Мне было бы очень интересно увидеть более простое решение. Не допуская этого, вы можете создать арбитражный механизм. Что-то вдоль этих линий:
public class AppSynchronization
{
// Called by the main app on launch or on resume. It will signal the main app's intention to start.
// The main app will not perform any significant actions before this method returns.
public void ActivateMainApp() {...}
// Called by the main app. It will signal the fact that the main app is "going away".
public async Task MainAppSuspended() {...}
// Called by the background agent.
// It will signal the background agent intention to start.
// This method will only return if the main app is out of the way.
// It will return a cancellation token that will be used to cancel the activity of the background agent when the main app advertises its intention to start.
public async Task<CancellationToken> ActivateBackgroundAgent(CancellationToken cancelWait)
{
// Make sure the main app is not started or wait until the main app is out of the way
// Start a thread that is on the lookout for the main app announcing that it wants to start.
// When that happens it will cancel the cancellation token returned.
}
// <summary>
// Called by the background agent.
// It will signal the fact that the background agent completed its actions.
public async Task DeactivateBackgroundAgent()
}
В главном приложении:
private AppSynchronization appSynchronization;
public App()
{
...
this.appSynchronization = new AppSynchronization();
}
protected async override void OnLaunched(LaunchActivatedEventArgs e)
{
...
if (rootFrame.Content == null)
{
// Advertise the fact that the main app wants to start.
// The background agent will know to cancel whatever its doing.
// ActivateMainApp may have to be async although you need to make sure that OnLaunched supports that
this.appSynchronization.ActivateMainApp();
...
}
}
private async void OnResuming(object sender, object e)
{
...
// Advertise the fact that the main app wants to resume.
// The background agent will know to cancel whatever its doing.
this.appSynchronization.ActivateMainApp();
}
private async void OnSuspending(object sender, SuspendingEventArgs e)
{
var deferral = e.SuspendingOperation.GetDeferral();
...
// Advertise the fact that the main app is suspending.
// The background agent will know it is allowed to start doing work.
await _mainAppSynchronization.MainAppSuspended();
...
deferral.Complete();
}
private void OnUnhandledException(object sender, UnhandledExceptionEventArgs e)
{
...
// Advertise the fact that the main app is going away.
// The background agent will know it is allowed to start doing work.
_mainAppSynchronization.MainAppSuspended().Wait();
}
И в фоновом режиме агента:
public sealed class BackgroundTask : IBackgroundTask
{
public async void Run(IBackgroundTaskInstance taskInstance)
{
...
AppSynchronization appSynchronization = new AppSynchronization();
BackgroundTaskDeferral deferral = taskInstance.GetDeferral();
// Make sure that the main app is not started. If it is started then wait until the main app gets out of the way.
// It he main app is running this will wait indefinitely.
// Use backgroundAgentCancellationToken to cancel the actions of the background agent when the main app advertises its intention to start.
CancellationToken backgroundAgentCancellationToken = await appSynchronization.ActivateBackgroundAgent();
await DoBackgroundAgentWork(backgroundAgentCancellationToken)
// Advertise the fact that the background agent is out.
// DeactivateBackgroundAgent will make sure that the synchronization mechanism advertised the fact that the background agent is out.
// DeactivateBackgroundAgent may have to be declared async in case the synchronization mechanism uses async code to do what is needed.
await appSynchronization.DeactivateBackgroundAgent();
deferral.Complete();
}
Я не уверен, есть ли способ общения между процессами в UWP. Сам механизм арбитража может основываться на файлах на локальном хранилище.
Арбитражный механизм, возможно, должен включать механизм сердечного ритма в случае, если один или другой процесс аварийно завершится катастрофическим образом.
Вы нашли решение? Вы используете задачу запуска приложения? – peterincumbria