openFileDialog读取文件转换字符串有关问题

openFileDialog读取文件转换字符串问题
我在msdn上拷贝了一段代码用来学习openFileDialog的使用
如下：
Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
  Dim myStream As Stream = Nothing
  Dim openFileDialog1 As New OpenFileDialog()

  openFileDialog1.InitialDirectory = "c:\"
  openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
  openFileDialog1.FilterIndex = 2
  openFileDialog1.RestoreDirectory = True

  If openFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
  Try
  myStream = openFileDialog1.OpenFile()
  If (myStream IsNot Nothing) Then
  ' Insert code to read the stream here.
  End If
  Catch Ex As Exception
  MessageBox.Show("Cannot read file from disk. Original error: " & Ex.Message)
  Finally
  ' Check this again, since we need to make sure we didn't throw an exception on open.
  If (myStream IsNot Nothing) Then
  myStream.Close()
  End If
  End Try
  End If
End Sub
我想做的事情是，打开openFileDialog1选择一个TXT文件，读取这个 TXT文件到一个richbox中。
但是现在发现自己对Stream 这个特性不了解，无法将myStream 写入richbox中
求高手指导一下

另外，能不能从哪里读到openFileDialog1打开文件的文件路径呢

[解决办法]

VB.NET code

 Dim ofd As New System.Windows.Forms.OpenFileDialog()        ofd.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"        Dim r As System.Windows.Forms.DialogResult = ofd.ShowDialog()        If r = Windows.Forms.DialogResult.OK Then           Dim sr As System.IO.StreamReader = New IO.StreamReader(ofd.FileName, System.Text.Encoding.GetEncoding("GB2312"))            richtextbox1.Text = sr.ReadToEnd‘一次性读取              'richtextbox1.Text & = sr.ReadLine ‘逐行读取            sr.Close()        End If