Reflection IT Blog

Together with Jan Tielens, I have created a improved version of my User Control Container Web Part called the SmartPart for SharePoint.

Jan has written an introduction and even created a video demonstrating it in action.

We have created a GotDotNet Workspace for the SmartPart. Over there you can download an installation package that will install the SmartPart, the source code and an example user control. At this point there isn’t very much documentation, but I will work on that. :-) There are a lot of cool ideas which (I hope) will be added to the SmartPart (for example a connectable SmartPart). I’ve IM-ed with Patrick today and he has another cool idea which he discussed in one of his latest posts: using the User Interface Process block together with web parts. Anyway, some nice ideas are waiting to be implemented!

The PageUtil class has a static method SetInitialFocus(control) which can be used to generate a JavaScript for an ASP.NET page (WebForm), which sets the focus on a (given) control.

        private voidPage_Load(objectsender, System.EventArgs e)
        {
            // Set the InitialFocus on TextBox1
            ReflectionIT.Web.PageUtil.SetInitialFocus(TextBox1);
        }

TextBox1: 

It took me today some time to figure out how to sort an array of strings case-sensitively. The default behavior of the Array.Sort() uses an default Comparer object which should be case-sensitive. When I tested this I found out that I had misinterpreted the definition of 'case-sensitive'. What I wanted was 'Oridinal' sorting. So I created an OrdinalStringComparer class which implements IComparer and I got what I wanted.

And when you run this program you get the following output:

SharePoint is a great product. In this article I will demonstrate this by creating a Web Part which acts like a container for normal ASP.NET User Controls (.ascx files). This makes it very easy to customize a portal page by adding normal ASP.NET User Controls to it.

This table gives you an overview of all collections in the System.Collections and System.Collections.Specialized namespaces.

Read also Jan Tielens article on the MSDN Belux website.

I have used the EventsHelper class to fire events asynchronical. I came across this class in the TechEd 2003 presentation C# Best Practices from Eric Gunnerson and Juval Löwy. Today I noticed a bug. The FireAsync() method uses the 'Fire and Forget' pattern incorrectly.

The 'Fire and Forget' pattern is used when the return value and returned parameters of the call are not required, and when there is no need to synchronize with the asynchronously executing method. In this case, the caller simply needs to call BeginInvoke, passing any normal and ref parameters, and null for the callback and asyncState.

This has been a commonly used pattern. However, there has been a documentation change in version 1.1 of the .NET Framework that has big ramifications for this technique of making async calls. The documentation now states that EndInvoke must be called for a corresponding BeginInvoke--otherwise Microsoft say they may now, or in the future, leak resources. It appears that no resources are leaked under version 1.0 of the framework; however, with this type of warning in place, it is recommended that a call to EndInvoke be made even if the return values of an async call are not required.

It is relatively straightforward to create a helper class that handles this for you--one example I found here.

I have written the following DateDiff() function in C#. VB.NET users already had it using the Micrsoft.VisualBasic.dll assembly. Now you can use it without referencing this 'ugly' extra assembly.