Me.DataGrid1.Controls.Add(New TextBox)
For each o as Object in Me.DataGrid1.Controls
   Debug.Write(o.ToString())
Next

private Sub CreateDataGridTextBoxColumn()
   Dim myTextBoxColumn As DataGridTextBoxColumn  = _
   New DataGridTextBoxColumn()
   ' Set the MappingName and Format properties.
   myTextBoxColumn.MappingName = "OrderDate"
   ' The character "D" means use the long date format.
   myTextBoxColumn.Format = "D"
   ' Add the column to the DataGridTableStyle object.
   dataGrid1.TableStyles("Orders").GridColumnStyles. _
   Add(myTextBoxColumn)
End Sub

 For Each o As Object In Me.DataGrid1.TableStyles
            If TypeOf (o) Is DataGridTextBox Then
                CType(o, DataGridTextBox).Height = 10
            ElseIf TypeOf (o) Is DataGridTextBoxColumn Then
                CType(o, DataGridTextBox).Height = 10
            End If
            ' usw
        Next