我如何单击UWP上的“退出”按钮？

Question

I want to delete my img what i made, when my program is ended.

(It means when user click the exit button.)

Click this button.

Or, when user click the exit button, then I want to show the popup window.

So User can save their img before the program is ended.

But I couldn't find that way.

Is this impossible way?

Please tell me anything!! Thanks for reading this.

Answer 1

Take a look at application lifecycle article . You shouldn't add blocking code to the app suspended event. You need to silently save its state and restore state once your app gets back to active state as if it was not closed at all.

Regarding close button from ms docs :

There is not an event to indicate that the user closed the app. When an app is closed by the user, it is first suspended to give you an opportunity to save its state. In Windows 8.1 and later, after an app has been closed by the user, the app is removed from the screen and switch list but not explicitly terminated.

Closed-by-user behavior: If your app needs to do something different when it is closed by the user than when it is closed by Windows, you can use the activation event handler to determine whether the app was terminated by the user or by Windows. See the descriptions of ClosedByUser and Terminated states in the reference for the ApplicationExecutionState enumeration.

Answer 2

See the accepted answer of this question.

And to understand more how you can incorporte this in your application you can also refer to this blog post .

Basically you need 2 aspects to achieve this:

1. confirmAppClose restricted capability.
2. an event to handle the app closing. SystemNavigationManagerPreview.GetForCurrentView().CloseRequested