In WinRT the Suspended event is supposed to be used to save application data. It is even written in the templates that come with Visual Studio. However when the user closes the app the Suspended event does not fire until 10 seconds later. If the user starts the application in the meantime the data is lost. How should I proceed in this case? I tried other events like page's NavigatedFrom but none of them fired.
You could try this:
Window.Current.Activated += (sender, args) =>
{
if (args.WindowActivationState ==
CoreWindowActivationState.Deactivated)
; //save data
};
If an user close the App he expects the App start from scratch next time. But if user left the App to do another things he expects to return back to the last action.
If you force your app to save state even when user close the app:
How could the user start the app from scratch in any time he wants?
Related
I have a Line-of-Business (LoB) Windows 8.1 Store application I developed for a client. The client side-loads it on several Windows 10 tablets. They use it in an environment where WiFi is spotty at best and they would like to get some sort of notification inside the app, regardless of what page they are on, notification that will let them know that they've lost connectivity to the network. I have created a method on my Web API that is not hitting the repository (database). Instead, it quickly returns some static information regarding my Web API, such as version, date and time of the invocation and some trademark stuff that I'm required to return. I thought of calling this method at precise intervals of time and when there's no response, assume that the Web API connectivity is lost. In my main page, the first one displayed when the application is started, I have the following stuff in the constructor of my view model:
_webApiStatusTimer = new DispatcherTimer();
_webApiStatusTimer.Tick += OnCheckWebApiStatusEvent;
_webApiStatusTimer.Interval = new TimeSpan(0, 0, 30);
_webApiStatusTimer.Start();
Then, the event handler is implemented like this:
private async void OnCheckWebApiStatusEvent(object sender, object e)
{
// stop the timer
_webApiStatusTimer.Stop();
// refresh the search
var webApiInfo = await _webApiClient.GetWebApiInfo();
// add all returned records in the list
if (webApiInfo == null)
{
var messageDialog = new MessageDialog(#"The application has lost connection with the back-end Web API!");
await messageDialog.ShowAsync();
// restart the timer
_webApiStatusTimer.Start();
}
}
When the Web API connection is lost, I get a nice popup message that informs me that the Web API is no longer available. The problem I have is that after a while, especially if I navigate away from the first page but not necessary, I get an UnauthorizedAccessException in my application.
I use the DispatcherTimer since my understanding is that this is compatible with
UI threads, but obviously, I still do something wrong. Anyone cares to set me on the right path?
Also, if you did something similar and found a much better approach, I'd love to hear about your solution.
Thanks in advance,
Eddie
First, If you are using Windows Store Apps, then you could possibly use a Background task to check poll for the status of the web api instead of putting this responsibility on your view model, its not the viewmodels concern
Second, if you are connecting from your Windows store app to your API then one successful authentication/ authorization for the first time, how and where do you store the token (assuming you are using token authentication). If you are (and ideally you should), is there a timer that you start which is set to the token expiration time? Is your local storage getting flushed somehow and loosing the aurthorization data?
Need more information.
I have a ViewController that will request access to location services on init via
if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined)
{
[_locationManager requestWhenInUseAuthorization];
}
This triggers the "Allow app to access your location while you use the app?"-alert.
I use [self addUIInterruptionMonitorWithDescription:handler:] to react to this. I am encountering the following problem: after dismissing the request-dialog, the ui-test does not continue. The alert is dismissed, but Xcode waits for the app to become idle, but it looks like the app is idle:
t = 67.35s Wait for app to idle
The test fails, because the app is stuck here. If i tap into the simulator, Xcode logs.
t = 72.27s Synthesize event
and continues the test.
Is there a reason, why Xcode tries to wait for the app? A workaround seems to be to tell Xcode that the UI changed or an event happened. Is there a way to trigger this?
After presenting the alert you must interact with the interface. This is a known bug with Xcode 7.2. Simply tapping the app works just fine, but is required.
addUIInterruptionMonitorWithDescription("Location Dialog") { (alert) -> Bool in
alert.buttons["Allow"].tap()
return true
}
app.buttons["Find Games Nearby?"].tap()
app.tap() // need to interact with the app for the handler to fire
XCTAssert(app.staticTexts["Authorized"].exists)
See my blog post for more information.
I have a UI test which involves the dismissal of a system-generated UIAlertController. This alert asks the user for the permission to access the device's calendar. The objective of the test is the behaviour after a tap on the OK button:
1 let app = XCUIApplication()
...
// this code was basically generated by the recording feature of XCode 7
2 app.alerts.elementBoundByIndex(0).collectionViews.buttons["OK"].tap()
Now, instead of clicking the OK button, line 2 makes the simulator tap onto the first button which happens to be the Cancel button...
