# DM_SETDROPDOWNOPENED

The DM_SETDROPDOWNOPENED message is sent to the dialog manager to open or close a combo box or history list.

### Param1

The ID of the element for which the combo box (DI_COMBOBOX) or history list (DI_EDIT or DI_FIXEDIT with the DIF_HISTORY flag) should be opened.

### Param2

TRUE - open the list for the element with the given ID.
FALSE - close the open combo box or history list. In this case Param1 is ignored.

### Return

If Param2=FALSE the returned value is always TRUE.
If Param2=TRUE, the returned value is TRUE if the combo box or history list has been opened successfully. FALSE is returned if ID of not suppored type was set.

### Controls

Control | Description
--- | ---
DI_COMBOBOX | combined list
DI_EDIT | edit line
DI_FIXEDIT | fixed-size input field

### Remarks

Only one combo box or history list can be open in a dialog at the same time. Therefore, sending this message with Param2=`TRUE` closes an already opened combo box before opening the specified one, and when sending the message with Param2=`FALSE` it is not needed to specify the item ID.

### Example

See also:
DialogEx
DM_GETDROPDOWNOPENED