CODEWITHSUNDEEP
c#multithreadingevents
Bob Horn
Bob Horn

Reputation: 34297

Updating ObservableCollection on dispatcher thread causes UI to freeze

When updating my ObservableCollection, I was getting this error:

This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread.

Using this answer as a guide, I thought this code would work:

private ObservableCollection<string> _userMessages = new ObservableCollection<string>();

public void AddUserMessage(string message)
{
    lock (_locker)
    {
        Action action = () =>
        {
            this._userMessages.Add(message);
        };

        Application.Current.Dispatcher.Invoke(DispatcherPriority.Normal, action);
    }
}

However, my UI now freezes when calling Dispatcher.Invoke(). What am I doing incorrectly?

Note: I needed to do this because I'm (sometimes) updating my ObservableCollection from events.

Upvotes: 0

Views: 1934

Answers (1)

Vyacheslav Volkov
Vyacheslav Volkov

Reputation: 4742

Try this:

Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Normal, action);

You invoke your action synchronously and it causes UI to freeze.

Upvotes: 1

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