David,

It is not a nice solution, however we have the method for this on our
website (which is a VB Net website so no C# however it should be clear the
difference is almost less than nothing)

http://www.vb-tips.com/default.aspx?ID=30d9d2fd-9f10-4928-b7c8-1def3152436f

I hope this helps,

Cor

Yes, but you will need to make the column that displays the calculated
value a "nonCalculated column, otherwise (I think) the calculation
will be done twice if you use the example:

Use the ColumnChanged event to calculate the value.  Here is an
example of the ColumnChanged event from the VS 2005 help files (VS
2003 will be the same).  

You may have to refresh the row to make the new value display in the
column you calculated.

private static void Column_Changed(object sender,
DataColumnChangeEventArgs e )
{
   Console.WriteLine("Column_Changed Event: name={0}; Column={1};
original name={2}",
       e.Row["name"], e.Column.ColumnName, e.Row["name",
DataRowVersion.Original]);
}

HTH

Otis Mukinfus
http://www.otismukinfus.com
http://www.tomchilders.com

David:

The problem is that the Expression isn't calclated until after the edit is
complete. So when you're making the change in the row in the grid, it's
still in Edit mode.  by calling EndEdit on the row, or EndCurrentEdit on the
bindingManager/context that the grid's bound to, the refresh will take
place.  To facilitate this, you can check for the ColumnChanging or the
CurrentCellChanging. Depending on how many expressions you have in the
table, you may want to trap different events.  In this example, I trap
CurrentCellChange and just end the edit, which causes the Expression to
recompute.  You could add functionality to check for your specific column or
depending on the column, take a different course  of action.  The main thing
to understand though is why it's not updating and that's b/c the row is
still in Edit mode (which for example, as far as its concerned, means you
could undo the changes you just made) so it won't change until you've
finished the edit.  Here's code that will do it for you:

private void dataGridView1_CurrentCellChanged(object sender, EventArgs e)

{

if (dataGridView1.CurrentRow != null && dataGridView1.CurrentRow.Index >= 0)

{

dt.Rows[dataGridView1.CurrentRow.Index].EndEdit();

}

}