CODEWITHSUNDEEP
c#xamarinxamarin.formsasync-awaittask
Alan2
Alan2

Reputation: 24572

When I call a method with Task.Run() does it have to be an async method?

My code looks like this:

    async public Task Btn(int pts)
    {
        switch (Settings.mode)
        {
            case MO.Assign:
            case MO.Learn:
                break;
            case MO.Quiz:
                await Task.Run(() => App.DB.IncrementPoints(phrase, 1));
                await Task.Delay(250);
                break;
            case MO.Practice:
                Device.BeginInvokeOnMainThread(() =>
                {
                    vm.Points = new String('☆', phrase.Points + pts);
                });
                await Task.Run(() =>
                {
                    App.DB.IncrementPoints(phrase, pts);
                    App.DB.IncrementHistory(HIST.Views);
                });
                await Task.Delay(250);
                break;
        }
        App.selectedPhrases = null;
        timer2Seconds = 2;
    }


    public void IncrementPoints(Phrase phrase, int pts)
    {
        lock (l)
        {
            db2.Execute("UPDATE phrase SET Points = Points + " + pts +
                        " WHERE PhraseId = '" + phrase.PhraseId + "'");
        }
    }

I am a bit confused with Task.Run and await. First of all I want this to update the screen:

vm.Points = new String('☆', phrase.Points + pts);

Then I want the database to be updated and then there to be a delay of 250ms.

But is it okay that my method IncrementPoints is not an async method?

Upvotes: 0

Views: 80

Answers (1)

Sweeper
Sweeper

Reputation: 271175

I am not exactly sure what you want to do, but to answer your question:

But is it okay that my method IncrementPoints is not an async method?

Yes, it's ok, and that is also exactly one of the purposes of Task.Run. You can use Task.Run to turn synchronous operations to awaitable async operations. So you are supposed to put non-async methods in the lambda. If IncrementPoints were async, you wouldn't need Task.Run, because you can just do:

await IncrementPoints(...);

Your code should just be something like this:

vm.Points = new String('☆', phrase.Points + pts);

await Task.Run(() =>
{
    App.DB.IncrementPoints(phrase, pts);
    App.DB.IncrementHistory(HIST.Views);
});
await Task.Delay(250);

Upvotes: 3

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