Noorul
0
How to intercept app_closing or app_entering_background in WinUi 3 app.
In UWP apps we do have Application_EnteredBackground event , in which we can intercept app close, we use GetDeferral() to save data .
Is there any same kind of event in WinUI 3 apps, I need to save data on app close, or entering background.
Tried window_VisibilityChanged and window_Closed events, but not able to use GetDeferral().
Kindly help
Thanks in advance .
Noorul
Here is my test code for your reference, you can intercept the closing event.
(closing is executed before closed)
public sealed partial class MainWindow : Window
{
private AppWindow _appWindow;
public MainWindow()
{
this.InitializeComponent();
this.Closed += OnClosed;
_appWindow = GetAppWindowForCurrentWindow();
_appWindow.Closing += OnClosing;
}
private void OnClosed(object sender, WindowEventArgs e)
{
string btnText = myButton.Content.ToString();
}
private async void OnClosing(object sender, AppWindowClosingEventArgs e)
{
string btnText = myButton.Content.ToString();
e.Cancel = true; //Cancel close
//Otherwise, the program will not wait for the task to execute, and the main thread will close immediately
//await System.Threading.Tasks.Task.Delay(5000); //wait for 5 seconds (= 5000ms)
Func<bool> funcSaveData = () =>
{
//perform operations to save data here
return true;
};
var funResult = await Task.Run(funcSaveData);
this.Close(); //close
}
private AppWindow GetAppWindowForCurrentWindow()
{
IntPtr hWnd = WindowNative.GetWindowHandle(this);
WindowId myWndId = Win32Interop.GetWindowIdFromWindow(hWnd);
return AppWindow.GetFromWindowId(myWndId);
}
private void myButton_Click(object sender, RoutedEventArgs e)
{
myButton.Content = "Clicked";
}
}