StreamReader、StreamWriter

StreamReader

public class StreamReader : TextReader
{
　　 public StreamReader(Stream stream, Encoding encoding, bool detectEncodingFromByteOrderMarks, int bufferSize, bool leaveOpen)
    {
        if (stream == null || encoding == null)
            throw new ArgumentNullException((stream == null ? "stream" : "encoding"));
        if (!stream.CanRead)
            throw new ArgumentException(Environment.GetResourceString("Argument_StreamNotReadable"));
        if (bufferSize <= 0)
            throw new ArgumentOutOfRangeException("bufferSize", Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
        Contract.EndContractBlock();

        Init(stream, encoding, detectEncodingFromByteOrderMarks, bufferSize, leaveOpen);
    }

    internal void Init(Stream stream)
    {
        this.stream = stream;
        _closable = true;
    }

    public override void Close()
    {
        Dispose(true);
    }

    protected override void Dispose(bool disposing)
    {
        try
        {
            if (!LeaveOpen && disposing && (stream != null))
                stream.Close();
        }
        finally
        {
            if (!LeaveOpen && (stream != null))
            {
                stream = null;
                encoding = null;
                decoder = null;
                byteBuffer = null;
                charBuffer = null;
                charPos = 0;
                charLen = 0;
                base.Dispose(disposing);
            }
        }
    }
}

 

StreamWriter

public class StreamWriter : TextWriter
{
    public override void Close()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected override void Dispose(bool disposing)
    {
        try
        {
            if (stream != null)
            {
                if (disposing || (LeaveOpen && stream is __ConsoleStream))
                {
#if FEATURE_ASYNC_IO
                    CheckAsyncTaskInProgress();
#endif

                    Flush(true, true);
#if MDA_SUPPORTED
                    // Disable buffered data loss mda
                    if (mdaHelper != null)
                        GC.SuppressFinalize(mdaHelper);
#endif
                }
            }
        }
        finally
        {
            if (!LeaveOpen && stream != null)
            {
                try
                {
                    if (disposing)
                        stream.Close();
                }
                finally
                {
                    stream = null;
                    byteBuffer = null;
                    charBuffer = null;
                    encoding = null;
                    encoder = null;
                    charLen = 0;
                    base.Dispose(disposing);
                }
            }
        }
    }

    public override void Flush()
    {
#if FEATURE_ASYNC_IO
        CheckAsyncTaskInProgress();
#endif

        Flush(true, true);
    }
}