xamarin - There is no open() method for my DriveFile object -

i'm frustrated @ point due lack of documentation of google drive api , i'm using xamarin makes things worse. i've installed xamarin.googleplayservices.drive package , it's working properly. fast forward problem, query files , can driveid.

so code is:

drivefile file = driveid.asdrivefile(); //and here want use method file.open(...); 

the methods drivefile object has available default object methods e.g. tostring(), equals(), gettype() , gethashcode(). doing wrong, why can't access method since others have no problem accessing it.

google says must use it: https://developers.google.com/drive/android/files

this guy using xamarin has no problem using method: xamarin: unsure cast using drivefile.open

any appreciated. have access metadata of files if helps (to download using method)

i found solution problem. confusing name of classes. drivefile name of enum-like class of types of operations. idrivefile interface actual interface contains open method. when stored value var worked, can open method.

var file = onlinefiles[i].driveid.asdrivefile(); file.open(_googleapiclient, drivefile.modereadonly, null).setresultcallback(this);