are not available on the Files tab  of this site. In addition, here are the descriptions and direct links to each of these downloads: Reactive Extensions for JavaScript (RxJs) The Reactive Extensions allow developers to build composabile, asynchronous event driven methods over observable collections. In web applications, you can use this same model in client si

Does LINQ to SQL eliminate the possibility of SQL Injection

By default, LINQ to SQL uses parameterized queries rather than concatenated strings when executing your LINQ queries. As a result, if a user tries to perform SQL Injection by improperly escaping parts of the SQL, the escape is considered part of the parameter rather than part of the query and thus avoids the injection. However, as we discussed in chapter 8 of LINQ in Action, LINQ to SQL greatly reduces the possibility of SQL Injection, but doesn't completely eliminate it. For example, if you a

Dynamic Programming in a Statically Typed World

Tomorrow night, I’m giving my presentation discussing not only how, but when to consider using the dynamic features of C# 4 and VB (forever). If you attend the presentation, you can download the samples and slides from my download page. Part of the key in this presentation is  discussing the Why as compared to the simpler How of Dynamic. Here are some of my top reasons to use the dynamic features: Testability When trying to use unit testing, the compiler often limits the ability to follow

Rx Mock Accelerometer using Observable.GenerateWithTime

When people ask about resources to learn how to use Rx on the Windows Phone, I often point them to the How to guides, including the How to: Use Reactive Extensions to Emulate and Filter Accelerometer Data for Windows Phone. Unfortunately, I have a problem with the underlying implementation of the emulation method which returns values through an iterator (yield) and IEnumerable<T> and then cast the IEnumerable to IObservable. As I pointed out in a MSDN forum post, It would be better to reco

Using LINQPad with MongoDb and NoRM

I’ve recently been working on a project that might be a good fit for the rising wave of Document Databases espoused by the rising NoSQL movement. Unlike the traditional Relational Databases like SQL Server, Document Databases can store object hierarchies, or unshaped data for quick and efficient saving and retrieval. There are quite a number of these databases appearing, including MongoDb, CouchDb, RavenDb. Wikipedia also has a listing of Document Databases with links to other options. Typicall

Visual Studio 2010 Keyboard Binding Poster

When I work with new teams, I often get asked how I did x using the keyboard instead of reaching for the mouse. I find if I can keep my hands on the keyboard, I can often be much more productive. So, how do you learn to take advantage of the keyboard shortcuts, I recommend downloading one of the Key binding posters like the ones that were just released for Visual Studio 2010. The posters are available for VB.Net, C#, F#, and C++. Once you have then downloaded, pick a  a different key bind

Replace Foreach with LINQ

One of the best ways to start Thinqing in LINQ is to find places where you can replace iterative loops with LINQ queries. This won’t necessarily make your applications any faster at the moment, but by taking advantage of the declarative syntax, it will allow you to change your underlying implementation (ie. parallelize it with PLINQ) easier in the future. Recently, I came across some code that mimicked creating a control array as we used to have in VB6 by iterating over a list of fields and addi

LINQ to CSV using DynamicObject

When we wrote LINQ in Action we included a sample of how to simply query against a CSV file using the following LINQ query: From line In File.ReadAllLines(“books.csv”) Where Not Line.StartsWith(“#”) Let parts = line.Split(“,”c) Select Isbn = parts(0), Title = parts(1), Publisher = parts(3) While this code does make dealing with CSV easier, it would be nicer if we could refer to our columns as if they were properties where the property name came from the header row in the CSV file,

Using Cast Or OfType Methods

When working with generic lists, often you want to work with a more specific type than the list natively exposes. Consider the following where Lions, Tigers and Bears derive from Circus Animal: Dim items As New List(Of Object) items.Add(New Lion) items.Add(New Tiger) items.Add(New Bear) Dim res1 = items.Cast(Of CircusAnimal)() Dim res2 = items.OfType(Of CircusAnimal)() In this case, both res1 and res2 will return an enumerable of CircusAnimal objects rather than jus

