FILE *fp=_tfopen("c:\test.txt","rws"); this code is equivalent to in C#
FileStream fp= new FileStream("c:\test.txt", FileMode.Create, FileAccess.Write,FileShare.Read);
FileStream fp= new FileStream("c:\test.txt", "rws");
FileStream fp= new FileStream("c:\test.txt", FileMode.ReadWriteShared);
FileStream fp= new FileStream("c:\test.txt", FileMode.ReadWrite, FileAccess.Shared);