How to refresh DataGrid data without freezing and over-loading?

Question

.NET

Good evening everyone! I am developing a program to view complete information about the processes on the computer:


Automatic updating of the DataGrid is implemented in a separate thread by binding to the Processes property in the view model (I try to stick to MVVM) that implements the INotifyPropertyChanged interface:

public class MainVM : INotifyPropertyChanged
    {
        public MainVM()
        {
            // We perform the update operation in a separate thread
            Task.Run(() =>
            {
                // Endless cycle
                while (true)
                {
                    Processes = Process.GetProcesses().ToList();
                    Thread.Sleep(4000); // Updating every 4 seconds
                }
            });
        }
        private List<Process> _processes;
        public List<Process> Processes
        {
            get { return _processes; }
            set
            {
                _processes = value;
                OnPropertyChanged("Processes");
            }
        }
        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

XAML markup for DataGrid:

<DataGrid Name="processesDataGrid" Grid.Row="1" AutoGenerateColumns="False" 
                  ItemsSource="{Binding Processes, UpdateSourceTrigger=PropertyChanged}">
            <DataGrid.RowStyle>
                <Style TargetType="DataGridRow">
                    <Style.Triggers>
                        <DataTrigger Binding="{Binding MainModule.FileVersionInfo.CompanyName}" Value="Microsoft Corporation">
                            <Setter Property="Background" Value="HotPink"/>
                        </DataTrigger>
                    </Style.Triggers>
                </Style>
            </DataGrid.RowStyle>
            <DataGrid.Columns>
                <DataGridTextColumn Header="ID" Binding="{Binding Id}"/>
                <DataGridTextColumn Header="Name" Binding="{Binding ProcessName}"/>
                <DataGridTextColumn Header="Title" Binding="{Binding MainWindowTitle}"/>
                <DataGridTextColumn Header="Memory Size" Binding="{Binding PagedMemorySize64}"/>
                <DataGridTextColumn Header="Threads count" Binding="{Binding Threads.Count}"/>
                <DataGridTextColumn Header="Company" Binding="{Binding MainModule.FileVersionInfo.CompanyName}"/>
                <DataGridTextColumn Header="Description" Binding="{Binding MainModule.FileVersionInfo.FileDescription}"/>
                <DataGridTextColumn Header="Copyright" Binding="{Binding MainModule.FileVersionInfo.LegalCopyright}"/>
            </DataGrid.Columns>
        </DataGrid>

The list of processes is updated every 4 seconds, this is indicated in the view model:

while (true)
{
     Processes = Process.GetProcesses().ToList();
     Thread.Sleep(4000); // Updating every 4 seconds
}

But, the fact is that the application is very slow, and freezes every 4 seconds. It becomes difficult to use. Yes, I understand that this is all due to the load, but in the standard Windows task manager it still works without freezes. Therefore, I'm looking for a way to make updating the DataGrid as smooth as possible.
Thanks in advance.

Answer 1

I do not think that all data is updated in the dispatcher at once, and not by event. Make instead List Observablecollection and change the state of a specific object and you will not need to update the entire list in 4 seconds

Answer 2

Using the ToList () method, you suck out all the objects, try manually using Select to take only those that are needed.