Dynamic Control Layout With WPF

If you are even a little bit familiar with the Model-View-View Model pattern and its implementation in WPF, you have probably run into the ItemsControl control. Actually, even if you haven’t used MVVM, you may have used it. Somewhat like the Repeater control in ASP.NET, this control allows you to bind to a data source and do something in XAML for each of the items in that data source. In any case, let’s play around with the ItemsControl element in WPF a little bit.


Selecting Multiple Rows as a Single Column in SQL

Recently, I was writing a report that selected some data out of a normalized SQL Server database. For one of the queries, I needed a “flattened” form of the rows in one of the tables. In essence, what I needed to do was turn several rows of data into a single column.


Using LINQ To Find Duplicates

I recently ran into a situation that has come up plenty of times for plenty of people. I had an array of integers and I needed to figure out if any of the numbers were in the array more than once.

A variety of solutions ran through my head: sorting, looping, searching, etc. However, LINQ seemed like the most elegant solution. Here’s what I finally settled on:

A Web Server In Less Than 100 Lines of Code

Last night at the Lincoln .NET User’s Group, we had our second laptop meeting. A few people brought some code, a dev tip, or a fully working program to demo. I choose to show my "100 Line Web Server" I created to perform some unit testing on an app that was HTTP-centric, lately.

So, here is the entire program. I hope it’s useful to some and at least interesting to most.

Using Command-line Parameters In WPF

If you need to read command-line parameters within your WPF application, your first inclination (if you are like me) might be to go looking for the Main method. Of course, you won't find a "Main" method in a WPF application. Instead, start looking at the App.xaml file.

By the way, for the rest of this post, I'll presume you will be using command line switches like the following:

Save WPF Ink Strokes To a Database

In my previous post about creating a bitmap from an InkCanvas in WPF, I mentioned that you could easily save the ink strokes for later. I wanted to post a code example for writing those strokes to a database and de-serialized them back into memory.

The first step in saving to a database is to get an array of bytes from the strokes in the InkCanvas. To do this, the StrokeCollection provides a convenient Save method:

Consuming JSON Services Without AJAX

JavaScript Object Notation (JSON) is one of the technologies used by AJAX and other "Web 2.0" technologies. It is a way to communicate in an object-oriented fashion between the web server and a client-side, JavaScript-based application. Every now and again, you might find yourself in a situation where you would need to consume a JSON service, but without a JavaScript endpoint. I ran into this situation when I needed to talk to an application that exposed a web interface, but has no other API hook. My mind first jumped to "screen scraping" the web pages in the exposed web interface. However, when I started to dive into the HTML, I found a very rich JSON service behind those pages.

An example message that I saw coming back from the application looked like this:

Convert WPF InkCanvas to Bitmap

We live in a digital age and if you are like me, paper is only used when it is absolutely unavoidable. If you have a tablet PC, signing your name to attach it to a document may be one less thing you will need a physical sheet of paper for.

The WPF ink control can be put into your XAML to collect stylus strokes as a collection of geometry points. Of course, as the stylus moves, the movements are also shown on screen.

SQL Bitwise Mask Example

.NET Binary Numbers

The following code snipit will get you all of the binary numbers from zero to fifteen: