IWiaMiniDrv COM interface

Imaging applications make requests to the WIA service, which in turn communicates with the device minidriver through the minidriver writer-implemented IWiaMiniDrv interface. Applications typically make requests for:

• Creating and initializing items

• Deleting items

• Enumerating device capabilities

• Enumerating image formats

• Issuing device commands

• Locking and unlocking a device

• Notifying a device of an event

• Obtaining device error strings

• Reading and storing item properties

• Transferring data

Applications make requests to the WIA service through the WIA application programming interface (API). For more information about this interface, see the Microsoft Windows SDK documentation.

The IWiaMiniDrv interface provides the entry points shown in the following tables for the WIA service to control the device. A WIA minidriver must implement every IWiaMiniDrv method. These entry points are defined through the following IWiaMiniDrv methods.

Creating and initializing items

Method	Description
IWiaMiniDrv::drvAnalyzeItem	Inspects an item and, if necessary, creates subitems.
IWiaMiniDrv::drvInitializeWia	Initializes the WIA minidriver.
IWiaMiniDrv::drvInitItemProperties	Initializes driver item properties for each item in an application item tree.

Deleting items

Method	Description
IWiaMiniDrv::drvDeleteItem	Deletes a driver item.
IWiaMiniDrv::drvFreeDrvItemContext	Frees a device-specific context.
IWiaMiniDrv::drvUnInitializeWia	Releases device resources associated with an application item tree.

Enumerating device capabilities

Method	Description
IWiaMiniDrv::drvGetCapabilities	Reports the events and commands supported by a WIA minidriver.

Enumerating image formats

Method	Description
IWiaMiniDrv::drvGetWiaFormatInfo	Gets supported device formats and media types.

Issuing device commands

Method	Description
IWiaMiniDrv::drvDeviceCommand	Issues a command to an imaging device.

Locking and unlocking a device

Method	Description
IWiaMiniDrv::drvLockWiaDevice	Locks access to an imaging device.
IWiaMiniDrv::drvUnLockWiaDevice	Unlocks access to an imaging device.

Notifying a device of an event

Method	Description
IWiaMiniDrv::drvNotifyPnPEvent	Indicates a WIA minidriver's response to a Plug and Play event.

Obtaining device error strings

Method	Description
IWiaMiniDrv::drvGetDeviceErrorStr	Maps a device error value to a string.

Reading and storing item properties

Method	Description
IWiaMiniDrv::drvReadItemProperties	Reads driver item properties.
IWiaMiniDrv::drvValidateItemProperties	Validates driver item properties.
IWiaMiniDrv::drvWriteItemProperties	Writes driver item properties to the device (if needed).

Transferring data

Method	Description
IWiaMiniDrv::drvAcquireItemData	Transfers data from a driver item to the WIA service.