Hooking into Windows with C# to Produce Windows 7 New Feature

Question

I just saw a really useful UI feature of the forthcoming Windows 7 ( visit http://www.gizmodo.com.au/2008/10/windows_7_walkthrough_boot_video_and_impressions-2.html and scroll down to the video entitled Super Scientific Video of New Window Resizing Feature)

In a nutshell you can drag a window by the title bar to the top of the screen to maximise it, drag it back down to restore and drag it to the left edge or the right edge of the screen to have it snap into position butted up against the edge you dragged it to, and resized to occupy half the screen.

Now I know there are a bunch of keyboard-based apps that do "similar" things but I've not seen a mouse-based program that does JUST the above, simple, useful and nothing more. If you know of one (or are smart enough to write one) please post the URL :)

Anyway, if I wanted to try and write a small app to do this I have a question:

If I wanted to try and write a small app to do this, could I write it as a .NET app? I guess hooking into Windows' window drag/drop handling is pretty low-level and maybe not something that could be done in C#.NET?

any smartypants here who can knock a small app like this out in their lunchbreak? ;) I'm sure anything mimicing Windows 7 features would prove very popular, at least pre Windows 7's launch.

Edit: The AeroSnap guys (http://www.aerosnap.de/index_eng.htm) have done a nice job of implementing this feature and judging by the number of downloads, it was a popular feature!

Answer 1

Yes, you can do this from C#, via PInvoke. Tbh, the best way to learn such APIs is by looking at the source of something like Bblean. This'll show you what you need to know and exposing it to PInvoke is pretty trivial.

Answer 2

pinvoke.net

This is a good reference website for using the Windows API via PInvoke from within .NET applications.

Answer 3

Thanks for taking the time to answer. I'll checkout using PInvoke. I'm assuming I need to hit the Windows API for both the hooking into windows as well as actually performing the move/resizing of the dragged window?

Answer 4

If your goal is to create a hook that works across all applications and thus all windows on the desktop, then you cannot use a managed code assembly. You will have to write in a language that produces traditional DLLs such as C++.

In order to hook at the system level which then hooks into all running applications you must provide a dll that can be placed into the address spaces of all running aps. I would venture to say that a large percentage of most people's daily aps are not managed .net framework apps.

Answer 5

Try looking at these articles:

• http://www.codeproject.com/KB/system/WilsonSystemGlobalHooks.aspx (probably most useful)
• http://www.codeproject.com/KB/system/globalsystemhook.aspx (another approach yielding similar results as above)
• http://msdn.microsoft.com/en-us/magazine/cc188966.aspx (MSDN article with some oldish code but a nice explanation)

Answer 6

Try checking this one also, you have the explanation, source code and the references to the official MSDN documentation.

http://www.josefcobonnin.com/post/2007/06/19/Hook-Keyboard-and-Mouse.aspx

Answer 7

There's an offical way: Windows API Code Pack

The Windows® API Code Pack for Microsoft® .NET Framework provides a source code library that can be used to access some new Windows 7 features (and some existing features of older versions of Windows operating system) from managed code. These Windows features are not available to developers today in the .NET Framework.

The individual features supported in this version (v1.0) of the library are:

Windows 7 Taskbar Jump Lists, Icon Overlay, Progress Bar, Tabbed Thumbnails, and Thumbnail Toolbars. Windows 7 Libraries, Known Folders, non-file system containers. Windows Shell Search API support, a hierarchy of Shell Namespace entities, and Drag and Drop functionality for Shell Objects. Explorer Browser Control. Shell property system. Windows Vista and Windows 7 Common File Dialogs, including custom controls. Windows Vista and Windows 7 Task Dialogs.