COMPAREITEMSTRUCT

3.0

typedef struct tagCOMPAREITEMSTRUCT {   /* cis */
    UINT  CtlType;
    UINT  CtlID;
    HWND  hwndItem;
    UINT  itemID1;
    DWORD itemData1;
    UINT  itemID2;
    DWORD itemData2;
} COMPAREITEMSTRUCT;

The COMPAREITEMSTRUCT structure supplies the identifiers and application-supplied data for two items in a sorted owner-drawn combo box or list box.

Whenever an application adds a new item to an owner-drawn combo or list box created with the CBS_SORT or LBS_SORT style, Windows sends the owner a WM_COMPAREITEM message. The lParam parameter of the message contains a long pointer to a COMPAREITEMSTRUCT structure. When the owner receives the message, it compares the two items and returns a value indicating which item sorts before the other. For more information, see the description of the WM_COMPAREITEM message in Chapter 2, “Messages.”

Members

CtlType

Specifies ODT_LISTBOX (which identifies an owner-drawn list box) or ODT_COMBOBOX (which identifies an owner-drawn combo box).

CtlID

Specifies the identifier of the list box or combo box.

hwndItem

Identifies the control.

itemID1

Specifies the index of the first item in the list box or combo box being compared.

itemData1

Specifies application-supplied data for the first item being compared. (This value was passed as the lParam parameter of the message that added the item to the combo box or list box.)

itemID2

Specifies the index of the second item in the list box or combo box being compared.

itemData2

Specifies application-supplied data for the second item being compared. This value was passed as the lParam parameter of the message that added the item to the combo box or list box.