No an affidavit is hearsay, i.e. an out of court statement used to assert the truth of what is said therein.
It - the affidavit - can't be cross-examined.
The State has an absolute right to confront and cross-examine your witnesses just as your attorney has the right to confront the witnesses testifying for the State. You should try to continue the case so that your witness can be there to testify, otherwise the statement isn't coming into evidence.
You should definitely try to continue your case but there is a rule of evidence under which it may be possible to use the affidavit. Rule 804 of the North Carolina Evidence Code provides an exception to the hearsay rule when (1) the witness is "unavailable" as defined by the rule and (2) the affiant's testimony satisfies the "trustworthiness" requirements set forth in the rule. The rule also requires that the other party be given written notice of the intention to use the affidavit sufficiently in advance so as to give them a fair opportunity to prepare to respond to the affidavit. The application of this rule is complicated and you should definitely consult with a lawyer about how it may apply to the particular facts of your case.