If you have had a chance to play with Visual Studio Whidbey, you may have noticed some of the cool new features in the Forms designer - snap lines, smart tags and so on. Now what if you desire to expose some of this design time UI in your own application? Guess what, Whidbey makes this super easy to do! As I will show below, with less than 10 lines of code, you can display a form that hosts the Windows Forms designer.

The designer classes you will need are located in the various System.*.Design namespaces, particularly System.ComponentModel.Design. These are part of System.Design.dll, so you will first need to add a reference to this assembly (that ships as part of the .NET Framework SDK).

The first thing you need to do is create a DesignSurface. This is the class that represents the user interface that you would think of as the “designer”.

DesignSurface surface = new DesignSurface();

There, now we have a DesignSurface. Next, we need to indicate what the type of the root component is, and ask the DesignSurface to load it. We want a Form designer, so:

surface.BeginLoad(typeof(Form));

BeginLoad begins the process of loading the designer, and will continue asynchronously. However, the “view” that represents the root component at design time is immediately available after this call.

Control view = (Control) surface.View;

Cool, now we have a Control that represents the View. We can manipulate this Control just like any other Windows Forms Control. In this case, lets dock fill it and add it to a Form.

view.Dock = DockStyle.Fill;
Form myDesigner = new Form();
myDesigner.Controls.Add(view);
myDesigner.Show();

That's it! You now have a form hosting the Windows Forms designer, complete with support for snap lines, smart tags etc! Ofcourse, to create a little more functional designer, you need to provide a way to add components to the Form, set properties etc. You may also need to implement a couple of designer services along the way. But the 7 lines of code above are all you need to get started!