Dispatch timer won't work

Question

I'm trying to figure out how a dispatch timer works so I can implement it into my program, I followed the exact instructions on a website and looked for answers on stack overflow. People said their problem was fixed but I have very similar code and it wont work...

The error is:

No overload for "timer_Tick" matches delegate "EventHandler<object>"

What can i do?

public MainPage()
{
    this.InitializeComponent();

    DispatcherTimer timer = new DispatcherTimer();
    timer.Interval = TimeSpan.FromSeconds(1);
    timer.Tick += timer_Tick;
    timer.Start();
}

void timer_Tick(EventArgs e)
{
    TimeRefresh();
}

score 5 · Accepted Answer · edited May 23 '17 at 11:52

5

You need to fix the event handler signature. It's missing the sender and the type of the second parameter is just object. (See the documentation.)

void timer_Tick(object sender, object e)
{
    TimeRefresh();
}

You also need to add a using Windows.UI.Xaml; to the top of your class, or instantiate the timer using the full namespace:

Windows.UI.Xaml.DispatcherTimer timer = new Windows.UI.Xaml.DispatcherTimer();

If anyone stumbles on this and is using WPF, it has it own DispatchTimer. Make sure you're referencing "WindowsBase" (should be there by default). The signature is slightly different.

void timer_Tick(object sender, EventArgs e)
{
    TimeRefresh();
}

The namespace it lives in is different too. Either add using System.Windows.Threading; to the top, or qualify with the full namespace:

System.Windows.Threading.DispatcherTimer timer
    = new System.Windows.Threading.DispatcherTimer();

If you're using WinForms, you want to use a different timer. Read this for the difference between the WinForms Timer and the WPF DispatchTimer.

edited May 23 '17 at 11:52

Community

1
1

answered Dec 18 '15 at 03:09

Grant Winney

65,241
13
115
165

I use DispatchTimer, But when i use `System.Windows.Threading.DispatcherTimer` It says `The type or namespace name 'Threading' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)` – mateos Dec 18 '15 at 03:13
Must be missing `System.Windows.Threading` assembly reference – Victor Dec 18 '15 at 03:16
@Victor , How do I add that? – mateos Dec 18 '15 at 03:17
Maybe I am missing "WindowsBase.dll" I haven't added a reference before, How can try see if its missing and add it if it is? – mateos Dec 18 '15 at 03:18
No, All i see is system.windows – mateos Dec 18 '15 at 03:28
what about including `timer.Tick += new EventHandler(timer_Tick);` line – sujith karivelil Dec 18 '15 at 03:46
No, Its definitely a WPF application. I know the difference between WinForms and WPF @un-lucky – mateos Dec 18 '15 at 03:48
Do I right click on references and click add reference? I tried searching for windowsbase but nothing came up – mateos Dec 18 '15 at 03:53
"No framework assemblies were found on this machine" – mateos Dec 18 '15 at 04:01

score 3 · Answer 2 · edited May 23 '17 at 12:30

3

You have to specify the source of event.

void timer_Tick(object sender,EventArgs e)
{
    TimeRefresh();
}

And the event registration should be like the following:

timer.Tick += new EventHandler(timer_Tick);

Here you can read more about events and event handlers

edited May 23 '17 at 12:30

Community

1
1

answered Dec 18 '15 at 03:10

sujith karivelil

28,671
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55
88

Dispatch timer won't work

2 Answers2

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