Hi, So I have a datagrid, bound to BindingList<Instrument> from my viewmodel like so:

<Grid>

<igWPF:XamDataGrid Name="SecurityBlotterGrid"

 Height="Auto"

  DataSource="{Binding InstrumentList}"

ExecutingCommand="SecurityBlotterGrid_ExecutingCommand"

  SelectedDataItems ="{Binding selectedInstrumentList, Mode=TwoWay}"

SelectedDataItemsScope ="RecordsOnly">

<igWPF:XamDataGrid.Resources>

<Style TargetType="{x:Type igWPF:CellValuePresenter}">

<Setter Property="BorderThickness" Value="0,0,1,1"/>

<Setter Property="BorderBrush" Value="Transparent"/>

<Setter Property="BorderHoverBrush" Value="Transparent"/>

</Style>

</igWPF:XamDataGrid.Resources>

<igWPF:XamDataGrid.FieldLayoutSettings>

<igWPF:FieldLayoutSettings AllowClipboardOperations="All"

 CopyFieldLabelsToClipboard="True"

 HeaderPrefixAreaDisplayMode="FieldChooserButton"

 AutoGenerateFields="False"

 SummaryEvaluationMode="Auto"

FilterUIType="FilterRecord"

SelectionTypeRecord="Extended"/>

</igWPF:XamDataGrid.FieldLayoutSettings>

<igWPF:XamDataGrid.FieldSettings>

<igWPF:FieldSettings AllowRecordFiltering="True"

AllowSummaries="true" SummaryUIType="MultiSelect"

CellClickAction="SelectRecord"/>

</igWPF:XamDataGrid.FieldSettings>

<igWPF:XamDataGrid.FieldLayouts>

<igWPF:FieldLayout IsDefault="True">

<igWPF:FieldLayout.Fields>

[...]

and then closing tags for all.

Now, the grid populates just fine, but what I need to be able to do is have the user select one ore more records from the grid, and use those records to determine the data that shows up on a completely different viewModel.

The cleanest way I thought to achieve this was to use the part that says SelectedDataItems={Binding selectedInstrumentList, mode=TwoWay}"

and of course I have a selectedInstrumentList in my viewmodel of type BindingList<Instrument>

yet when I try to do this:

selectedInstrumentList.ListChanged += new ListChangedEventHandler(selectedInstrumentList_ListChanged);

the ListChangedEvent never occurs.

Next I tried capturing it from the codebehind which is kind of sloppy, but I want to get it done:

SecurityBlotterGrid.SelectedItemsChanged += new EventHandler<Infragistics.Windows.DataPresenter.Events.SelectedItemsChangedEventArgs>(SecurityBlotterGrid_SelectedItemsChanged);

void SecurityBlotterGrid_SelectedItemsChanged(object sender, Infragistics.Windows.DataPresenter.Events.SelectedItemsChangedEventArgs e)

        {

var grid = (XamDataGrid)sender;

var instrumentArray = grid.SelectedDataItems;

if (instrumentArray != null)

            {

var tempBinding = new BindingList<InstrumentSummary>();

                ViewModel.selectedInstrumentList.Clear();

foreach (var instrument in instrumentArray)

                {

ViewModel.selectedInstrumentList.Add((

InstrumentSummary)instrument);

                }

            }

        }

but grid.SelectedDataItems seems to always have the previous selected item, not the one(s) i'm currently trying to select.  Furthermore I have to do viewModel.selectedInstrumentList.Add((InstrumentSummary)instrument) one-at-a-time because if I try to do it en masse, the listchanged event doesn't fire on the viewmodel. 

can you please explain to me what I am doing wrong?

Thanks