关于ADODB.Stream输入流的问题

我在vs2010开发环境下，碰到如下问题，
主要是这句出错：
ado_stream.Write(ado_stream2.Read) 提示类型不匹配。源码如下：

        Dim srcfilename As String = "D:\test\l005_asmcg.smg"
        Dim srcurl As String = ""
        Dim user_up As String = "xx"
        Dim userpassword_up As String = "xxx"

        Dim boundary As String     ' 分隔符
        'Dim auth As String        ' 用户验证字符串格式：Base64(“用户名:密码”)
        Dim contentlength As Long  ' 传输文件总长度单位：字节
        Dim Filename As String     ' 文件名
        Dim crlf As String         ' 回车换行符

        boundary = "------------------1234567"
        crlf = Chr(13) & Chr(10)
        'MsgBox("test:" & crlf)
        'auth = "d2NhZG1pbjp3Y2FkbWlu"

        ' 设置HTTP消息

        Dim ado_stream As Object
        Dim ado_stream2 As Object
        Filename = Microsoft.VisualBasic.Right(srcfilename, Len(srcfilename) - InStrRev(srcfilename, "\"))
        MsgBox(Filename)

        ' 创建流并写入报头
        ado_stream = CreateObject("ADODB.Stream")
        ado_stream.Open()
        ado_stream.Type = 1
        ado_stream.Write(sTb("--" & boundary & crlf, ""))
        ado_stream.Write(sTb("Content-Disposition: form-data; name=""" & Filename & """;filename=""" & Filename & """" & crlf, ""))
        ado_stream.Write(sTb("Content-Type: application/octet-stream" & crlf, ""))
        ado_stream.Write(sTb(crlf, ""))
        MsgBox("xxx:" & ado_stream.Size)

        ' 新建流并写入文件内容
        ado_stream2 = CreateObject("ADODB.Stream")
        ado_stream2.Open()
        ado_stream2.Type = 1
        ado_stream2.LoadFromFile(srcfilename)
        contentlength = ado_stream2.Size   ' 传输文件总长度单位：字节
        MsgBox("大小：" & contentlength)

        ' 全并流内容并发送
        ado_stream.Write(ado_stream2.Read)
        MsgBox("分割3：xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

        ado_stream.Flush()
        ado_stream.Position = 0
        MsgBox("stream1的大小：" & ado_stream.Size)

        'XML.Send(ado_stream.Read)
        ado_stream2.Close()
        ado_stream.Close() --------------------编程问答-------------------- 补充，上面的代码在VB6.0下是没有问题的，但是在vb.net下报上述错误

补充：.NET技术 ,  VB.NET