|
Overview |
|
|
|
Group |
|
|
|
Quick Info
Windows NT
| Yes
| Win95
| Yes
| Win32s
| Yes
| Import Library
| -
| Header File
| winuser.h
| Unicode
| No
| Platform Notes
| None
|
|
|
WM_MEASUREITEM
The WM_MEASUREITEM message is sent to the owner window of an owner-drawn
button, combo box, list box, list view control, or menu item when the control or
menu is created.
WM_MEASUREITEM
idCtl = (UINT) wParam; // control identifier
lpmis = (LPMEASUREITEMSTRUCT) lParam; // item-size information
Parameters
idCtl
Value of wParam. Contains the value of the CtlID member of the MEASUREITEMSTRUCT structure pointed to by the lpmis parameter. This value identifies the control that sent the WM_MEASUREITEM
message.
If the value is zero, the message was sent by a menu. If the value is nonzero,
the message was sent by a combo box or by a list box. If the value is nonzero,
and the value of the itemID member of the MEASUREITEMSTRUCT pointed to by lpmis is (UINT)  1, the message was sent by a combo edit field.
lpmis
Value of lParam. Points to a MEASUREITEMSTRUCT structure that contains the dimensions of the owner-drawn control or menu
item.
Return Values
If an application processes this message, it should return TRUE.
Remarks
When the owner window receives the WM_MEASUREITEM message, the owner fills in
the MEASUREITEMSTRUCT structure pointed to by the lParam parameter of the message and returns; this informs Windows of the dimensions
of the control. If a list box or combo box is created with the
LBS_OWNERDRAWVARIABLE or CBS_OWNERDRAWVARIABLE style, this message is sent to the owner for
each item in the control; otherwise, this message is sent once.
Windows sends the WM_MEASUREITEM message to the owner window of combo boxes
and list boxes created with the OWNERDRAWFIXED style before sending the
WM_INITDIALOG message. As a result, when the owner receives this message, Windows has
not yet determined the height and width of the font used in the control; function
calls and calculations requiring these values should occur in the main
function of the application or library.
See Also
MEASUREITEMSTRUCT, WM_INITDIALOG
Related Links
Software for Delphi and C++ Builder developers
Software for Visual Studio .NET developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET
TMS Scripter Studio Pro components for Delphi/C++Builder
More Online Helps
Win32 Multimedia Programmer's Reference (mmedia.hlp)
OLE Programmer's Reference (ole.hlp)
Microsoft Windows Pen API Programmer's Reference (penapi.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (tapi.hlp)
Unix Manual Pages
|
