override protected FileSystemFileStream ImplOpenFile(String FileName, FileMode FileMode)
{
//var Stream = File.Open(RealPath(FileName), FileMode, FileAccess.Read, FileShare.ReadWrite);
var Stream = File.Open(RealPath(FileName), FileMode, FileAccess.ReadWrite, FileShare.ReadWrite);
return new FileSystemFileStreamStream(this, Stream);
}