This is one of those “D’oh!” moments.  You’re creating your own UITypeEditor.  You know the UITypeEditor class is located in the System.Drawing.Design namespace.  So naturally you want to add to your Visual Studio project a reference to the System.Drawing.Design.dll, right?  Wrong!  When you compile your project, the following error may appear: The type or namespace name Related posts: Adding Assemblies to the Visual Studio "Add Reference" Dialog Web Service Stumper: “Ambiguous Type” IEventHandlerService Already Exists in the Service Container

The .NET FolderBrowserDialog class does not have an InitialDirectory property like the OpenFileDialog class.  But fortunately, it’s quite easy to set an initial folder in the FolderBrowserDialog: FolderBrowserDialog dialog = new FolderBrowserDialog(); dialog.RootFolder = Environment.SpecialFolder.Desktop; dialog.SelectedPath = @"C:Program Files"; if (dialog.ShowDialog() == DialogResult.OK) { Console.WriteLine( dialog.SelectedPath ); } Note that you can choose other RootFolder’s like MyComputer and MyDocuments.  Related posts: Adding Assemblies to the Visual Studio "Add Reference" Dialog Console Output from a WinForms Application The Proper Way to Show the Wait Cursor

As developers, we all make assumptions when programming. Perhaps the biggest assumption we make is that those libraries and tools that ship with the .NET Framework are the best way to accomplish a given task. For example, most developers assume that using ASP.NET’s Membership system is the best way to manage user accounts in a website (rather than rolling your own user account store). Similarly, creating a Web Reference to communicate with a web service generates markup that auto-creates a proxy class , which handles the low-level details of invoking the web service, serializing parameters, and so on.

If you encounter this warning while compiling a Windows Form application in Visual Studio: The service System.Windows.Forms.Design.IEventHandlerService already exists in the service container. Parameter name: serviceType The solution is not very obvious, and the help provides no guidance.  After a little experimenting, I discovered an easy solution: Exit Visual Studio. Open Explorer, and navigate to the folder Related posts: Visual Studio 2008 and .NET 3.5 Service Pack 1 Released Adding Assemblies to the Visual Studio "Add Reference" Dialog Web Service Stumper: “Ambiguous Type”