I want to exit my app when the user press back button. I have used Hardware Pressed events to navigate between pages.
When I navigated to the first page where no Hardware Button press event is used and press back button it goes back to the Menu Screen and not getting terminated as shown in image
Need help.
I also faced the same problem but by using the following piece of code
Application.Current.Exit()
the application shuts down properly.
This is generally not recommended. Think hard about why you want to do this and if it really makes sense. Barring recovering from a failure it usually doesn't. The expected behavior is for the app to work nicely with the process lifetime code. There is typically no downside to keeping the app suspended, and it is much more efficient to resume from suspension than to restart completely. The user can use the built-in options to explicitly close the app if desired.
That said, you can call Windows.UI.Xaml.Application.Exit .
You can use this snippet to make the back button react the same as WP8 on WP8.1. In public App():
#if WINDOWS_PHONE_APP
HardwareButtons.BackPressed += HardwareButtons_BackPressed;
#endif
and in the same scope as App():
#if WINDOWS_PHONE_APP
void HardwareButtons_BackPressed(object sender, BackPressedEventArgs e)
{
Frame rootFrame = Window.Current.Content as Frame;
if (rootFrame != null && rootFrame.CanGoBack)
{
e.Handled = true;
rootFrame.GoBack();
}
}
#endif
Related
So I have an app that on a button press: starts a timer, cycles through one (++) piece of data and hides the start button and instead shows a stop and next button.
I have looked into messaging center and I thought it was fixing the problem (here's the link Xamarin.Forms how do I access a public function from another CS file?) but it didn't fix the problem completely.
If the app has the timer running (aka you hit the start button) and then interrupt the process by hitting the home button on your phone, the app works fine and the app hides the stop/next buttons and shows the start button and stops the timer. If you haven't started the process at all (aka you haven't hit the start button) and you hit the home button on your phone the app throws an exception error because what I'm changing with messaging center "doesn't need changing because it never changed". Is there a better way to handle this situation?
Can I use if/else statements in app state with messagingcenter?? I'm stuck.
App.xaml.cs
protected override void OnSleep()
{
// Handle when your app sleeps
Debug.WriteLine("~~~~~~~~~~~~~~OnSleep~~~~~~~~~~~~~");
MessagingCenter.Send<App>(this, "OnSleep");
}
MainPage.xaml.cs
MessagingCenter.Subscribe<App>(this, "OnSleep", (sender) => {
//shows start button instead of stop button
StartGrid.IsVisible = true;
//hides stop button
StopNextGrid.IsVisible = false;
//stops timer
timer.Stop();
timer = null;
//stops sound
startSound.Stop();
stopSound.Play();
});
Just can see the partial code,you should check if your timer is initialized before executing the method.
When you do not click the start button, you need to check whether the timer is initialized, in order to perform the following timer operation.
If no want to know whether timer is initialized. You can try this：
Modify in your notification handling method.If the state of your timer and button has not changed, you don't need to do anything in the notification.Here I use the timer as a judgment.
MessagingCenter.Subscribe<App>(this, "OnSleep", (sender) => {
//shows start button instead of stop button
if (null != timer)
{
StartGrid.IsVisible = true;
//hides stop button
StopNextGrid.IsVisible = false;
//stops timer
timer.Stop();
timer = null;
//stops sound
startSound.Stop();
stopSound.Play();
}
});
I've a very heavy application that takes some time to close itself (it also depends on the pc where it is running.. but this is not the matter right now)
I would like to show a custom window with a message during this closing time, but as soon as i call the "Shutdown" method every window disappears (except made for the MessageBox).
This is the code i'm trying to use to achieve my objective
void MainWindow_Closing(object sender, CancelEventArgs e)
{
Task.Factory.StartNew(() =>
{
var closingWaitTest = "application closing, please wait;
Application.Current.Dispatcher.Invoke(() =>
{
var closingSplash = new ClosingSplashWindow(closingWaitTest);
closingSplash.Show();
});
MessageBox.Show(closingWaitTest);
});
Application.Current.Shutdown();
}
I Added a messageBox just to check, and it actually works. I mean, the MessageBox stays open until the application process is alive (i check that from the windows TaskManager) while my Window is instantly closed.
Hope someone can give some advice about this,
thanks in advance (:
EDIT -
So, the main problem is that as soon as i call the Application.Current.Shutdown my splash window instantly closes, while the application process is still up and running for some time (disposing all my things before calling shutdown actually reduced this time a bit).
The point is that i would like to show a window for the entirety of time that the process is still up; given the fact that a MessageBox behaves exactly like that, my question is:
Is there a way to make my ClosingSplashWindow behave like a MessageBox and stay visible until the application process is really dead?
Since Application.Current.Shutdown(); is going to close the application immediately. Maybe you first have a flag to track that application is being closed, cancel the Closing event and initiate the Resource cleanup followed by Application.Current.Shutdown(); again.
