CODEWITHSUNDEEP
c#wpfmvvm
user547794
user547794

Reputation: 14511

ObservableCollection updating from one method but not another

I have a method that updates my observableCollection

public void UpdateBeat()
{
    SequenceCollection = new ObservableCollection<Sequence>();

    Random random = new Random();
    int randomNumber = random.Next(0, 100);

    SequenceCollection.Add(new Sequence(1, 2));            
}

I have 2 different methods fired from events - the view updates from 1 of the methods but not the other.

//Does not work
private void BsOnUpdateStep(object sender, EventArgs eventArgs)
{
    Console.WriteLine("BS Update");
    UpdateBeat();
}

//Works
void total_AudioAvailable(object sender, AsioAudioAvailableEventArgs e)
{
    Console.WriteLine("ASIO Written");
    UpdateBeat();
}

I have no idea what the difference could be here. The only thing I can tell is that the 1st method fires more often than the 2nd. I cannot get the 2nd to work at all.

Upvotes: 0

Views: 122

Answers (2)

George Mavritsakis
George Mavritsakis

Reputation: 7083

I suppose your calls to UpdateBeat are from different threads but ObservableCollection is not thread safe, that is why -probably- you have such strange results.

You should look for an concurrent ObservableCollection.

One such implementation can be found here: http://www.codeproject.com/Tips/414407/Thread-Safe-Improvement-for-ObservableCollection

Upvotes: 2

Enigmativity
Enigmativity

Reputation: 117064

Try this:

private SequenceCollection = new ObservableCollection<Sequence>();
Random random = new Random();

public void UpdateBeat()
{
    int randomNumber = random.Next(0, 100);

    SequenceCollection.Add(new Sequence(1, 2));            
}

I put the Random instantiation outside of the method too as you should only instantiate this once to get a proper stream of random numbers.

Upvotes: 1

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