Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        TextBox5.Text = GetStringBuilderCode("d:\text.txt")
    End Sub
 
    Private Function GetStringBuilderCode(ByVal path As String) As String
        Dim lines() As String = IO.File.ReadAllLines(path)
        Dim code As New System.Text.StringBuilder
        For Each l As String In lines
            code.Append("sb.AppendLine(""")
            code.Append(l)
            code.AppendLine(""")")
        Next
        Return code.ToString
    End Function