Instructions

U.are.U SDK - Developer Guide 55
ActiveX
Note that serialized FMDs and FIDs include the version number of the ActiveX API that was used for the serialization.
If you attempt to deserialize with an older version of the API, the results may not be correct, so when deserializing, the
API will throw an SDKException if the serialization was done using a later version of the wrapper.
Serialization in the API occurs using the default System.Xml.Serialization.XmlSerializer. The name
of the root element of the generated XML is the same as the object type. Each public member of the object is
represented as an XML element. Raw byte data is encoded as a Base-64 string by XmlSerializer.
Deserialization also uses XmlSerializer. The XML that was serialized is fed into XmlSerializer where the
elements with values become object members with values of the same name as the element.
Working with Readers
Readers are accessed through the XReaderCollection object, which is a collection of XReader objects.
Each attached reader is represented with a XReader object. The XReader interface allows:
• Querying reader description and capabilities,
• Acquiring status of the reader,
• Capturing fingerprints,
• Starting and stopping image stream, and
• Resetting and calibrating the reader.
To acquire a reader, first instantiate a XReaderCollection object and call
XReaderCollection.GetReaders() which returns the attached readers. Iterate through this list to look at the
description object for the desired reader. Once finished with all of the XReader objects in the
XReaderCollection, ensure that you call the Dispose() method to destroy the XReaderCollection
object and release system resources.
A Note About Internet Explorer and Process Merging
By default, Internet Explorer merges browser processes where it can, beginning with IE8. If your application is open in
more than one browser window, users may experience erroneous behavior when your application calls
XReader.Dispose() from one window.
To prevent this, users can use the File > New Session command to open a new window that does not merge processes
with existing windows. You can also prevent IE from merging processes by using the -nomerge command line option
when launching IE OR change the registry setting of HKEY_CURRENT _USER\Software\Microsoft\
Internet Explorer\Main to set SessionMerging to 0. Note however that these options will affect Internet
Explorer/s efficiency and startup time.