How can I lock a file while writing to it via a FileStream?

I am trying to figure out how to write a binary file with a FileStream and BinaryWriter, and keep the file locked for read while I am writing. I specifically don't want other applications/processes to be able to read from the while while its being written to.

//code to declare ba as a byte array

//dpath is the path to the file

FileStream BinaryFile = new FileStream(dpath, FileMode.Create, FileAccess.Write);

BinaryWriter Writer = new BinaryWriter(BinaryFile);

Writer.Write(ba);

Writer.Close();

BinaryFile.Dispose();

Now the problem is the file can be opened by other applications during the write, which is undesirable in my current application. The FileStream has a Lock Method, but that locks for writing and not for reading, so that doesn't help me.