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Article: Q104959
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kb16bitonly kbMessageBox kbSDKPlatform
Last Modified: 09-JUN-1999

3.10
WINDOWS
kbprg

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
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SUMMARY
=======

There are two kinds of system modal message boxes:

- Hard System Modal Message Box A hard system modal message box is the only
  window in the system that will receive messages.

- Soft System Modal Message Box All windows owned by a soft system modal
  message box's task will receive messages. No other window in the system will
  receive messages.

MORE INFORMATION
================

If a task wants to bring up a system modal message box and requires that
messages be received by its other windows, a soft system modal message box must
be used. For example, a task may require that WM_TIMER messages be received by a
window it owns even while it displays a system modal message box. On the other
hand, a hard system modal message box will prevent any other window in the
system from receiving messages. A hard system modal message box is also
appropriate in low memory situations because it uses very few system resources.

Both hard and soft system modal message boxes are created using MessageBox(). The
MB_ICON* flags indicate the kind of system modal message box to be created.

A hard system modal message box can be created using MessageBox() and by
including the following flags in the fuStyle parameter:

    MB_SYSTEMMODAL

or   MB_SYSTEMMODAL | MB_ICONHAND
or   MB_SYSTEMMODAL | MB_ICONSTOP

(Other flags such as MB_OK, MB_OKCANCEL, and so forth can also be used. However
do not use any other MB_ICON* flags).

A soft system modal message box can be created by including the following flags
in the fuStyle parameter

  MB_SYSTEMODAL | MB_ICON*

where MB_ICON* is any MB_ICON* style except MB_ICONHAND or MB_ICONSTOP.

(Other flags such as MB_OK, MB_OKCANCEL, and so forth can also be used. However
do not use MB_ICONHAND or MB_ICONSTOP.)

Note that other tasks in the system do not receive any messages when a task puts
up a hard or soft system modal message box.

Additional query words:

======================================================================
Keywords          : kb16bitonly kbMessageBox kbSDKPlatform 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : WINDOWS:3.1
Issue type        : kbinfo

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Q104959: INFO: Types of System Modal Message Boxes