private async Task PreventFromSuspending()
{
ExtendedExecutionForegroundSession newSession = new ExtendedExecutionForegroundSession();
newSession.Reason = ExtendedExecutionForegroundReason.Unconstrained;
newSession.Revoked += SessionRevoked;
ExtendedExecutionForegroundResult result = await newSession.RequestExtensionAsync();
switch (result)
{
case ExtendedExecutionForegroundResult.Allowed:
_session = newSession;
break;
default:
case ExtendedExecutionForegroundResult.Denied:
newSession.Dispose();
break;
}
}
private async void ExtendedExecutionRequestAsync()
{
var newSession = new ExtendedExecutionForegroundSession();
newSession.Reason = ExtendedExecutionForegroundReason.Unconstrained;
newSession.Description = "Long Running Processing";
//newSession.Revoked += SessionRevoked;
ExtendedExecutionForegroundResult result = await newSession.RequestExtensionAsync();
switch (result)
{
case ExtendedExecutionForegroundResult.Allowed:
break;
default:
case ExtendedExecutionForegroundResult.Denied:
break;
}
}
/// <summary>
/// Initialize or clean up the camera and our UI,
/// depending on the page state.
/// </summary>
/// <returns></returns>
private async Task SetUpBasedOnStateAsync()
{
Debug.WriteLine("Entering SetupBasedOnStateAsync(): " + new System.Diagnostics.StackTrace().ToString());
// Avoid reentrancy: Wait until nobody else is in this function.
while (!_setupTask.IsCompleted)
{
await _setupTask;
}
// We want our UI to be active if
// * We are the current active page.
// * The window is visible.
// * The app is not suspending.
bool show = _isActivePage && Window.Current.Visible && !_isSuspending;
if (_previewVideoEnabled != show)
{
_previewVideoEnabled = show;
PreviewToggleSwitch.IsOn = show;
}
Func <Task> setupAsync = async() =>
{
//if(!show)
if (_isSuspending)
{
Debug.WriteLine("SetupBasedOnStateAsync - shutting down!");
_setupBasedOnState = false;
await ShutdownAsync();
await StopServer();
}
else if (!_setupBasedOnState)
{
Debug.WriteLine("SetupBasedOnStateAsync - setting up!");
_setupBasedOnState = true;
ExtendedExecutionForegroundSession newSession = new ExtendedExecutionForegroundSession();
newSession.Reason = ExtendedExecutionForegroundReason.Unconstrained;
newSession.Description = "Long Running Processing";
newSession.Revoked += SessionRevoked;
ExtendedExecutionForegroundResult result = await newSession.RequestExtensionAsync();
switch (result)
{
case ExtendedExecutionForegroundResult.Allowed:
Debug.WriteLine("Extended Execution in Foreground ALLOWED.");
_extendedExecutionSession = newSession;
break;
default:
case ExtendedExecutionForegroundResult.Denied:
Debug.WriteLine("Extended Execution in Foreground DENIED.");
break;
}
await MJPEGStreamerInitAsync();
await InitializeCameraAsync();
await StartServer();
// Prevent the device from sleeping while running
_displayRequest.RequestActive();
}
};
Debug.WriteLine("SetupBasedOnStateAsync -calling setup Async!");
_setupTask = setupAsync();
Debug.WriteLine("SetupBasedOnStateAsync -setup Async called!");
await _setupTask;
Debug.WriteLine("SetupBasedOnStateAsync - awaited setup task!");
UpdateCaptureControls();
}
