CODEWITHSUNDEEP
c#wpf
Grey Walker
Grey Walker

Reputation: 125

WPF application DispatchTimer updates every two seconds instead of one

I am trying to call a method every second using DispatcherTimer(); this works fine when updating the timer, however whenever I try to update any UI Emements in the method the timer seems to tick every 2 seconds instead of every second and the more UI elements I add to update increases the tick time, also the window cant be dragged around the screen between the ticks.

How can I get the time to update every second correctly?

I'm querying a web api to receive data. I wonder could this be the problem?

private void btnConnect_Click(object sender, RoutedEventArgs e)
{ 
    var dispatcherTimer = new DispatcherTimer();
    dispatcherTimer.Tick += new EventHandler(DispatcherTimer_Tick);
    dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
    dispatcherTimer.Start();
}        

private void DispatcherTimer_Tick(object sender, EventArgs e)
{            
    // Updating the Label which displays the current second
    lblTime.Content = DateTime.Now.ToString("HH:mm:ss");

    lblSizeBTC_USD.Content = "SIZE " + Api.GetProductTicker(productId).Result.size;            

    // Forcing the CommandManager to raise the RequerySuggested event
    CommandManager.InvalidateRequerySuggested();
}

Method calling the web api

public static async Task<ProductTicker> GetProductTicker(string productId)
{
    string ts = GetNonce();
    string method = "/products/" + productId + "/ticker";
    string sig = GetSignature(ts, "GET", method, string.Empty);
    ProductTicker productTicker;

    using (var client = new HttpClient())
    {
        client.BaseAddress = new Uri(baseURL);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        client.DefaultRequestHeaders.Add("CB-ACCESS-KEY", apiKey);
        client.DefaultRequestHeaders.Add("CB-ACCESS-SIGN", sig);
        client.DefaultRequestHeaders.Add("CB-ACCESS-TIMESTAMP", ts);
        client.DefaultRequestHeaders.Add("CB-ACCESS-PASSPHRASE", passphrase);
        client.DefaultRequestHeaders.Add("User-Agent", userAgent);
        HttpResponseMessage response = client.GetAsync(method).Result;
        response.EnsureSuccessStatusCode();

        string json = await response.Content.ReadAsStringAsync();
        productTicker = JsonConvert.DeserializeObject<ProductTicker>(json);
    }

    return productTicker;
}

Upvotes: 0

Views: 460

Answers (1)

Grey Walker
Grey Walker

Reputation: 125

Clemens was indeed correct the working updated code is below. The solution was to make the DispatcherTimer_Tick method async and to await the GetProductTicker call:

private async void DispatcherTimer_Tick(object sender, EventArgs e)
{            
    // Updating the Label which displays the current second
    lblTime.Content = DateTime.Now.ToString("HH:mm:ss");

    var productTicker = await Api.GetProductTicker(productId);

    lblSizeBTC_USD.Content = "SIZE " + productTicker.size;        

    // Forcing the CommandManager to raise the RequerySuggested event
    CommandManager.InvalidateRequerySuggested();
}

Upvotes: 1

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