How to stop or reduce the RAM usage as the Wpf Datagrid is Continuosly being updated by background Worker?

Question

Hi,
I am developing a packet sniffer application, I am getting a packets from adapter and am updating the information in the Wpf Datagrid using a Background worker. it is a continuous process. So if run this application for hours, after 5 or 6 hours I am getting
a "Sytem.OutofMemoryException" as the RAM being full. Now my requirement is, the usage of RAM should have a some limit(suppose 750MB) for my application, once application reaches this, the usage of RAM should not increase and at the same time I should
not get "OutofmemoryException". I mean application should free cached memory of starting Rows of DataGrid, means I should not display the initial Rows and I should display the latest entries. how can I achieve this?
thanks,
EDIT:
Here I am using DataGrid.Items.Add() method to add the entries into the datagrid.
How can I change my code to Observablecollection items now?

Answer 1

You could remove entries from the ItemsSource collection of the DataGrid once the number of items reaches a certain threshold of items.
If you for example use an ObservableCollection<T> as the ItemsSource of the DataGrid you could handle its CollectionChanged event and remove the oldest item when there are a total of say over 5000 (you may of course increase this value in your
partiuclar application of you require to be able to display more than 5000 items in the DataGrid) items in it. This will make sure that there will never by any more than 5000 items kept in memory:
const int MaxCount = 5000;
public MainWindow()
InitializeComponent();
ObservableCollection<string> collection = new ObservableCollection<string>();
collection.CollectionChanged += (ss, ee) =>
if (collection.Count > MaxCount)
collection.RemoveAt(0);
yourDataGrid.ItemsSource = collection;
Since there is no good way to determine exactly how much physical memory the objects in the ObservableCollection<T> occupy so you better choose a maximum
number of items to be kept in memory (like MaxCount = 5000 in the sample code above) and then remove the oldest one when the number of items reach this maximum.
Hope that helps.
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