WPF Backgroundwork er call method on DoWork event - wpf

Question

I have a BackgroundWorker on my WPF UserControl.
private readonly BackgroundWorker worker = new BackgroundWorker();
public ucCustomer()
{
InitializeComponent();
worker.DoWork += worker_DoWork;
worker.RunWorkerCompleted += worker_RunWorkerCompleted;
}
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
// run all background tasks here
System.Threading.Thread.Sleep(10000);
}
private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//update ui once worker complete his work
}
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
worker.RunWorkerAsync();
}
Above code is work, the UI is response when the task is working, but if i change the worker_DoWork() to
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
// run all background tasks here
Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Background,
new Action(() => {
gridDataBind(); //A long data-mining task,using Dispatcher.Invoke() to access UI.
}));
}
private void gridDataBind()
{
SnEntities sn = new SnEntities();
var customers = from c in sn.Customer select c;
dgCustomer.ItemsSource = customers.ToList();
}
The UI is freeze until the task is end.
Is it any solution?
Thanks you.

Answer 1

Try setting the ItemsSource like below code:
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
// run all background tasks here
e.Result = gridDataBind(); //A long data-mining task.
}
private IList<Customer> gridDataBind()
{
SnEntities sn = new SnEntities();
var customers = from c in sn.Customer select c;
return customers.ToList();
}
private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
var customers = e.Result as IList<Customer>;
ObservableCollection<Customer> gridItemsSource = new ObservableCollection<Customer>();
Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Background,
new Action(() =>
{
dgCustomer.ItemsSource = gridItemsSource;
}));
foreach(var customer in customers)
{
Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Background,
new Action(() =>
{
gridItemsSource.Add(customer);
}));
}
}

Answer 2

Store your data in e.result at worker_DoWork and update UI at the worker_RunWorkerCompleted.
in that case UI will be free when data will coming from database.

Answer 3

Try this, it should help you
Application.Current.Dispatcher.BeginInvoke(
DispatcherPriority.Background,
new Action(() => gridDataBind();));