Imaging Features > TWAIN and WIA > Windows Image Acquisition (WIA) > Managing WIA Sources

Managing WIA Sources

After a handle to a WIA session has been established, you need to select the WIA source to use for acquiring images. This is because WIA does not feature default device selection. Use the WiaSession.EnumDevices function to determine the WIA sources available on the system. This function enumerates all available WIA sources and calls the EnumDevicesEvent event for each WIA source found, retrieving its ID, name and description.

LEADTOOLS WIA offers two functions for selecting the WIA source to use for acquiring images:

WiaSession.SelectDeviceDlg: Displays a dialog that lists all available sources installed on the system in order for the user to select a device.
WiaSession.SelectDevice: Selects the WIA device without displaying the Select Device dialog. To use this method, enumerate the WIA devices by calling the EnumDevices method. Then keep a list of all received device IDs. Then call the SelectDevice function using the device ID for the device to be selected.

Once a device is selected, use the GetSelectedDevice method to get the selected device ID as a string. Use the SelectedDeviceType property to determine the type of the device currently selected at runtime to determine whether it is a scanner, camera or streaming video device.