Gunnar Peipman's ASP.NET blog

This blog entry is supposed to be the continuation for entry C# Extension Methods where I told what extension methods are and how to use them. This time I will tell about what they are behind the curtains. Do they really add new methods to current classes or not? I mean, are these methods really added to classes or are they something else?

Recently I had to create Web Part connection between BDC based list and usual SharePoint list. BDC list was provider and usual SharePoint list was consumer. I was pretty surprised if found out that I was able to connect BDC based list only to other BDC based Web Parts. All the other Web Parts were not able to be consumers for them. Same time BDC lists were able to be consumers of the other web parts.

One of new cool features that will be available in C# 3.0 are extension methods. Extension methods will allow us to extend existing classes with new functionality. In this example I will show you how to extend System.string with two methods that are very popular in PHP: nl2br() and md5().

C# 3.0 makes it very convenient to create properties that doesn't carry any functionalities besides returning value of attribute and assigning value to it. This new feature is called automatic properties.

Some time ago I had to deal with sorting algorithms. Besides my main task I found a good way how to test custom sorting algorithms. This blog entry is one of early birds, more about sorting algorihtms is coming soon. Hopefully some time after TechEd 2007 for Developers. The procedure I wrote to test sorting algorithms is simple and works. Of course, I am always opened for better ideas if somebody wants to suggest some. Here's the little overview about what I've done.

In this example we will use simple color recalculation method to grayscale images. For each pixel on image we will calculate "average color" that we write back on image. Average color is sum of current color's red, green and blue channels integer value divided by three. This value is assigned to all three channels for current pixel.

Lately I faced the need to search for specified strings in all stored procedures in given database. I found SQL-DMO library very useful for it. So, ten minutes later I had a simple form that fits my needs perfectly. And some minutes later I had there some more cool features. As a result I had form that enables me to search for strings from stored procedures, user defined functions and views. Also I was able to search strings from mentioned objects names. I tested it on a little bit larger MS SQL Server database, iterating approximately through 500 database objects and searching for given string and I mentioned no performance problems. So, here's the example.

At the end of the previous month I wrote a posting on DefensiveDatasource class that can be used to associate ASP.NET's GridView with collections containing objects of different types and based on one and the same base class. Dividing data into pages in GridView does, however, not succeed. An error message "The data source does not support server-side data paging" is displayed.