width of combo box

[crazy boy]

I have small space on Sheet page and lots of controls. I have combo boxes, which take place, and I need to make them slim, so if I click on it the items should expand. I need to auto-change the width of the items which expand to fit the width of the longest item. Is there some style for this or way how to do it?

These styles I have applied:
CBS_DROPDOWNLIST | WS_VSCROLL | WS_TABSTOP

[2kaud]

You want to change the size of the combo-box list box so that it fits the width of the longest item?

This is possible. First you need to determine the required width of the list box. Then you process CBN_DROPDOWN notification (https://msdn.microsoft.com/en-us/lib...=vs.85%29.aspx) which happens when the list box of a combo control is about to become visible. Then use CB_GETCOMBOBOXINFO message (https://msdn.microsoft.com/en-us/lib...=vs.85%29.aspx) to obtain the HWND of the list box, then use GetWindowRect() and MoveWIndow() to resize the list box.

This is an extract from some code (so won't compile but will give the general idea)

COMBOBOXINFO cbinfo;
RECT rdraw;

//Get handles to combo windows
cbinfo.cbSize = sizeof(COMBOBOXINFO);
SendMessage(hwndItem, CB_GETCOMBOBOXINFO, 0, (LPARAM) (COMBOBOXINFO*) &cbinfo);

//Get position of current list box so new one starts at same position
GetWindowRect(cbinfo.hwndList, &rdraw);

//Make list window new required size
MoveWindow(cbinfo.hwndList, rdraw.left, rdraw.top, comwidth, rdraw.bottom - rdraw.top, TRUE);

//Set font for new list window
SendMessage(cbinfo.hwndList, WM_SETFONT, (WPARAM)GetStockObject(ANSI_FIXED_FONT), TRUE);

[VictorN]

There is a CB_SETDROPPEDWIDTH message that can be used.
Before sending it, it is necessary to obtain the max width of all the combo items. you could use GetTextExtentPoint32 or similat function...

[2kaud]

There is a CB_SETDROPPEDWIDTH message that can be used.

Note that this requires Vista or higher.

[VictorN]

There is a CB_SETDROPPEDWIDTH message that can be used.

Note that this requires Vista or higher.

Interesting!
I didn't know such a requirement and used MFC CComboBox::SetDroppedWidth() which internally sends CB_SETDROPPEDWIDTH message) under Window98/NT more than a decade back...

[VictorN]

From my MSDN of October 2000:

CB_SETDROPPEDWIDTH
An application sends the CB_SETDROPPEDWIDTH message to set the maximum allowable width, in pixels, of the list box of a combo box with the CBS_DROPDOWN or CBS_DROPDOWNLIST style.
...
Requirements
Windows NT/2000: Requires Windows NT 4.0 or later.
Windows 95/98: Requires Windows 95 or later.
Header: Declared in Winuser.h; include Windows.h.

[2kaud]

Well that's just Microsoft! The current documentation states the minimum requirement is Vista. https://msdn.microsoft.com/en-us/lib...=vs.85%29.aspx Doh!!

[VictorN]

I guess there was the "work" of some young MSFT employee that never heard about any system preceding Vista.
Sure he/she does not know about punch cards either!

PS: I have now "updated" this site:
https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

[2kaud]

I guess there was the "work" of some young MSFT employee that never heard about any system preceding Vista.
Sure he/she does not know about punch cards either!

PS: I have now "updated this site:
https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

The employee has been busy! eg CreateFile() is stated as minimum Windows XP and CreateWindow() as Windows 2000! Doh!!