Silverlight 4 Multithread
I'm trying to update my Silverlight 4 UI approx every 1/2 second with new data. I've hooked into a WCF service using net.tcp binding and issuing callbacks from the se开发者_如何学Gorver. To make sure I get the data from the service as quickly as possible I've started up my proxy on a backround worker inside of my Silverlight App.
My question is, how do I get the results from the callback and update the ObservableCollection that is bound to a datagird? I've tried a number of different ways and keep getting the dreaded cross-thread error.
Use the Dispatcher
BeginInvoke
. For example:-
private void MyCallback(object sender, SomeArgsClass e)
{
// perhaps some extraction of a payload or something
Deployment.Current.Dispatcher.BeginInvoke( () =>
{
// Code you need to run on the UI thread.
});
// Note code may or may not exit here before code above has completed.
// So be careful with disposable types etc.
}
There are several approaches you can take:
use
Deployment.Current.Dispatcher
from the background thread, and do a Deployment.Current.Dispatcher.CheckAccess() call on itpass the dispatcher from the UI component that starts the background thread, and use that handle to perform the CheckAccess() call
this is my preferred option: pass a delegate (callback) to the background thread, when it has new data it calls that delegate, and that delegate lives within the UI control - it can then use the Dispatcher available on the UI control
The pattern for this sort of thing is:
private void DoMyUIUpdate(List<object> updates)
{
if (Deployment.Current.Dispatcher.CheckAccess())
{
//do my work, update the UI
}
else
Deployment.Current.Dispatcher.BeginInvoke(new Action<List<object>>(DoMyUIUpdate), updates);
}
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