If you bind a grid to a large data set, you will inevitably create a control larger than is comfortable to show on the screen. By default, if you have this the root view model in Caliburn Micro, you will end up with a window that is so large that it is hard to manipulate on the screen. This is because, by default, the windows that CM creates are set to size to the control. If you want to change this behaviour, you will need to change the SizeToContent property of the window to Manual. To do this, you need to do the following:
First, you need a custom window manager. If you’re using an IoC container, you can simply register an implementation of IWindowManager. I recommend subclassing the default WindowManager class. If not, you can simply override GetInstance in the Bootstrapper; this also has to advantage of suppressing annoying on-boot exceptions.
Secondly, override EnsureWindow (as of 1.1, it’s slightly different in 1.0) in the window manager. You’ll note the window manager is aware of the view model it contains, which allows for more customized approaches depending on your requirements. A final gotcha: whereas most of the code is found in the Silverlight implementation, WindowManager is completely different between WP7, WPF and Silverlight and is contained in different projects.
Colour Coding 