I am trying to determine if C# has the capabilities to listen for system
events when the application does not have the window's focus.

I am writing a windows application that I would like to run in the
background when I am using my computer. I would like this windows
application to utilize the clipboard, and determine when data has changed on
the clipboard. I would also like my app to listen for Ctrl+C and Ctrl+V
events, as well as mouse copy/paste events.

What I have be able to explore so far is that I can write an app that will
listen for keyboard events when the application has window's focus. I cannot
seem to find any information on if it is possible to listen to events when
the window does not have focus.

Can anyone provide insight to help me out? Preferably C# code if it's
possible. Is this solution possible with the C# language?

Thanks,

Alex

Hi Yanhong,

I believe that Alex should implement Global Hook instead of the one
associated to a specific thread. However, Microsoft .NET Framework does not
support Global Hook. That is, we are not able to use C# to implement it.
The KB article 318804 discusses this issue in detail:

HOW TO: Set a Windows Hook in Visual C# .NET
http://support.microsoft.com/?kbid=318804

"You cannot implement global hooks in Microsoft .NET Framework. To install
a global hook, a hook must have a native dynamic-link library (DLL) export
to inject itself in another process that requires a valid, consistent
function to call into. This requires a DLL export, which .NET Framework
does not support. Managed code has no concept of a consistent value for a
function pointer because these function pointers are proxies that are built
dynamically."

Have a nice day!

Regards,

HuangTM
Microsoft Online Partner Support
MCSE/MCSD

Get Secure! ¨C www.microsoft.com/security
This posting is provided ¡°as is¡± with no warranties and confers no rights.

Hi Alex,

You can do this in C# but you have to use the Win32 API. The
SetClipboardViewer() function can be used to register your application for
notifications of clipboard changes.

I have an article and an example in C# on my site that goes into more
detail.

http://www.radsoftware.com.au/web/CodeZone

--
Ross Donald
http://www.radsoftware.com.au/web/WebLog/

"Alex" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I am trying to determine if C# has the capabilities to listen for system
> events when the application does not have the window's focus.
>
> I am writing a windows application that I would like to run in the
> background when I am using my computer. I would like this windows
> application to utilize the clipboard, and determine when data has changed
on
> the clipboard. I would also like my app to listen for Ctrl+C and Ctrl+V
> events, as well as mouse copy/paste events.
>
> What I have be able to explore so far is that I can write an app that will
> listen for keyboard events when the application has window's focus. I
cannot
> seem to find any information on if it is possible to listen to events when
> the window does not have focus.
>
> Can anyone provide insight to help me out? Preferably C# code if it's
> possible. Is this solution possible with the C# language?
>
> Thanks,
>
> Alex
>
>