CB_SETITEMHEIGHT message

An application sends a CB_SETITEMHEIGHT message to set the height of list items or the selection field in a combo box.

wParam

Specifies the component of the combo box for which to set the height.

This parameter must be 1 to set the height of the selection field. It must be zero to set the height of list items, unless the combo box has the CBS_OWNERDRAWVARIABLE style. In that case, the wParam parameter is the zero-based index of a specific list item.

lParam

Specifies the height, in pixels, of the combo box component identified by wParam.

If the index or height is invalid, the return value is CB_ERR.

The selection field height in a combo box is set independently of the height of the list items. An application must ensure that the height of the selection field is not smaller than the height of a particular list item.

Reference

CB_GETITEMHEIGHT

WM_MEASUREITEM