Is there any specific reason why you'd want that?
I guess you could make an array like this:
FileStream[] fileStreams = new FileStream[dirs.Length];
for (int i = 0; i < dirs.Length; i++)
{
fileStreams[i] = new FileStream(dirs[i], FileMode.Open, FileAccess.Write);
}
Again I do not encourage this at all! If you do this just make sure to do another for loop once you're done to close all the FileStreams and dispose them!