Additionally, I found out that the testing framework does not accurately recognize the appearing alert. So if I check the current count of alerts I always get 0:
// ...tap...
let count = app.alerts.count // == 0
This also happens if I use an NSPredicate for the condition and wait for several seconds.
Is it possible that UI tests do not work reliably with system-generated alerts? I am using XCode 7.0.1.
Xcode 7.1 has finally fixed the issue with system alerts. There are, however, two small gotchas.
First, you need to set up a "UI Interuption Handler" before presenting the alert. This is our way of telling the framework how to handle an alert when it appears.
Second, after presenting the alert you must interact with the interface. Simply tapping the app works just fine, but is required.
addUIInterruptionMonitorWithDescription("Location Dialog") { (alert) -> Bool in
alert.buttons["Allow"].tap()
return true
}
app.buttons["Request Location"].tap()
app.tap() // need to interact with the app for the handler to fire
The "Location Dialog" is just a string to help the developer identify which handler was accessed, it is not specific to the type of alert. I believe that returning true from the handler marks it as "complete", which means it won't be called again.
I managed to dismiss access prompt for contacts like this:
let alert = app.alerts["\u{201c}******\u{201d} Would Like to Access Your Contacts"].collectionViews.buttons["OK"]
if alert.exists
{
alert.tap()
}
Replace asterisks with your app's name. It might work the same for calendar.
This is what I ended up using to get the prompt to appear and then allow access to Contacts:
func allowAccessToContacts(textFieldsName: String)
{
let app = XCUIApplication()
let textField = app.textFields[textFieldsName]
textField.tap()
textField.typeText("aaa")
let alert = app.alerts["\u{201c}******\u{201d} Would Like to Access Your Contacts"].collectionViews.buttons["OK"]
if alert.exists
{
alert.tap()
}
textField.typeText("\u{8}\u{8}\u{8}")
}
I'm developing a class library for windows 10 universal apps (mobile and desktop device families only). I need to invoke an event if the user has been idle(no touch, mouse move, key press etc) for x number of seconds. This method can be used to solves this problem on android. But I couldn't find a solution on windows UWP.
Is there an API available in UWP to achieve this?
You can detect global input with various events on the app's CoreWindow:
Touch and mouse input with CoreWindow.PointerPressed, PointerMoved, and PointerReleased.
Keyboard input: KeyUp and KeyDown (the soft keys) and CharacterReceived (for characters generated via chords & text suggestions)
Use these to detect the user is active and idle out if it goes too long without any of these events.
I know this is really old question, but I think you can now get to same result with RegisterBackgroundTask
Just set:
new TimeTrigger(15, false) //For time trigger
Link
new SystemCondition(SystemConditionType.UserNotPresent)) //And so you want to know so user is not present
Link
Example usage in App.xaml.cs:
var builder = new BackgroundTaskBuilder();
builder.Name = "Is user Idle";
builder.SetTrigger(new TimeTrigger(2, false)); //two mins
builder.AddCondition(new SystemCondition(SystemConditionType.UserNotPresent));
// Do not set builder.TaskEntryPoint for in-process background tasks
// Here we register the task and work will start based on the time trigger.
BackgroundTaskRegistration task = builder.Register();
task.Completed += (sender, args) =>
{
//Handle user not present (Idle) here.
};
I am quite new to windows 8 phone and I don't know all the life cycle methods and when what is called.
My problem is the following: I have a page that loads some data from the disk and when the user exits the program ( or suspends ) the data should be saved. As far as I can tell Page doesn't have an OnSuspending method only someOnNavigatingFrom, but those are not called when you just exit the program. So I read that I should use the OnSuspending in my App.xaml.cs, but this class doesn't have this data and also shouldn't have it, maybe only for OnSuspending. But I don't know how to get the data from my page in the OnSuspending method.
The OnSuspending event is quite fragile and you cannot expect it to run and save the state for a long time. But it depends on how long it would take for you to save. It doesn't even get triggered when you hit the home key while closing the app. If you really want an easy way. Just register a background task. While your app is in the background, the state can be saved and when you open the app again things are in place.
There are certain constraints With Background task as well, you cant do heavy lifting etc...here's a link you could use.
https://msdn.microsoft.com/en-us/library/windows/apps/xaml/hh977056.aspx
Implement an observer pattern (i.e. pub/sub) for your view-models to subscribe to in the event that your app is being suspended.
Your app handles the suspended event. As a result, publish a message for your view-models to respond to within your app's method handler for the suspended event.
You can use an EventAggregator or MessageBus (that I wrote).