IDirectInput8::EnumDevices Method

Enumerates available devices.

Syntax

HRESULT EnumDevices(      

    DWORD dwDevType,
    LPDIENUMDEVICESCALLBACK lpCallback,
    LPVOID pvRef,
    DWORD dwFlags
);

Parameters

dwDevType
Device type filter.
To restrict the enumeration to a particular type of device, set this parameter to a DI8DEVTYPE_* value. See DIDEVICEINSTANCE.
To enumerate a class of devices, use one of the following values.
DI8DEVCLASS_ALL
All devices.
DI8DEVCLASS_DEVICE
All devices that do not fall into another class.
DI8DEVCLASS_GAMECTRL
All game controllers.
DI8DEVCLASS_KEYBOARD
All keyboards. Equivalent to DI8DEVTYPE_KEYBOARD.
DI8DEVCLASS_POINTER
All devices of type DI8DEVTYPE_MOUSE and DI8DEVTYPE_SCREENPOINTER.
lpCallback
Address of a callback function to be called once for each device enumerated. See DIEnumDevicesCallback.
pvRef
Application-defined 32-bit value to be passed to the enumeration callback each time it is called.
dwFlags
Flag value that specifies the scope of the enumeration. This parameter can be one or more of the following values:
DIEDFL_ALLDEVICES
All installed devices are enumerated. This is the default behavior.
DIEDFL_ATTACHEDONLY
Only attached and installed devices.
DIEDFL_FORCEFEEDBACK
Only devices that support force feedback.
DIEDFL_INCLUDEALIASES
Include devices that are aliases for other devices.
DIEDFL_INCLUDEHIDDEN
Include hidden devices. For more information about hidden devices, see DIDEVCAPS.
DIEDFL_INCLUDEPHANTOMS
Include phantom (placeholder) devices.

Return Value

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.
DIERR_INVALIDPARAM An invalid parameter was passed to the returning function, or the object was not in a state that permitted the function to be called. This value is equal to the E_INVALIDARG standard Component Object Model (COM) return value.
DIERR_NOTINITIALIZED The object has not been initialized.

Remarks

All installed devices can be enumerated, even if they are not present. For example, a flight stick might be installed on the system but not currently plugged into the computer. Set the dwFlags parameter to indicate whether only attached or all installed devices should be enumerated. If the DIEDFL_ATTACHEDONLY flag is not present, all installed devices are enumerated.
A preferred device type can be passed as a dwDevType filter so that only the devices of that type are enumerated.
On Microsoft?Windows?XP, Microsoft DirectInput?enumerates only one mouse and one keyboard device, referred to as the system mouse and the system keyboard. These devices represent the combined output of all mice and keyboards respectively on a system. For information about how to read from multiple mice or keyboards individually on Windows XP, see the WM_INPUT documentation.
Note The order in which devices are enumerated by DirectInput is not guaranteed.

DIERR_INVALIDPARAM	An invalid parameter was passed to the returning function, or the object was not in a state that permitted the function to be called. This value is equal to the E_INVALIDARG standard Component Object Model (COM) return value.
DIERR_NOTINITIALIZED	The object has not been initialized.