MsgHookX is an ActiveX DLL that allows VB6 developers to perform safe and efficient intra-applicaton subclassing. (In this context, intra-application sublclassing means that you can intercept any message that Windows sends to a window or a control in the current application, as opposed to a window created by another application, a much more difficult task.) I wrote this DLL many years ago, when VB5 was released, and mentioned it in several books and magazine articles. I made the DLL available on the vb2themax site, but I omitted to upload the DLL in this new, .NET-only site.

Well, given the many mails I continue to receive from readers, it seems that VB6 is still alive and in good shape, and many VB6 developers continune to happily subclass their controls. For this reason I decided to make the DLL available again on this site. Here's a summary of what it does:

• safe subclassing: can be used within the IDE and in break mode without any risk of system crashes.
• it provides the BeforeMessage and AfterMessage events for easy event-driven programming model
• it additionally can notify incoming messages through the IMsgHookEvents secondary interface, for better performance and easier debugging (in some cases, events are inhibited in the IDE)
• highest flexibility: you can decide to call the original window procedure yourself from within the BeforeMessage event/method and/or cancel the default processing for the message. You can also browse and modify the value that will be returned to the operating system.
• the DLL's type library includes the definition of over 300 symbolic constants that define the most common Windows messages, so you don't have to use the API Viewer to include them in your applications.

Have fun with it, but - please, please! - turn to VB.NET as soon as you can, if you haven't yet.