WPF grid not refreshing on second process - wpf

Question

I am working with WPF + some custom templates/extensions, MVVM architecture. I have a grid that displays records. If user selects one or more rows and clicks 'process' the records will be marked as inactive in the database. Once this completes the grid refreshes and the inactivated records no longer appear. However if the user selects another records and clicks 'process' the record is marked inactive in the database but the grid does not refresh. I have it set up almost exactly the same on another page and it works. When I debug the NotifyPropertyChanged event is triggered both times. Why is the message not getting to the grid the second time (or any time after that)?
here is my ViewModel and View (drastically cut down but hopefully has enough info)
using System.Collections.Generic;
using System;
using CoreApi;
using System.Collections;
using System.Windows.Input;
using Microsoft.Practices.Composite.Presentation.Commands;
using System.Windows;
public class MembershipCloseoutAgreementsViewModel : PropertyChangedBase, IMembershipCloseoutPartViewModel
{
public MembershipCloseoutAgreementsViewModel()
{
CloseAgreements = new DelegateCommand<object>((p) => CloseSelectedAgreements());
}
public void Initialize(PartInitializationInfo initializationInfo)
{
if (_backgroundWorker == null)
{
_backgroundWorker = new BackgroundWorker();
_backgroundWorker.DoWork += new DoWorkEventHandler(ProcessAgreements);
_backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(OnProcessCompleted);
}
}
private void CloseSelectedAgreements()
{
if (SelectedAgreements != null && SelectedAgreements.Count > 0)
{
Mouse.OverrideCursor = Cursors.Wait;
IsProcessing = true;
IsProcessEnabled = false;
IsGridEnabled = false;
_backgroundWorker.RunWorkerAsync();
}
}
private void ProcessAgreements(object sender, DoWorkEventArgs e)
{
if (numEAgreements > 0)
{
//this method will create and send requests
var success = ProcessEAgreementRequest(numEAgreements, SelectedAgreements);
...
//I've tried putting NotifyPropertyChanged(() => PersonAgreements) here and inside the "ProcessEAgreementRequest" method
}
/**Refresh the grid**/
if (PersOrgNbr.Item1 == "PERS")
{
PersonAgreements = AgreementDetailProvider.GetAgreementDetails(PersOrgNbr);
//I've tried putting NotifyPropertyChanged(() => PersonAgreements) here
}
else
{
PersonAgreements = AgreementDetailProvider.GetAgreementDetails(PersOrgNbr, MemberNumber.ToString(), AccountList);
//I've tried putting NotifyPropertyChanged(() => PersonAgreements) here
}
NotifyPropertyChanged(() => PersonAgreements);
}
private void OnProcessCompleted(object s, RunWorkerCompletedEventArgs e1)
{
IsProcessing = false;
IsProcessEnabled = false;
IsGridEnabled = true;
Mouse.OverrideCursor = null;
}
<ListView Grid.Row="2" x:Name="AgreementsList"
HorizontalAlignment="Right"
ItemsSource="{Binding PersonAgreements}"
IsEnabled="{Binding IsGridEnabled}"
ScrollViewer.HorizontalScrollBarVisibility="Disabled"
ScrollViewer.VerticalScrollBarVisibility="Auto">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<ei:ChangePropertyAction TargetObject="{Binding Mode=OneWay}"
PropertyName="SelectedItems"
Value="{Binding Path=SelectedItems, ElementName=AgreementsList}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<ListView.View>
<GridView>
<GridViewColumn Header="Agreement #" Width="110" DisplayMemberBinding="{Binding AgreementNumber}"></GridViewColumn>
<GridViewColumn Header="Pers/Org#" Width="110" DisplayMemberBinding="{Binding AssociatedPersOrgNumber}"></GridViewColumn>
<GridViewColumn Header="Description" Width="575" DisplayMemberBinding="{Binding UI_Description}"></GridViewColumn>
</GridView>
</ListView.View>
</ListView>
'''

Answer 1

The issue was with the list not refreshing correctly. Instead of setting the list as a property I created a brand new list every time the code re-queried the database. When the list was a property it was persisting across all the calls and providing odd values. Either no change, or it appended more data. I believe this is lists are a 'reference' type as opposed to a 'value' type. Sneaky.