I have xamdatagrid and within this grid there is a column which is of type combobox. Now based upon certain condition when I change the selection of the comobobox a new record should get added within the Grid. Please suggest if I need to add trigger to the combobox upon selectionchanged and raise and event in that case I would need the index of currently grid row selected and index of combov=box selected item.

Please advise how can achive the above.

Below is the xaml code:

<UserControl x:Class="DLVR.IndividualPositionReport.Visualisation.Views.AggreagteCalcParamCollectionView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:local="clr-namespace:DLVR.IndividualPositionReport.Visualisation.Views"
xmlns:bmg="clr-namespace:DLVR.IndividualPositionReport.Visualisation.BenchmarkGrid"
xmlns:bm="clr-namespace:DLVR.IndividualPositionReport.Visualisation.CompensationBlock"
xmlns:vp="clr-namespace:DLVR.Shared.BaseClasses.VisualisationParameters;assembly=DLVR.Shared"
xmlns:idp="http://infragistics.com/DataPresenter"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:ig="http://infragistics.com/Editors"
mc:Ignorable="d" 
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Grid.Resources>
<Style x:Key="textField" TargetType="{x:Type idp:CellValuePresenter}">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<ItemsControl ItemsSource="{Binding Path=DataContext.DataItem.Value.Parameters,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type idp:CellValuePresenter}}}" DataContext="{Binding Value,Mode=OneWay}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction CommandParameter="{Binding Path=DataContext.DataItem}" Command="{Binding DataContext.SelectChangeCommand, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type idp:CellValuePresenter}}}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<ItemsControl.ItemTemplate>
<DataTemplate>
<ig:XamTextEditor Value="{Binding Value}">
<ig:XamTextEditor.Template>
<ControlTemplate>
<TextBlock Text="{Binding Value,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"></TextBlock>
</ControlTemplate>
</ig:XamTextEditor.Template>
<ig:XamTextEditor.EditTemplate>
<ControlTemplate>
<TextBox Text="{Binding Value, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"></TextBox>
</ControlTemplate>
</ig:XamTextEditor.EditTemplate>
</ig:XamTextEditor>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel></StackPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel> 
</ItemsControl>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="combo" TargetType="{x:Type idp:CellValuePresenter}">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<ComboBox ItemsSource="{Binding Path=DataContext.DataItem.Options,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type idp:CellValuePresenter}}}"
DisplayMemberPath="Label"
SelectedItem="{Binding Path=DataContext.DataItem.Value,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type idp:CellValuePresenter}}}">

</ComboBox>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
<StackPanel Grid.Row="0" Orientation="Horizontal" HorizontalAlignment="Center">
<Button Content="Add Row" Width="100" Margin="0,0,20,0" Command="{Binding AddNewRowCommand}"></Button>
<Button Content="Delete Row(s)" Width="100" Command="{Binding DeleteRowCommand}"></Button>
</StackPanel>
<StackPanel Orientation="Horizontal" Grid.Row="1">
<CheckBox IsChecked="{Binding IsVarianceChecked}" Width="Auto" Command="{Binding VarianceCommand}"/>
<TextBlock Text="Show variance from Sponsor" Width="Auto"/>
</StackPanel>
<idp:XamDataGrid x:Name="td" Grid.Row="2" 
DataSource="{Binding FilteredCalcParameter,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
SelectedDataItems="{Binding SelectedRows,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
SelectedDataItemsScope="RecordsOnly"
IsSynchronizedWithCurrentItem="True">
<idp:XamDataGrid.FieldLayoutSettings>
<idp:FieldLayoutSettings AutoGenerateFields="False"
></idp:FieldLayoutSettings>
</idp:XamDataGrid.FieldLayoutSettings>
<idp:XamDataGrid.FieldLayouts>
<idp:FieldLayout>
<idp:FieldLayout.Fields>
<idp:UnboundField BindingPath="Value" Label="Calculation" CellValuePresenterStyle="{StaticResource ResourceKey=combo}">
</idp:UnboundField>
<idp:UnboundField BindingPath="Value" Label="Parameter (where applicable)" BindingMode="TwoWay" CellValuePresenterStyle="{StaticResource ResourceKey=textField}">
</idp:UnboundField>
</idp:FieldLayout.Fields>
</idp:FieldLayout>
</idp:XamDataGrid.FieldLayouts>
</idp:XamDataGrid>
</Grid>
</UserControl>