The Application_Closing handler may get fired once again, since you've a flag which says you're about to close you can directly exit the handler and all should be good.
First of all, you want to have a flag which indicates that your application is currently shutting down:
private bool IsShuttingDown { get; set; }
Then you should cancel closing operation, perform some heavy work and shut down your application:
private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (!IsShuttingDown)
{
e.Cancel = true;
ShowSplashWindow();
PerformHeavyOperation();
Application.Current.Shutdown();
IsShuttingDown = true;
}
}
In the end I solved the problem creating another application that shows a window while the main application process is still up and running.
I know it is not the best way to do it, but i was not able to do it in any other way..
Thank for the support! :)
I'm developing an App for windows 8.1 and i need to execute a method to pause some tasks or play a sound when the app is minimized in the sidebar.
I tried:
Application.Current.Suspending += new SuspendingEventHandler(Method_Name);
private void Method_Name(object sender, object e)
{
Other_Method();
}
But this event takes a few seconds (5~10) to occur after I minimize the app.
What event occurs when the app is dragged to the sidebar? What process sends the event?
Thanks.
Check out this post for the answer. It's WindowSizeChanged and check the value of ApplicationView.Value.
[EDIT]
Apparently for 8.1 things have changed a bit. The ApplicationView stuff is deprecated (that was quick) but this still takes place in SizeChanged for the window. Check out this for more details.
After long searching I found something that is not exactly what i wanted, but it works.
This event occurs everytime that visibility of the page changes (Is started, is maximized or minimized for exemple), then you must do some conditions using the if operator.
Window.Current.VisibilityChanged += new WindowVisibilityChangedEventHandler(One_Method);
private void One_Method(object sender, Windows.UI.Core.VisibilityChangedEventArgs e)
{
if(Some_Condition)
{
//TODO: Code that you want execute.
}
}
I'll keep the answer in open for the case of someone knows something more efficient.
I have a C# GUI app that shows a message using MessageBox.Show(Message);, however if the user fails to click on this, and then requests shutting down the PC, it blocks the shutdown.
How do I prevent my open dialog box from blocking the shutdown?
I'm assuming you're using WinForms since you didn't mention WPF. You can't use a MessageBox if you want to control closing behavior. You'll have to build your own screen to act as a message box and use the ShowDialog method to display it. Your screen can handle the FormClosing event to detect when Windows is shutting down:
private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
{
if (e.CloseReason == CloseReason.WindowsShutDown)
{
//...
}
}
So you'll want to allow the screen to close in this case and perhaps take other action for other types of close signals. To prevent the screen from closing, set the Cancel flag on the FormClosingEventArgs parameter to true;
I'm experiencing odd behavior in the wp7 emulator.
I have a dead simple app that's mostly directly from the template generated by VS 2010.
From App.xaml:
<!--Required object that handles lifetime events for the application-->
<shell:PhoneApplicationService
Launching="Application_Launching" Closing="Application_Closing"
Activated="Application_Activated" Deactivated="Application_Deactivated"/>
Tombstoning code from App.xaml.cs:
private void LoadSettings()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
ICollection<TicTacSpot> getSpots;
if (settings.TryGetValue<ICollection<TicTacSpot>>("spots", out getSpots))
{
Spots = getSpots;
}
if (Spots == null)
{
Spots = new List<TicTacSpot>();
}
}
private void SaveSettings()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
settings["spots"] = Spots;
}
// Code to execute when the application is launching (eg, from Start)
// This code will not execute when the application is reactivated
private void Application_Launching(object sender, LaunchingEventArgs e)
{
LoadSettings();
}
// Code to execute when the application is activated (brought to foreground)
// This code will not execute when the application is first launched
private void Application_Activated(object sender, ActivatedEventArgs e)
{
LoadSettings();
}
// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
SaveSettings();
}
// Code to execute when the application is closing (eg, user hit Back)
// This code will not execute when the application is deactivated
private void Application_Closing(object sender, ClosingEventArgs e)
{
SaveSettings();
}
Seems straightforward enough. I set breakpoints in all these methods. When I hit F5 to deploy the app, the event handlers that are hit are:
Application_Launching()
Application_Deactivated()
Oddly, these are hit, even though the emulator doesn't show the app opening or closing.
In the emulator, I then open the app, play around, close it, then re-open it. I use both the "back" and "start" buttons to close it. Despite this, I am unable to get any event handlers to be hit again.
What am I doing wrong here?
Is the debug session is still active?
I have found that if you set breakpoints that get hit on start-up and you do not continue with a certain amount of time (e.g. < 10 seconds) your debug session will be disconnected.as the OS terminates the application.
Like Dennis said, to debug the Activated event handler you need to launch a new debug session just after pressing the back button. The sequence would be :
launch debug
play with the app, hit Start
quit application, debug session stopped
hit back button - black screen on the emulator
launch debug session , be quick :) after 10 sec, OS terminates the application