CODEWITHSUNDEEP
c#wpfxamltimerdatagrid
CBreeze
CBreeze

Reputation: 2965

Periodically Refreshing a DataGrid C# WPF

I have a DataGrid in C# WPF that is filled with Employees. Essentially I need to read from a Database periodically as when the Employees enter a building, a field is modified. I am having a few issues with the best way to approach this situation. First, this is how I define my DataGrid;

public ICollectionView FilteredView { get; set; }
public ObservableCollection<EmployeeModel> Employees {get; set; }

private void OnPageLoad(object sender, RoutedEventArgs e)
{
    var _employeeDataService = new EmployeeDataService();
    Employees = _employeeDataService.HandleEmployeeSelect();
    FilteredView = CollectionViewSource.GetDefaultView(Employees);
    dataGrid.ItemsSource = FilteredView;
    DataContext = this;

    System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
    dispatcherTimer.Tick += new EventHandler(TimerTick);
    dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
    dispatcherTimer.Start();
}

Essentially the TimerTick method that currently fires every second simply calls this method again, so that the entire table is retrieved from the database and the appropriate fields (whether the user is in the building or not is updated).

This method as I said has a number of issues. Firstly, it doesn't look good. As the DataGrid is constantly refreshing, any actions that the user takes on the grid is slow and the highlighting of each row is distorted.

Secondly I use methods to filter the DataGrid. The user is able to type in a name of an Employee and the DataGrid is filtered accordingly. Once again because the DataGrid is refreshed every second, it is literally impossible to filter on the DataGrid because everything the user types is undone every second.

I understand I could potentially refresh the DataGrid say every minute which would be much improved, however it is still no where near ideal and I am sure there is a better solution. How can I improve this solution so that the updating of the DataGrid is a lot more subtle and unknown to the user?

Upvotes: 1

Views: 671

Answers (1)

Kolky
Kolky

Reputation: 2977

Instead of updating the whole collection, only add, move or remove items from the ObservableCollection that are actually different or changed. It implements INotifyCollectionChanged and INotifyPropertyChanged which will notify the DataGrid.

Upvotes: 1

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