VS 2010 Using a DataReader to populate a dataset

I'm having a bit of an issue with the following code. Basically, I have an oracle command that queries a database and returns records - that part works and is located above the snippet I've posted.

It loads the records into a datareader, and I can loop through the datareader - that works also.

Where I'm having a problem is - I want to loop through the datareader and load records into a datatable I've created (by dragging a Datatable object onto my form). I've then linked a datagridview on my form to that datatable.

The code below runs without error, but the datagridview doesn't populate with anything - wondering why?

The highlighted line below shows where I'm trying to see if there are any rows in my datatable. This always seems to be zero so the issue is somewhere in here I suspect.

Code:

---

Dim OracleCommand As New OracleCommand
        OracleCommand.Connection = con
        OracleCommand.CommandText = IP_SQL
        OracleCommand.CommandType = CommandType.Text

        Dim DataReader As OracleDataReader = OracleCommand.ExecuteReader()

        If DataReader.HasRows Then
            Do While DataReader.Read()
                Dim anyRow As DataRow = dtNRCWorking.NewRow
                anyRow("MRN") = Mid((DataReader.Item("CR_Number")), 3, 7)
                Dim intwow As Integer = dtNRCWorking.Rows.Count

            Loop

        End If

        DataGridView1.DataSource = dsNRCPicker
        DataGridView1.DataMember = "dtNRCWorking"
        DataGridView1.Refresh()
        DataReader.Close()

---

Now I'm sure some of you are wondering why I'm doing this in the first place. Well - in short, I need to query data, massage it, and create a tab delimited file with it.

The DataReader let's me query, the dataset lets me loop through and massage the records/fields that I need to massage, and the datagridview is just for testing purposes so I can have a quick look at the data I'm building.