Question

public class SyncHelper
{
    private LiveConnectClient client;
    public event EventHandler SyncStarted;
    public event EventHandler SyncCompleted;

    public SyncHelper(LiveConnectClient client)
    {
        this.client = client;
    }

    public void TrySync()
    {
        Debug.WriteLine("Beginning sync");
        OnSyncStarted();
        client.GetCompleted += OnGetCompleted;
        client.GetAsync("me/skydrive/files");
    }

    private void OnGetCompleted(object sender, LiveOperationCompletedEventArgs e)
    {
        Thread.Sleep(10000);
        Debug.WriteLine("Get Completed");
        client.GetCompleted -= OnGetCompleted;
        OnSyncCompleted();
        Debug.WriteLine("Sync completed");
    }

    private void OnSyncStarted()
    {
        if (SyncStarted != null)
            SyncStarted(this, new EventArgs());
    }

    private void OnSyncCompleted()
    {
        if (SyncCompleted != null)
            SyncCompleted(this, new EventArgs());
    }
}

The function OnGetCompleted is being called in the UI thread and the UI is unresponsive. From whatever I know, I thought these callbacks would work in a different thread and we would have to use the displatcher to post it to the UI thread. Any thoughts? Help!

Answer 1

The GetAsync call is likely using a background thread to do the actual fetch, but then it’s trying to help you by calling the Completed callback in the original thread context so you don’t have to use a Dispatcher.

Why are you putting in a Sleep(10000) anyway? The callback says “hey, I’m done”. At that point you should update the UI if you want. If you need to do further processing that takes significant time, spawn a background thread, threadpool task or use another asynchronous call with another callback.