How to check every 30seconds with dispatchertimer without affect the UI in c#?

Question

I hav tried the below code for checking reports from server in every 30seconds,but after 30seconds tick,The application hangs for several seconds.How to avoid the Hanging problem. The below code am tried,what change want to given in this?

System.Windows.Threading.DispatcherTimer dispatcherTimer2 = new System.Windows.Threading.DispatcherTimer();
 dispatcherTimer2.Tick += new EventHandler(dispatcherTimer2_Tick);
 dispatcherTimer2.Interval = new TimeSpan(0, 0, 30);


Public void dispatcherTimer2_Tick(object sender, EventArgs e)
{
   dispatcherTimer2.start();
    //code for function call autoreport();
}

What does that `autoreport` does? Does it works with UI or non UI elements? If latter, you don't need a `DispatcherTimer` you can use `System.Timers.Timer` — Sriram Sakthivel, Feb 20 '15 at 06:16
@SriramSakthivel: The autoreport works with UI,am used the Syatem.Timer.Timer, that time also hangs several seconds — NvadeepKumar, Feb 20 '15 at 06:20

Dima Korn · Accepted Answer · 2015-02-20T06:16:40.750

4

DispatcherTimer callback is executed on main UI thread and blocks it. Use System.Threading.Timer and if you need to update user interface from timer callback use one of Dispatcher.Invoke overloads. In code something like this

public partial class MainWindow : Window
{
    System.Threading.Timer timer;
    public MainWindow()
    {
        InitializeComponent();
        timer = new System.Threading.Timer(OnCallBack, null, 0, 30 * 1000);
    }


    private void OnCallBack(object state)
    {
        //code to check report 
        Dispatcher.Invoke(() =>
        {
            //code to update ui
            this.Label.Content = string.Format("Fired at {0}", DateTime.Now);
        });
    }
}

edited Feb 20 '15 at 06:16

answered Feb 20 '15 at 05:42

Dima Korn

546
3
5

@dbvega:Am used ur code ,that also hangs tha application for several seconds – NvadeepKumar Feb 20 '15 at 06:06
@DimaKorn how to code to update ui?am using WPF textbox – NvadeepKumar Feb 20 '15 at 06:50
@NvadeepKumar, just put all code, manipulating you UI controls, into delegate, passed to Dispatcher.Invoke. For WPF textbox something like `TextBox.Text="any message you want to show to user"` – Dima Korn Feb 20 '15 at 06:56
@DimaKorn:no messgaebox needed because its continously checking every 30seconds, without affect UI – NvadeepKumar Feb 20 '15 at 07:03

denys-vega · Answer 2 · 2015-02-20T06:32:47.920

2

var timer = new System.Threading.Timer(
    delegate
    {
        //--update functions here (large operations)
        var value = Environment.TickCount;

        //--run update using interface thread(UI Thread)

        //--for WinForms
        Invoke(
            new Action(() =>
            {
                //--set the value to UI Element
            }));

        //--for WPF
        Dispatcher.Invoke(
            new Action(() =>
            {
                //--set the value to UI Element
            }), null);
    });
var period = TimeSpan.FromSeconds(30);
timer.Change(period, period);

I hope it helps.

edited Feb 20 '15 at 06:32

answered Feb 20 '15 at 05:58

denys-vega

3,522
1
19
24

:Am used ur code ,that also hangs tha application for several seconds – NvadeepKumar Feb 20 '15 at 06:11
@NvadeepKumar System.Threading.Timer is served by thread pool threads. Please, check my answer again. – denys-vega Feb 20 '15 at 06:25
@dvega set value to UI means? – NvadeepKumar Feb 20 '15 at 06:43
@dvega: How sir,i dont know? – NvadeepKumar Feb 20 '15 at 06:47
@NvadeepKumar Seriously? If you're using a WPF TextBox control named TextBox1 sets the Text: `TextBox1.Text = valueCalculated;` – denys-vega Feb 20 '15 at 07:23

Ajay · Answer 3 · 2015-02-20T07:13:18.700

0

This is worked for me

 public Form1()
    {
        InitializeComponent();

        var timer = new System.Timers.Timer(500);
        // Hook up the Elapsed event for the timer.
        timer.Elapsed += timer_Elapsed;
        timer.Enabled = true;
    }

    void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {
        Invoke(
          new Action(() =>
          {
              label1.Text += "Test Label";
              Application.DoEvents();
          }));
    }

edited Feb 20 '15 at 07:13

answered Feb 20 '15 at 05:42

Ajay

444
2
9

Is given before the function call? – NvadeepKumar Feb 20 '15 at 05:49
:Is application or other process hang while using application? – NvadeepKumar Feb 20 '15 at 07:15
am worked with your code,but still 10seconds hangs the application – NvadeepKumar Feb 20 '15 at 07:21
No I have tested it is not hanging my form. Can you post your code so I can test according to your scenario ? – Ajay Feb 20 '15 at 07:32

How to check every 30seconds with dispatchertimer without affect the UI in c#?

3 Answers3