Why cannot System.IO.StreamReader read from my custom stream?

Question

I'm in the process of creating a custom stream for an API endpoint in my app. The stream needs to have custom logic that I don't want to get into, but suffice to say I can't use a built-in stream class.

I did the minimum necessary to implement a read-only stream (inheriting from System.IO.Stream) and I've verified that the System.IO.BinaryReader class can read from my stream:

Dim reader As New System.IO.BinaryReader(GenerateStream(business, logic))
Dim enc As New System.Text.ASCIIEncoding
Dim contents As String = enc.GetString(reader.ReadBytes(CType(reader.BaseStream.Length, Int32)))

The string "contents" contains the correct string for the entire stream.

However, I would like to be able allow the use of the System.IO.StreamReader class:

Dim reader As New System.IO.StreamReader(GenerateStream(business, logic), System.Text.Encoding.ASCII)
Dim contents As String = reader.ReadToEnd

but for whatever reason the ReadToEnd always returns the empty string.

Any ideas?

Here's the stream:

Public Overrides ReadOnly Property CanRead() As Boolean
   Get
    Return True
   End Get
  End Property

  Public Overrides ReadOnly Property CanSeek() As Boolean
   Get
    Return False
   End Get
  End Property

  Public Overrides ReadOnly Property CanWrite() As Boolean
   Get
    Return False
   End Get
  End Property

  Public Overrides Sub Flush()
   'this method intentionally left blank'
  End Sub

  Public Overrides ReadOnly Property Length() As Long
   Get
    Return 'some business logic'
   End Get
  End Property

  Public Overrides Property Position() As Long
   Get
    Return bytePosition
   End Get
   Set(ByVal value As Long)
    Throw New System.NotSupportedException
   End Set
  End Property

  Public Overrides Function Read(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer) As Integer
   'I return 0 on an end of stream, otherwise the # of bytes successfully read.'
  End Function

  Public Overrides Function Seek(ByVal offset As Long, ByVal origin As System.IO.SeekOrigin) As Long
   Throw New System.NotSupportedException
  End Function

  Public Overrides Sub SetLength(ByVal value As Long)
   Throw New System.NotSupportedException()
  End Sub

  Public Overrides Sub Write(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer)
   Throw New System.NotSupportedException()
  End Sub

Answer 1

Try doing this:

Dim reader As New System.IO.StreamReader(
    GenerateStream(business, logic), 
    System.Text.Encoding.ASCII, 
    False
)
Dim contents As String = reader.ReadToEnd

Also make sure all the methods you don't want used will throw NotImplementedException.