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4/8/2010

This message is sent by a date and time picker (DTP) control to retrieve the maximum allowable size of the string that will be displayed in callback field. It is sent in the form of a WM_NOTIFY message.

Syntax 

DTN_FORMATQUERY 
lpDTFormatQuery = (LPNMDATETIMEFORMATQUERY) 
lParam;

Parameters

lpDTFormatQuery

Long pointer to an NMDATETIMEFORMATQUERYstructure that contains information about the callback field. The structure contains a substring that defines a callback field and receives the maximum allowable size of the of string that will be displayed in the callback field.

Remarks

The owner of the control must calculate the maximum possible width of the text that will be displayed in the callback field, set the szMaxmember of the NMDATETIMEFORMATQUERYstructure, and return zero.

Handling this message prepares the control to adjust for the maximum size of the string that will be displayed in a particular callback field. This enables the control to properly display output at all times, reducing flicker within the control's display. For additional information about callback fields, see Callback Fields.

Requirements

Header commctrl.h
Windows Embedded CE Windows CE 2.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also