try
{
int c = 0;
int a = 5 / c;
}
catch (Exception ex)
{
}
Need to write Handled Exceptions globally in one place and without calling the errorlog method in each and every catch block in xamarin.forms and expect to get details in mainactivity for android and appdelegate for ios or any comman place in xamarin.forms
In your case you could use App Center . App Center Crashes will automatically generate a crash log every time your app crashes. The log is first written to the device's storage and when the user starts the app again, the crash report will be sent to App Center. Collecting crashes works for both beta and live apps, i.e. those submitted to the App Store. Crash logs contain valuable information for you to help fix the crash.
App Center Crashes provides you with an API to generate a test crash for easy testing of the SDK. This API checks for debug vs release configurations. So you can only use it when debugging as it won't work for release apps.
Crashes.GenerateTestCrash();
If your app crashed previously, you can get details about the last crash.
ErrorReport crashReport = await Crashes.GetLastSessionCrashReportAsync();
Set this callback if you want to decide if a particular crash needs to be processed or not. For example, there could be a system level crash that you'd want to ignore and that you don't want to send to App Center.
Crashes.ShouldProcessErrorReport = (ErrorReport report) =>
{
// Check the report in here and return true or false depending on the ErrorReport.
return true;
};
For more details about App Center you could check Get Started with Xamarin .
Related
I'm troubleshooting a location-based app launch cycle that works fine on iOS simulator, but apparently does not launch the app on an actual device.
I've set up UNNotifications for both enter and exit events. Both the simulator and the device(s) register and display these notifications.
The next thing that is supposed to happen is that the app goes through a launch process, setting the app's state in such a way that I can tell without being connected to the debugger whether the app has launched or not when I open it from the home screen.
On simulator, the didEnterRegion code gets called and I can step through the subsequent launch code using the debugger - success.
However when I take the device out (for a walk) all I get are UNNotifications, and no app launch (which I can tell from the UI in the app on the real device)
I'm sure I need to improve my testing strategy (welcome to suggestions!), but at this point I should be able to expect that the app should behave the same on the simulator and the actual device - it is not.
Why is the expected outcome happening on the simulator but not on the device?
LocationService.swift
func handleRegionEnterEvent (for region: CLRegion) {
ApplicationController.sharedInstance.didEnterRegion(region)
}
func handleRegionExitEvent (for region: CLRegion) {
ApplicationController.sharedInstance.didExitRegion(region)
}
ApplicationController.swift
func didEnterRegion (_ region: CLRegion) {
// Present Alert
delegate?.handleUNEvent(note: "ENTER: \(region.identifier)")
// Start launch cycle
}
AppDelegate.swift
extension AppDelegate: AppControllerDelegate {
func handleUNEvent(note: String?) {
// Show an alert if application is active
if UIApplication.shared.applicationState == .active {
guard let message = note else { return }
Alert().showAlert(withMessage: "Application received UN while active: \(message)", title: "UNNotification")
} else {
// Otherwise present a local notification
guard let body = note else { return }
let notificationContent = UNMutableNotificationContent()
notificationContent.body = body
notificationContent.sound = UNNotificationSound.default
notificationContent.badge = UIApplication.shared.applicationIconBadgeNumber + 1 as NSNumber
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
let request = UNNotificationRequest(identifier: "location_change",
content: notificationContent,
trigger: trigger)
UNUserNotificationCenter.current().add(request) { error in
if let error = error {
print("Error: \(error)")
}
}
}
}
}
The simulator sadly has a lot of differences from a device both in terms of data reported (you will not get speed for example) and also as you saw call flow may be different...
Something to check is to make sure you have the descriptions for the specific location permissions you are asking for in relation to location set up. For entering regions you probably want to make sure you have "always" access.
It may also be worth enabling wireless debugging, and walking around with laptop tethered to the device to verify with the debugger the didEnterRegion is truly not called, and there is a bug in the code that is supposed to display the UI you are expecting. At the very least perhaps you could get better logging as to the status of various location callbacks.
What happened: Code that executed on simulator was indeed crashing on the device and I was not reviewing crash logs from the device. This question arose from an issue that is neither ios, or core-location specific.
It has everything to do with choosing appropriate testing strategies and using all available information at one's disposal before coming to what may turn out to be premature conclusions.
However when I take the device out (for a walk) all I get are UNNotifications, and no app launch (which I can tell from the UI in the app on the real device)
I was mistaken to think that a) User Notifications that appear when the App is not running are presented by the system (as banners) and b) the App launches in another process. In fact my own code specifically executes the code that makes those notifications appear. Face-to-palm: Copying code from tutorials to achieve quick test results without even trying to understand what the code does can lead to that I suppose.
In Xcode, plug in your device and hit command-shift-2 to open Devices & Simulators window. Select your device on the left and hit "View Logs" button to bring up your crash log.
I have a finished application which I would like to make available to run on the iOS and Android platforms. I have tested the application as much as possible and it works without problem. But I know there is always the chance that something might go wrong and I could get an exception.
My question is how can I deal with this or what should I do. What happens on the phone, if a Forms application is deployed and there is an exception.
Would appreciate any advice or even links as to how this is handled.
If an exception is thrown and not handled by your code, the app will stop working (i.e. crash).
In order to handle these crashes we are using MS AppCenter (the successor to HockeyApp/Xamarin AppInsights).
You'll have to create a project there (one for each platform), and add the NuGet package to your projects. Afterwards you can initialize it with
AppCenter.Start("ios={Your App Secret};android={Your App Secret}",
typeof(Crashes)); // you'll get the app secrets from appcenter.ms
Crashes will be logged to AppCenter now and you'll be informed whenever there is a new crash.
