OpenNETCF.Callbacks library is a rather powerful tool that can be used to significantly enhance the functionality of CF application. Its primary use is to allow using APIs that require the developer to provide a callback function, such as EnumWindows etc. An unexpected bonus is an ability to subclass an arbitrary window, including those behind CF intrinsic controls (Form, Textbox, Label etc). For example the only way to process Help menu item in Window CE is for the application window to handle WM_HELP message. The Form object does not provide such facility, but by subclassing the main form it is possible to intercept this message and process it, presenting user with the help page.

Download the sample here: http://www.alexfeinman.com/download.asp?doc=TabTest.zip