I seem to have gotten the data grid so that I can edit individual columns but
it has brought up some questions.

1) The only way that I can get a column to be editable is to make the whole
datagrid not read-only. Like:

           Me.dgOrderItems.ReadOnly = False

The problem with that is that when I add a row to the datagrid I get two
rows, one that I added and one that just contains nulls (an empty row).  I
override the default DataGridTextBoxColumn and set the ReadOnly property to
False but unless the ReadOnly property is set for the whole grid I cannot
edit the columns. I only use the overriden DataGridTextBoxColumn for certain
columns:

           Dim dgEditableTextCol As New DataGridEditTextBoxColumn
           dgEditableTextCol.HeaderText = "QTY"
           dgEditableTextCol.MappingName = "qty"
           dgEditableTextCol.Width = 35
           dgEditableTextCol.ReadOnly = False
           dgTblStyle.GridColumnStyles.Add(dgEditableTextCol)

           dgEditableTextCol = New DataGridEditTextBoxColumn
           dgEditableTextCol.HeaderText = "Unit Price"
           dgEditableTextCol.MappingName = "UnitPrice"
           dgEditableTextCol.Width = 70
           dgEditableTextCol.Format = "C"
           dgEditableTextCol.ReadOnly = False
           dgTblStyle.GridColumnStyles.Add(dgEditableTextCol)

2) I have created a "calculated" column using the "Expression" property.

           Me.columnextendedprice = New
System.Data.DataColumn("extendedprice", GetType(Decimal), Nothing,
System.Data.MappingType.Element)
           Me.columnextendedprice.Expression = "qty * unitprice"
           MyBase.Columns.Add(Me.columnextendedprice)

The problem is that this caclulated column is not getting updated after a
column/row has been edited. It is only when I leave the row altogether that
this expression seems to be evaluated. Is there a way to force an earlier
update.

3) Finally, I need to update other fields on the form when the data in the
DataGrid has been edited. I need some sort of notification when the column
has been edited so I can update the other fields in the form. For the columns
that I want to edit I currently have:

      Protected Overloads Overrides Sub Edit(ByVal source As
CurrencyManager, ByVal rowNum As Integer, ByVal bounds As Rectangle, ByVal
[readOnly] As Boolean, ByVal instantText As String, ByVal cellIsVisible As
Boolean)
           MyBase.Edit(source, rowNum, bounds, [readOnly], instantText,
cellIsVisible)
       End Sub

Would this be a good place to fire/raise an event? When is this called? Is
it called after the text is changed (so instantText will contain the changed
value)?

Thank you for your help.

Kevin