StreamReade.peek读取到一般退的问题

大家帮忙看看：
Dim objClient As New System.Net.Sockets.TcpClient
objClient.Connect("10.10.0.216", 8888)

Dim objStream As System.Net.Sockets.NetworkStream
objStream = objClient.GetStream()

Dim objWriter As System.IO.StreamWriter = New System.IO.StreamWriter(objStream, System.Text.Encoding.Default)
objWriter.Write(TextBox1.Text)
objWriter.Flush()

Dim objReader As System.IO.StreamReader
objReader = New System.IO.StreamReader(objStream, System.Text.Encoding.Default)

Dim strRev As String

Dim i As Integer = 1

While objReader.Peek() > -1
ListBox2.Items.Add(objReader.Peek() & "/" & i)
strRev = objReader.ReadLine().ToString
ListBox2.Items.Add(strRev)
If Trim(strRev) = "</TX_INFO>" Then Exit While
i += 1
End While
ListBox2.Items.Add(objReader.Read())
ListBox2.Items.Add("</TX>")
Me.Refresh()
Me.ListBox2.SetSelected(ListBox2.Items.Count - 1, True)

objReader.Close()
objStream.Close()
objClient.Close()

其中的 While objReader.Peek() > -1
ListBox2.Items.Add(objReader.Peek() & "/" & i)
strRev = objReader.ReadLine().ToString
ListBox2.Items.Add(strRev)
If Trim(strRev) = "</TX_INFO>" Then Exit While
i += 1
End While
在数据流读取到一半时会退出（objReader.Peek() ＝-1），而用While objReader.Read() > -1则可以全部读出来，但Read会移动位置，读出来的每行数据流前面会少了2个字节。这是为什么啊？在线等，谢谢了！