System.IO.FileStream.FileStream C# (CSharp) Method

        public FileStream(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, FileOptions options)
        {
            if (path == null)
                throw new ArgumentNullException(nameof(path), SR.ArgumentNull_Path);
            if (path.Length == 0)
                throw new ArgumentException(SR.Argument_EmptyPath, nameof(path));

            // don't include inheritable in our bounds check for share
            FileShare tempshare = share & ~FileShare.Inheritable;
            string badArg = null;

            if (mode < FileMode.CreateNew || mode > FileMode.Append)
                badArg = nameof(mode);
            else if (access < FileAccess.Read || access > FileAccess.ReadWrite)
                badArg = nameof(access);
            else if (tempshare < FileShare.None || tempshare > (FileShare.ReadWrite | FileShare.Delete))
                badArg = nameof(share);

            if (badArg != null)
                throw new ArgumentOutOfRangeException(badArg, SR.ArgumentOutOfRange_Enum);

            // NOTE: any change to FileOptions enum needs to be matched here in the error validation
            if (options != FileOptions.None && (options & ~(FileOptions.WriteThrough | FileOptions.Asynchronous | FileOptions.RandomAccess | FileOptions.DeleteOnClose | FileOptions.SequentialScan | FileOptions.Encrypted | (FileOptions)0x20000000 /* NoBuffering */)) != 0)
                throw new ArgumentOutOfRangeException(nameof(options), SR.ArgumentOutOfRange_Enum);

            if (bufferSize <= 0)
                throw new ArgumentOutOfRangeException(nameof(bufferSize), SR.ArgumentOutOfRange_NeedPosNum);

            // Write access validation
            if ((access & FileAccess.Write) == 0)
            {
                if (mode == FileMode.Truncate || mode == FileMode.CreateNew || mode == FileMode.Create || mode == FileMode.Append)
                {
                    // No write access, mode and access disagree but flag access since mode comes first
                    throw new ArgumentException(SR.Format(SR.Argument_InvalidFileModeAndAccessCombo, mode, access), nameof(access));
                }
            }

            if ((access & FileAccess.Read) != 0 && mode == FileMode.Append)
                throw new ArgumentException(SR.Argument_InvalidAppendMode, nameof(access));

            string fullPath = Path.GetFullPath(path);

            _path = fullPath;
            _access = access;
            _bufferLength = bufferSize;

            if ((options & FileOptions.Asynchronous) != 0)
                _useAsyncIO = true;

            _fileHandle = OpenHandle(mode, share, options);

            try
            {
                Init(mode, share);
            }
            catch
            {
                // If anything goes wrong while setting up the stream, make sure we deterministically dispose
                // of the opened handle.
                _fileHandle.Dispose();
                _fileHandle = null;
                throw;
            }
        }