Why would my event handler not get called?

Question

I've got this xaml:

<Button VerticalAlignment="Bottom"
        Click="SaveAndGoBack"
        IsEnabled="{Binding Frame.CanGoBack,
                            ElementName=pageRoot}"
        Style="{StaticResource BackButtonStyle}" />

...but on "tapping" (clicking) the back button, while it does return to the previous page, SaveAndGoBack() is not called - I have a breakpoint on the first line, and it is not reached.

The button is obviously enabled, because I am able to select it and "go back." So why would the event handler not be reached?

UPDATE

Changing clicked to tapped makes no difference. This is the XAML now:

<Button VerticalAlignment="Bottom"
        Tapped="SaveAndGoBack"
        IsEnabled="{Binding Frame.CanGoBack,
                            ElementName=pageRoot}"
        Style="{StaticResource BackButtonStyle}" />

...and this is the method, with a breakpoint on the first line, which is never reached (but the Main Page is returned to):

private async void SaveAndGoBack(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs args)
{
    SOs_Locations sos_locs = new SOs_Locations { GroupName = txtbxGroup.Text };
    int locNum;
    int.TryParse(txtbxLocationNum.Text, out locNum);
    sos_locs.LocationTitle = txtbxTitle.Text;
    sos_locs.CivicAddress = txtbxAddress.Text;
    double lat;
    double.TryParse(txtbxLatitude.Text, out lat);
    sos_locs.Latitude = lat;
    double lng;
    double.TryParse(txtbxLongitude.Text, out lng);
    sos_locs.Longitude = lng;
    if (cmbxDisplayColor.SelectedValue != null)
        sos_locs.LocationColor = cmbxDisplayColor.SelectedValue.ToString();
    await SQLiteUtils.UpdateLocationAsync(sos_locs);
    Frame.Navigate(typeof(MainPage));
}

scartag · Answer 1 · 2013-01-22T21:50:21.273

4

Click is a different event from a Tap. you should look for an event called Tapped and create an OnTapped handler for it.

My guess is that for your issue. The event isn't bubbling because in the LayoutAwarePage.cs the event is set to handled.

You can modify this page to suit your needs. Look for the CoreWindow_PointerPressed method and look for the area where it sets args.Handled = true

edited Jan 22 '13 at 21:50

answered Jan 22 '13 at 20:54

scartag

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How does this explain the fact that his application returns to the previous page? – ChrisF Jan 22 '13 at 21:00
@ChrisF if that is the default back button, that is it's behaviour. It has nothing to do with his code. Note that he says his method isn't called. – scartag Jan 22 '13 at 21:01
I saw that which also led me to believe that there's a different button involved here as well. In that case surely adding a `Tapped` event handler won't help (or am I missing something) – ChrisF Jan 22 '13 at 21:03
@ChrisF He wants to run some code before going back. The tapped event will help if he is sending a tap gesture. – scartag Jan 22 '13 at 21:04
Changing it to Tapped makes no difference; more specifics added above. – B. Clay Shannon-B. Crow Raven Jan 22 '13 at 21:40
@ClayShannon If you are using the default templates. Check your LayoutAware page. Look for the GoBack method and run whatever code you need to run there. – scartag Jan 22 '13 at 21:45
@Scartag: I started with a Basic Page and have no LayoutAwarePage, CoreWindow_PointerPressed, or args.Handled = true in my project. – B. Clay Shannon-B. Crow Raven Jan 23 '13 at 22:50
@ClayShannon please check the common folder in your solution, from what i know as soon as you add a Page that includes a grid, this is automatically added for you. – scartag Jan 23 '13 at 22:55
The Common folder has StandardStyles.xaml only. – B. Clay Shannon-B. Crow Raven Jan 24 '13 at 01:48

score 1 · Answer 2 · edited May 23 '17 at 12:12

1

Use the Tapped event instead as it handles click, tap and stylus events whereas Click deals specifically with the mouse (see this answer for more details).

Here's some information on how they've tried to unify the events around the different pointing input modalities around touch.

edited May 23 '17 at 12:12

Community

1
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answered Jan 22 '13 at 21:09

mlorbetske

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Why would my event handler not get called?

UPDATE

2 Answers2