Please note that it's best practice (if not required by law), that you ask the user for consent before sending the crash report (see here). You are using the delegate Crashes.ShouldAwaitUserConfirmation for that matter. You could for example show an action sheet with Acr.UserDialogs
private bool AwaitUserConfirmation()
{
// you should of course use your own strings
UserDialogs.Instance.ActionSheet(
new ActionSheetConfig
{
Title = "Oopsie",
Message = "The app crashed. Send crash to developers.",
Options = new List<ActionSheetOption>
{
new ActionSheetOption("Sure", () => Crashes.NotifyUserConfirmation(UserConfirmation.Send)),
new ActionSheetOption("Yepp, and don't bug be again.", () => Crashes.NotifyUserConfirmation(UserConfirmation.AlwaysSend)),
new ActionSheetOption("Nope", () => Crashes.NotifyUserConfirmation(UserConfirmation.DontSend))
}
});
return true;
}
I am using Visual Studio App Center for my Xamarin Forms Android Application for capturing the Analytics(Events and Crashes)
I am configuring crashes and analytics in OnStart of my App.Xaml.cs
AppCenter.Start($"android={Settings.Current.AppCenterAnalyticsAndroid};" +
typeof(Analytics), typeof(Crashes));
And for invoking the Events I am calling the below Method.
public void TrackEvent(string name, Dictionary<string, string> properties = null)
{
Analytics.SetEnabledAsync(true).ConfigureAwait(false);
Analytics.TrackEvent(name, properties);
}
Crashes are logging correctly in App Center But the events are not.
Also I can see the corresponding entries in Log Flow
Your app secret string is invalid because it contains + typeof(Analytics), it should be , typeof(Analytics).
Since you used the android key/value delimiter we could extract the appSecret and make it work with Crashes, but typeof(Analytics) ended up in the wrong appSecret parameter string.
You shouldn't need to add Analytics.SetEnabledAsync(true).ConfigureAwait(false);
Simply Call Analytics.TrackEvent(name, properties); (it doesn't need to be in a task anyways. I track my events in the Construtor of pages, for example.
Also, when you run the application, you get a debug Message confirming that AppCenter has been configured correctly, check if that is the case.
And, it may take a while, for them to appear in the Events.
Is there a way to prevent the app from crashing when JS uncaught errors occur?
Already tried to wrap app.start(...) inside try/catch, but it sure doesn't work:)
There is indeed, you can register an uncaughtErrorEvent listener.
Refer to the official documentation - https://docs.nativescript.org/core-concepts/application-lifecycle#use-application-events
You can drop the following in your app.js before bootstrapping the application
var application = require("application");
application.on(application.uncaughtErrorEvent, function (args) {
if (args.android) {
// For Android applications, args.android is an NativeScriptError.
console.log("NativeScriptError: " + args.android);
} else if (args.ios) {
// For iOS applications, args.ios is NativeScriptError.
console.log("NativeScriptError: " + args.ios);
}
});
There's no way to prevent the app from crashing. You can catch the error in the uncaughtError application event but the app will crash afterwards regardless.
Attempting to navigate to an error page won't work.
According to the comments on this GitHub issue:
Ability to specify custom error pages on uncaughtErrors · Issue #1718 · NativeScript/NativeScript
there is a way to customize the error page shown, but only on Android. Apparently there isn't anything similar available for iOS.
This is an older question but there is a documented way to prevent this using Nativescript older than 4.2 (you should be on 6+ now)
Disable rethrowing of uncaught js exceptions to native
Basically, catch the JS errors but do not crash the native app.
Note the disclaimer there as well. The script will be unstable at this point. Yes, it did not crash, but wherever it dies did not continue, so you might be worse off for stability. Putting the app in a bad state or just quitting/recrashing might be safer.
I am using the pro library.
But I just found doc for free library
I cannot find any doc for pro version.
Also, I don't know how to implement the background mode even using the pro sample.
Here are the steps:
Build the pro sample project
start the iBeacon source(using iPad) and it can be detected
start the application and then press home button the make it in
background
Turn off the iBeacon source
Turn on the iBeacon source
However, more than 5 minutes, the application does not launch
So, can anyone verify the step I did?
How can I test the background mode more easily?
Also, for the BootstrapNotifier, is it just work only first time when the device reboot?
After that, even I put application in background, the application will not launch when it detect iBeacon?
Your testing method sounds fine. I think the issue is that the reference app for the pro library only auto launches the app on the first detection after boot. After that, it sends a notification instead, and tapping on that notification launches the app.
This is purely for demonstration purposes. You can change it to auto launch on every detection if you wish. Simply alter the haveDetectedIBeaconsSinceBoot logic in this code:
#Override
public void didEnterRegion(Region arg0) {
// In this example, this class sends a notification to the user whenever an iBeacon
// matching a Region (defined above) are first seen.
Log.d(TAG, "did enter region.");
if (!haveDetectedIBeaconsSinceBoot) {
Log.d(TAG, "auto launching MainActivity");
// The very first time since boot that we detect an iBeacon, we launch the
// MainActivity
Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Important: make sure to add android:launchMode="singleInstance" in the manifest
// to keep multiple copies of this activity from getting created if the user has
// already manually launched the app.
this.startActivity(intent);
haveDetectedIBeaconsSinceBoot = true;
} else {
// If we have already seen iBeacons and launched the MainActivity before, we simply
// send a notification to the user on subsequent detections.
Log.d(TAG, "Sending notification.");
sendNotification();
}
}
The javadoc link was missing from the main documentation page when you posted this question. That is fixed now.