When the Host is not so Perfect

Here is something that has recently bit me really bad. Customer requirements called for implementing an in-house report designer to create report definitions. Expired by the VS.NET 2005 Report Designer, we decided to implement a part of the tool as a WYSWYG designer using the design-time infrastructure (IDesignerHost) in .NET 2.0. If you don’t know what I am talking about, read the excellent Dinesh Chandnani’s Perfect Host article to learn more about the .NET designer host support.

To spice up the user experience, we decided to use the Infragistics Windows Forms suite. At runtime, the end user could drag Infragistics UltraTextBox and UltraImage controls and drop them on the design canvas. Everything was working just fine during development (aka my machine). However, once the application was deployed to QA, the WYSWYG designer failed abysmally. After some digging, we realized that the Infragistics controls was performing the same license check as they do when dropped on a Windows Form in VS.NET 2005. Since the Infragistics controls fail to find a design-time license, they throw an exception once the user attempts to site the control and there wasn’t any workaround. We had no other choice but to yank out the Infragistics controls and replace them with the plain-vanilla Windows controls – TextBox and PictureBox.

The moral of this story is to avoid using third-party controls when implementing .NET custom designers to prevent licensing gotchas.