Covering Startbar with a floating window, Topmost of all Topmost, andoverriding WndProc - C#

  • Thread starter Thread starter jhow
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jhow

I'm writing a dictionary application in C#, similar to Trancreative's
Word Book.

Most of these dictionary apps have a concept of a "Word Picker", which
is a small floating window that stays Topmost even when other
applications are in the foreground. The idea is that, if you are using
a web browser for example, you simply highlight a word in the browser,
click on the Word Picker window, and it will automatically search for
this word for you in your dictionary application.

I have three problems with this:

1) I would like my Word Picker window to be able to cover the Start
Bar. This works ok with the correct Form properties set, but when the
user changes the foreground app, the Start Bar appears to refresh, and
sets itself to Topmost, thus covering my Word Picker. How can I avoid
this happening?

2) This problem is related to the first problem. How do I make my Word
Picker the Topmost of all Topmost windows even if it is deactivated.
Is it possible to always claim this No. 1 spot in the Z-order,
regardless of other applications that might want to bump me off the
top?

3) In order to "pick" the word off for example, the web browser, I
want to:
a) intercept the activate message my Picker Window receives when
it is clicked
b) examine the message to determine the last activated window
c) send this last activated window a WM_COPY message to determine
which word the user has just highlighted.

The problem here is that WndProc can't be overridden in the CF. I've
read up on the MessageWindow but figured out I can't use this to
capture my Word Picker Messages. The alternative is a several hundred
lines of code from the MS CF team blog, but I don't have the time and
energy to implement this. It also seems like an awfully long work
around for a very simple problem.

Can someone suggest a simpler way of doing this?

Thanks in advance.
 
I'm writing a dictionary application in C#, similar to Trancreative's
Word Book.

Most of these dictionary apps have a concept of a "Word Picker", which
is a small floating window that stays Topmost even when other
applications are in the foreground. The idea is that, if you are using
a web browser for example, you simply highlight a word in the browser,
click on the Word Picker window, and it will automatically search for
this word for you in your dictionary application.

I have three problems with this:

1) I would like my Word Picker window to be able to cover the Start
Bar. This works ok with the correct Form properties set, but when the
user changes the foreground app, the Start Bar appears to refresh, and
sets itself to Topmost, thus covering my Word Picker. How can I avoid
this happening?

2) This problem is related to the first problem. How do I make my Word
Picker the Topmost of all Topmost windows even if it is deactivated.
Is it possible to always claim this No. 1 spot in the Z-order,
regardless of other applications that might want to bump me off the
top?

3) In order to "pick" the word off for example, the web browser, I
want to:
    a) intercept the activate message my Picker Window receives when
it is clicked
    b) examine the message to determine the last activated window
    c) send this last activated window a WM_COPY message to determine
which word the user has just highlighted.

The problem here is that WndProc can't be overridden in the CF. I've
read up on the MessageWindow but figured out I can't use this to
capture my Word Picker Messages. The alternative is a several hundred
lines of code from the MS CF team blog, but I don't have the time and
energy to implement this. It also seems like an awfully long work
around for a very simple problem.

Can someone suggest a simpler way of doing this?

Thanks in advance.
Click to expand...

Don't know enough to help with the first two questions, but I can
address #3. I assume you're referring to the "Subclassing controls in
CF 2.0" post at http://blogs.msdn.com/netcfteam/archive/2005/05/20/420551.aspx
.. Yes, the code in that post is somewhat longwinded, but it does
provide a complete solution to hooking a WndProc in the CF. The key
is the line "oldWndProc = Win32.SetWindowLong(hwnd, Win32.GWL_WNDPROC,
Marshal.GetFunctionPointerForDelegate(newWndProc));" Marshal.GFPFD()
gives you an IntPtr that serves as a handle to a .NET function, which
can then be passed to native code.

Unfortunately, anything dealing with Win32 programming (and WndProcs
in particular) is going to be somewhat long and tedious. However, the
code provided by the CF team shouldn't need any modifications. All
you should have to do is paste the code into your project, create a
function that matches the WndProcCallback delegate, and call
HookWndProc().

Hope that helps!

Mark Erikson
http://www.isquaredsoftware.com
 
Thanks for your suggestion Mark, I'll give it a go.

I would still appreciate feedback on my first two problems too, if
anyone out there knows the solution.

Thanks
 
To hide the start bar, make sure your form is maximized and the form's
clientsize is set to the full size of the screen.

Setting your form to TopMost = true; will bring it to the top, but you
have to get creative to keep it there.

To hide the start bar and SIP, here's the C++ code to do it, but you
will need to p/invoke these commands to make them work in C#. www.pinvoke.net
can help you our with that.

AFX_MANAGE_STATE(AfxGetStaticModuleState());
HWND hWnd = ::FindWindow( _T( "HHTaskBar" ), NULL );
::ShowWindow( hWnd, SW_HIDE ); // hide taskbar - use SW_RESTORE to
put it back
::EnableWindow(hWnd,false); // disable taskbar
 
Thanks Lcubed, but I'm not looking to hide the Start bar completely.
What I want to do is have a small floating window, roughly 10x10
pixels in size, which I can move anywhere on the entire screen area,
including over the Start bar, and never have it covered.

I'm thinking now of implementing a timer, to reset its topmost
behaviour every certain interval, but I know this will chew CPU and
also cause the window to flash. But at the moment I can't think of
another way of doing this.
 
I've thought of another way of being able to always be on top of the
startbar.

That is, to make my picker window a child of the start bar. In that
way, because the child will never be shown behind the parent, my
problem will be solved.

However, how do I get the startbar as a parent/owner form in my
application?

I can get the window handle of the startbar by following Lcubed's code
above. But how can I covert this handle to a form and set it to be the
owner of my picker form?

For a desktop application I believe Control.FromHandle would be the
solution, but unfortunately this is not implemented in the .NetCF.

Any workarounds or other suggestions?
 
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