IWiaItem::DeviceCommand method (wia_xp.h)

The IWiaItem::DeviceCommand issues a command to a Windows Image Acquisition (WIA) hardware device.

Syntax

HRESULT DeviceCommand(
  [in]      LONG       lFlags,
  [in]      const GUID *pCmdGUID,
  [in, out] IWiaItem   **pIWiaItem
);

Parameters

[in] lFlags

Type: LONG

Currently unused. Should be set to zero.

[in] pCmdGUID

Type: const GUID*

Specifies a unique identifier that specifies the command to send to the WIA hardware device. For a list of valid device commands, see WIA Device Commands.

[in, out] pIWiaItem

Type: IWiaItem**

On output, this pointer points to the item created by the command, if any.

Return value

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

Applications use this method to send WIA commands to hardware devices.

When the application sends the WIA_CMD_TAKE_PICTURE command to the device, IWiaItem::DeviceCommand, the WIA run-time system creates the IWiaItem object to represent the image. The IWiaItem::DeviceCommand method stores the address of the interface in the pIWiaItem parameter.

Applications must call the IUnknown::Release method on the interface pointers they receive through the pIWiaItem parameter.

Requirements