Public Class MarshallingStream 
   Inherits BaseStream

public class MarshallingStream : BaseStream 

byte[] dataIn = new byte[1024];
byte[] copy;
new Random().NextBytes(dataIn);
GCHandle h = GCHandle.Alloc(dataIn, GCHandleType.Pinned);
try
{
    using (MarshallingStream stream = new MarshallingStream(h.AddrOfPinnedObject(), false, dataIn.Length))
    {
        Assert.IsTrue(stream.CanRead);
        Assert.IsTrue(stream.CanWrite);
        Assert.IsTrue(stream.CanSeek);

        copy = new byte[(int)stream.Length];
        IOStream.Read(stream, copy, (int)stream.Length);
        Assert.AreEqual(dataIn, copy);
        Assert.AreEqual(stream.Length, stream.Position);
        stream.Position = 0;
        Assert.AreEqual(0L, stream.Position);

        stream.Write(new byte[dataIn.Length], 0, dataIn.Length);
        Assert.AreEqual(new byte[dataIn.Length], dataIn);

        stream.Seek(0, SeekOrigin.Begin);
        Assert.AreEqual(0, stream.Position);
        stream.Write(copy, 0, dataIn.Length);
        Assert.AreEqual(dataIn, copy);

        stream.Seek(-10, SeekOrigin.Current);
        Assert.AreEqual(stream.Length - 10, stream.Position);

        stream.Seek(-stream.Length, SeekOrigin.End);
        Assert.AreEqual(0, stream.Position);

        stream.WriteByte(123);
        stream.Position = 0;
        Assert.AreEqual(123, stream.ReadByte());
    }

    using (MarshallingStream stream = new MarshallingStream(h.AddrOfPinnedObject(), true, dataIn.Length))
    {
        Assert.IsFalse(stream.CanWrite);

        copy = new byte[(int)stream.Length];
        IOStream.Read(stream, copy, (int)stream.Length);
        Assert.AreEqual(dataIn, copy);

        try
        {
            stream.Write(new byte[10], 0, 10);
            Assert.Fail();
        }
        catch (InvalidOperationException) { }

        stream.Dispose();
        try
        {
            stream.Read(new byte[10], 0, 10);
            Assert.Fail();
        }
        catch (ObjectDisposedException) { }
    }
}
finally { h.Free(); }

Dim dataIn As Byte() = New Byte(1024) {}
Dim copy As Byte()
New Random().NextBytes(dataIn)
Dim h As GCHandle = GCHandle.Alloc(dataIn, GCHandleType.Pinned)
Try
    Using stream As New MarshallingStream(h.AddrOfPinnedObject(), False, dataIn.Length)
        Assert.IsTrue(stream.CanRead)
        Assert.IsTrue(stream.CanWrite)
        Assert.IsTrue(stream.CanSeek)

        copy = New Byte(DirectCast(stream.Length, Integer)) {}
        IOStream.Read(stream, copy, DirectCast(stream.Length, Integer))
        Assert.AreEqual(dataIn, copy)
        Assert.AreEqual(stream.Length, stream.Position)
        stream.Position = 0
        Assert.AreEqual(0L, stream.Position)

        stream.Write(New Byte(dataIn.Length) {}, 0, dataIn.Length)
        Assert.AreEqual(New Byte(dataIn.Length) {}, dataIn)

        stream.Seek(0, SeekOrigin.Begin)
        Assert.AreEqual(0, stream.Position)
        stream.Write(copy, 0, dataIn.Length)
        Assert.AreEqual(dataIn, copy)

        stream.Seek(-10, SeekOrigin.Current)
        Assert.AreEqual(stream.Length - 10, stream.Position)

        stream.Seek(-stream.Length, SeekOrigin.[End])
        Assert.AreEqual(0, stream.Position)

        stream.WriteByte(123)
        stream.Position = 0
        Assert.AreEqual(123, stream.ReadByte())
    End Using

    Using stream As New MarshallingStream(h.AddrOfPinnedObject(), True, dataIn.Length)
        Assert.IsFalse(stream.CanWrite)

        copy = New Byte(DirectCast(stream.Length, Integer)) {}
        IOStream.Read(stream, copy, DirectCast(stream.Length, Integer))
        Assert.AreEqual(dataIn, copy)

        Try
            stream.Write(New Byte(10) {}, 0, 10)
            Assert.Fail()
        Catch generatedExceptionName As InvalidOperationException
        End Try

        stream.Dispose()
        Try
            stream.Read(New Byte(10) {}, 0, 10)
            Assert.Fail()
        Catch generatedExceptionName As ObjectDisposedException
        End Try
    End Using
Finally
    h.Free()
End Try