Show MessageDialog from app.xaml.cs in Windows Store app

Question

Im trying to show a message to the user when connection to the internet is lost

I have this method on my App.xaml.cs

static async void NetworkInformation_NetworkStatusChanged(object sender)
    {

        //Get the Internet connection profile
        //ConnectionProfile connectionProfileInfo = null;
        try
        {
            ConnectionProfile InternetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();

            if (InternetConnectionProfile == null)
            {
                ApplicationData.Current.LocalSettings.Values["INTERNET"] = false;

                ShowBox("Internet Lost");

                Frame rootFrame = Window.Current.Content as Frame;
                rootFrame.Navigate(typeof(LoginPage));
            }
            else
            {
                ApplicationData.Current.LocalSettings.Values["INTERNET"] = true;
            }
        }
        catch (Exception ex)
        {
            Debug.WriteLine("Unexpected exception occurred: " + ex.ToString());
        }

    }

and this other one

public async static void ShowBox(string msg)
    {
        try
        {

            await new MessageDialog(msg, "No Internet").ShowAsync();
        }
        catch (Exception e)
        {
            Debug.WriteLine(e.Message);
        }
    }

When i cause a connection lost ( disable my internet connection ) the ShowBox method gets called, and i get this exception on it:

Invalid window handle.

This API must be called from a thread with a CoreWindow or a window must have been set explicitly.

Is there any way to show a MessageDialog from that event?

Sounds like its expecting you to do this in the UI thread. Did you try this: http://stackoverflow.com/a/17315187/1565402 — lbrahim, Oct 29 '15 at 12:39
Possible duplicate of [Run code on UI thread in WinRT](http://stackoverflow.com/questions/10579027/run-code-on-ui-thread-in-winrt) — Matt Lacey, Oct 29 '15 at 17:57

score 3 · Answer 1 · edited Oct 05 '16 at 14:58

3

Try to add this:

CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() =>
{
    MessageDialog msg= new MessageDialog("No Internet");
    msg.ShowAsync();
 });

edited Oct 05 '16 at 14:58

Draken

3,134
13
34
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answered Oct 05 '16 at 14:20

Manuel Patrone

86
7

score 2 · Answer 2 · answered Nov 01 '18 at 22:33

Manuel Patrone answer is almost correct. just small fix for his answer.

await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
async() =>
{
    MessageDialog msg= new MessageDialog("No Internet");
    await msg.ShowAsync();
 });

score 0 · Answer 3 · edited Jul 22 '18 at 18:04

0

If you're running through the Desktop Bridge ensure that you're initializing your store context properly. See Using the StoreContext class with the Desktop Bridge for more information about it.

edited Jul 22 '18 at 18:04

Bhargav Rao

50,140
28
121
140

answered Jul 21 '18 at 19:58

Proteux

213
2
3

Show MessageDialog from app.xaml.cs in Windows Store app

3 Answers3