IDirectInputDevice8::EnumObjects

Enumerates the input and output objects available on a device.

HRESULT EnumObjects(
  LPDIENUMDEVICEOBJECTSCALLBACK lpCallback,
  LPVOID pvRef,
  DWORD dwFlags
);

Parameters

lpCallback

Address of a callback function that receives DirectInputDevice objects. Microsoft® DirectInput® provides a prototype of this function as DIEnumDeviceObjectsCallback.

pvRef

Reference data (context) for callback.

dwFlags

Flags that specify the types of object to be enumerated. Each of the following values restricts the enumeration to objects of the described type:

DIDFT_ABSAXIS

An absolute axis.

DIDFT_ALIAS

Controls identified by a Human Interface Device usage alias. This flag applies only to HID-compliant USB devices.

DIDFT_ALL

All objects.

DIDFT_AXIS

An axis, either absolute or relative.

DIDFT_BUTTON

A push button or a toggle button.

DIDFT_COLLECTION

A Human Interface Device (HID) link collection. HID link collections do not generate data of their own.

DIDFT_ENUMCOLLECTION(n)

An object that belongs to HID link collection number n.

DIDFT_FFACTUATOR

An object that contains a force-feedback actuator. In other words, forces can be applied to this object.

DIDFT_FFEFFECTTRIGGER

An object that can be used to trigger force-feedback effects.

DIDFT_NOCOLLECTION

An object that does not belong to any HID link collection; in other words, an object for which the wCollectionNumber member of the DIDEVICEOBJECTINSTANCE structure is 0.

DIDFT_NODATA

An object that does not generate data.

DIDFT_OUTPUT

An object to which data can be sent by using the IDirectInputDevice8::SendDeviceData method.

DIDFT_POV

A point-of-view controller.

DIDFT_PSHBUTTON

A push button. A push button is reported as down when the user presses it and as up when the user releases it.

DIDFT_RELAXIS

A relative axis.

DIDFT_TGLBUTTON

A toggle button. A toggle button is reported as down when the user presses it and remains so until the user presses the button a second time.

DIDFT_VENDORDEFINED

An object of a type defined by the manufacturer.

Return Values

If the method succeeds, the return value is DI_OK.

If the method fails, the return value can be one of the following error values:

Remarks

The DIDFT_FFACTUATOR and DIDFT_FFEFFECTTRIGGER flags in the dwFlags parameter restrict enumeration to objects that meet all the criteria defined by the included flags. For all the other flags, an object is enumerated if it meets the criterion defined by any included flag in this category. For example, (DIDFT_FFACTUATOR | DIDFT_FFEFFECTTRIGGER) restricts enumeration to force-feedback trigger objects, and (DIDFT_FFEFFECTTRIGGER | DIDFT_TGLBUTTON | DIDFT_PSHBUTTON) restricts enumeration to buttons of any kind that can be used as effect triggers.

Applications should not rely on this method to determine whether certain keyboard keys or indicator lights are present, as these objects might be enumerated even though they are not present. Although the basic set of available objects can be determined from the device subtype, there is no reliable way of determining whether extra objects such as the menu key are available.

Requirements

  Windows NT/2000/XP: Requires Windows® 2000.
  Windows 98/Me: Requires Windows 98 or later. Available as a redistributable for Windows 98.
  Header: Declared in Dinput.h.