SAMPLE: UpDnDate.exe Implements a DateTime Control with a Spin Button and Callback Fields

ID: Q224570

The information in this article applies to:

Microsoft Visual C++, 32-bit Editions, version 6.0

SUMMARY

UpDnDate.exe is a sample that demonstrates how the new DateTime picker control can be used in an MFC application. In addition to illustrating the code that needs to be written in order to use such a control with callback fields, the sample also shows how to handle notifications sent by the child spin button created when the DTS_UPDOWN style is specified for the date time control.

MORE INFORMATION

The following file is available for download from the Microsoft Software Library:

UpDnDate.exe

Release Date:

For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base:

Q119591 How to Obtain Microsoft Support Files from Online Services

The code included is based on a Visual C++ version 6.0 AppWizard generated dialog based application. The points of interest are:

The datetime picker control inserted in the dialog template has the DTS_UPDOWN style.

The WM_INITDIALOG handler for the parent dialog defines the callback field, with a call to CDateTimeCtrl::SetFormat().

The CDateTimeCtrl-derived class CUDDateTimeCtrl implements handlers for the relevant reflected notifications: DTN_FORMAT, DTN_FORMATQUERY, DTN_WMKEYDOWN, following the guidelines from the online help.

CUDDateTimeCtrl implements a handler for the UDN_DELTAPOS notification, sent to the date time control by the child spin button (created due to the DTS_UPDOWN style).

CUDDateTimeCtrl::OnNotifyDeltaPos() cannot identify the field that has the focus. To work around this, the control sends a WM_KEYDOWN and WM_KEYUP message (with VK_UP or VK_DOWN as arguments) to itself.

CUDDateTimeCtrl::OnNotifyDeltaPos() shortcuts the default implementation, even for the standard fields of the control. Instead, it posts WM_KEYDOWN, WM_KEYUP messages to the control. This is done in order to work around a bug that exists in the date time picker common control shipped with Internet Explorer 4.0 (comctl32.dll version 4.70-4.72). The bug is fixed in the Internet Explorer 5.0 release (comctl32.dll version 5.00).

To see the control in action, build the project and run it. Set the focus to the custom field and either press the up or down arrow keys or use the mouse to click on the up or down buttons of the spin control. You'll see that all fields of the date time control are updated as expected.

Additional query words: kbfile, kbsample, kbmfc, DateTimePicker


Keywords          : kbfile kbsample kbCtrl kbDateTime kbMFC kbUpDownCtrl kbVC kbVC600 kbDSupport 
Version           : winnt:6.0
Platform          : winnt 
Issue type        :

Last Reviewed: June 14, 1999