How to use IWDFileUpload to load xml in byte array

In IDE V7.0, how do we get the byte array of the xml file from the local file upload. In old Web Dynpro version, one defines binary and filename in the context node and binds them to data and file name in the control property, then the xml can be uploaded from local xml. However, in 7.0, a new property as "resource" is introduced to replace data and filename properties. I could not find sample code about how to read the local xml file into byte array. Please help. Thanks.