Value Description
FileMode.Appendappend to the end of file.
FileMode.Createcreate a new output file. Any preexisting file by the same name will be destroyed.
FileMode.CreateNewcreate a new output file. The file must not already exist.
FileMode.Openopen a preexisting file.
FileMode.OpenOrCreateopen a file if it exists, or create the file if it does not already exist.
FileMode.Truncateopen a preexisting file, but reduce its length to zero.
If you want to restrict access to just reading or just writing, use this constructor:
FileStream(string filename, FileMode mode, FileAccess how)
'how' determines how the file can be accessed.
'how' must be one of:
FileAccess.Read
FileAccess.Write
FileAccess.ReadWrite