Watch language differences when parsing Expression Trees

I’ve run into a number of cases where people have built LINQ providers and only tested them with C# clients. In one case, I was sitting next to the person who wrote the provider when we discovered that using a VB client didn’t work with their provider because they failed to test it. I’ve even seen it in the sample Entity Framework provider  available on the MSDN Code Gallery when parsing the .Include() method. Hopefully, you will be able to access my VB translation of the EF sample provid

Iterators OR Excuse me waiter theres a goto in my C sharp

At Codestock '09, I gave my LINQ Internals talk and had a number of people express shock when I showed the underlying implementation of their beloved iterators when looking at the code through Reflector. Let's look first at the C# that we wrote. This is similar to the implementation of LINQ to Object's Where method as shown in the sequence.cs file that's part of the C# Samples. public static IEnumerable Where(this QueryableString source, Func predicate) { foreach (char curChar in source)

LINQ In Action Samples available in LINQPad

I've been asked for some time what I think about the LINQPad tool. For those of you unfamiliar with it, LINQPad is a small but powerful tool that allows you to test your LINQ queries along with other VB and C# code. With this tool, you insert your code snippets in the code window and run it directly. If you point it to a database connection, LINQPad will build the .DBML behind the scenes and let you access the generated classes just as you would inside visual studio. When you execute the code, y

LINQ to SQL support for POCO

One of the strengths that LINQ to SQL has over the upcoming Entity Framework is its support for POCO, or Plain Old Class Objects. With LINQ to SQL, the framework doesn't require any particular base classes, interfaces or even reliance on the 3.5 framework for the resulting objects. I demonstrated this in the talk I did at the Teched Tweener weekend. Download the demo project to see this in action. In this sample, I created two separate projects. The first class library project, I created only t

LINQ enabled Personal Web Starter Kit in C Sharp

I love it when projects take a life of their own. A while back, I posted my LINQ enabled Personal Web Starter Kit in VB and received several requests to provide a C# port. Thankfully, one brave soul stepped up and did the port for me. Thanks go to Stephen Murray for undertaking the challenge. As is often the case, one of the best ways to learn a technology is to use it. If you're interested in this sample, you can check out the project at the MSDN code center. Specifically, you can access the

Consuming a DataReader with LINQ

Last night at the Atlanta MS Pros meeting, I gave the first my new talks on LINQ Migration Strategies. If you missed it, you can catch me at the Raleigh, NC and Huntsville, AL code camps. Baring that, check out the presentation slides. This talk focuses on how you can extend existing structures using the power of LINQ. Among other things, this includes LINQ to DataSets and the XML Bridge classes. During the presentation, fellow MVP, Keith Rome asked a question that I couldn't let sit. Is it pos

LINQ to SQL Compiled Queries

As LINQ nears release, people are starting to consider the performance implications that the extra overhead brings. Currently there are two threads on this: thread1, thread2. For those that are intested in the performance implications, I highly recommend checking out the outstanding series of posts by Rico Mariani. Ultimately if you want to get the best performance, you need to use the Compile function of the CompiledQuery class. Let's consider the following query (Note, turn this into C# by a

Auto Implemented Properties

I was looking over the help documentation included as part of the March Orcas CTP which I recently downloaded. I noticed that most of the documentation that came with the previous previews appears to have not made it into this release yet. If you want documentation and samples telling you what LINQ is all about, I still recommend grabbing the MAY CTP which you can find from my LINQ Links post a while back. If you prefer, soon you will be able to catch a book on LINQ I'm helping out on. Check out

Extension Methods are powerful and dangerous

Much of the querying functionality present in LINQ and the associated techologies leverage a new language feature known as Extension methods. With an extension method you can "extend" any type simply by adding the "this" keyword before the first parameter of the method definition. The LINQ samples primiarly extend IEnumerable<T>. However Extension methods can be used to extend any type. Perhaps the following sample class can help explain the Extension method. In this e