Navigating an Item Tree

An application navigates a Windows Image Acquisition (WIA) device's item tree to find and select images on that device. Using this technique, an application selects and acquires an image without presenting a dialog box to the user.

A WIA device is represented as the root item in a tree of IWiaItem or IWiaItem2 objects. The child items in the tree represent images for a camera or scan beds for a scanner.

After a WIA device is selected, an application calls the IWiaItem::EnumChildItems method of the IWiaItem or IWiaItem2 interface of the device to enumerate the child items (the images or scan beds) of the device. For instructions, see Selecting a Device.

The IWiaItem::EnumChildItems method creates an enumeration object for the child items of the device, and returns a pointer to that object's IEnumWiaItem interface. The application can then use the methods of the IEnumWiaItem interface to obtain pointers to the items in the device's item tree.

 

 

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