Updating weather using Threading

[Etienne_123]

Hi people I'm using a web service to display the current weather on my main interface. At the moment I have to click a button everytime I want to update the weather, and while this is updating, my interface stalls for however long it takes to update which is usually 5 seconds. What I want to know is, is there a way to have this running on a separate thread without clicking a button and have it update continuously while still being able to work with the main interface? Here is the code I use to update the current temperature:

string strTemperature = "";

GlobalWeatherService.GlobalWeatherSoapClient proxy = new aXYZ.GlobalWeatherService.GlobalWeatherSoapClient("GlobalWeatherSoap12", "http://www.webservicex.net/globalweather.asmx");

string weatherXml = proxy.GetWeather("Port Elizabeth", "South Africa");

StringReader reader = new StringReader(weatherXml);
XmlReader readerXml = XmlReader.Create(reader);
XmlDocument weatherXmlDoc = new XmlDocument();
weatherXmlDoc.Load(readerXml);

for (int i = 0; i < weatherXmlDoc.ChildNodes.Count; i++)
{
for (int j = 0; j < weatherXmlDoc.ChildNodes[i].ChildNodes.Count; j++)
{
if (weatherXmlDoc.ChildNodes[i].ChildNodes[j].Name == "Temperature")
strTemperature = weatherXmlDoc.ChildNodes[i].ChildNodes[j].InnerText;
}
}

lblTemperature.Content = strTemperature;

[kstls]

You can indeed use a thread to handle this. Here's a nice beginners guide about threading here on Codeproject: Beginners Guide To Threading In .NET Part 1 of n

[Etienne_123]

Thanks. I'll go through that now. I tried using a DispatcherTimer like in the following code:

        // Create a Timer with a Normal Priority
        DispatcherTimer \_timer = new DispatcherTimer(DispatcherPriority.Normal);

        // Set the Interval to 2 seconds
        \_timer.Interval = TimeSpan.FromMilliseconds(2000);

        // Set the callback to just show the time ticking away
        // NOTE: We are using a control so this has to run on 
        // the UI thread
        \_timer.Tick += new EventHandler(delegate(object s, EventArgs a)
        {
            UpdateWeather();
        });

        // Start the timer
        \_timer.Start();

I've tried about 4 different ways of using the Dispatcher, but no matter what I try, my UI keeps freezing while it's doing UpdateWeather. Can it be because I call this Timer from my form_Loaded event??

[Luc Pattyn]

Hi, you probably need this[^]. BTW: does the weather really change every 5 seconds where you live? :)

Luc Pattyn [Forum Guidelines] [My Articles]

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[Mycroft Holmes]

I was going to lend him some of my threads if he can order me a cold snap for Tuesday.

Never underestimate the power of human stupidity RAH

[Etienne_123]

Okay it seems to work with the BackgroundWorker.

    backgroundMessageGetter.DoWork += new DoWorkEventHandler(backgroundMessageGetter\_DoWork);
    backgroundMessageGetter.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundMessageGetter\_RunWorkerCompleted);
    backgroundMessageGetter.ProgressChanged += new ProgressChangedEventHandler(backgroundMessageGetter\_ProgressChanged);
    backgroundMessageGetter.WorkerReportsProgress = true;
    backgroundMessageGetter.RunWorkerAsync(this);

    void backgroundMessageGetter\_DoWork(object sender, DoWorkEventArgs e)
    {
        try
        {
            while (true)
            {
                GlobalWeatherService.GlobalWeatherSoapClient proxy = new aXYZ.GlobalWeatherService.GlobalWeatherSoapClient("GlobalWeatherSoap12",
                    "http://www.webservicex.net/globalweather.asmx");

                string weatherXml = proxy.GetWeather("Port Elizabeth", "South Africa");
                //some other processing

                backgroundMessageGetter.ReportProgress(0);
                Thread.Sleep(2000);
            }
        }
        catch (Exception error)
        {
            System.Windows.MessageBox.Show(error.Message);
        }
    }

    void backgroundMessageGetter\_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        //update UI
    }

modified on Saturday, November 14, 2009 8:42 AM

[Luc Pattyn]

No problem. Is a 5-second cold snap within an otherwise hot November day sufficient? :)

Luc Pattyn [Forum Guidelines] [My Articles]

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I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

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