Develop Reference

How do I handle when user taps on local notification in Xamarin.Forms?

I am so frustrated with the Xamarin documentations. I am looking at doing one of the most basic thing, which is:
When a local notification comes out, a user taps the notification. It launches the App.
How do I handle this so that the app launches and acts according to the notification?
This is the official Xamarin Local Notifications documentation....
https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/local-notifications
In Stack Overflow or google searches I can't find any Solutions.
Nothing is mentioned on how to act on a tap to the notification

Ah yes, the docs can be improved! They just assume that you understand it, you should add a pull request or an issue to improve that page!
After you have created:
The INotificationManager interface in the Core project,
The iOS platform changes- iOSNotificationManager, iOSNotificationReceiver, AppDelegate changes
The Android platform changes- AndroidNotificationManager, MainActivity changes, if needed BroadcastReceiver
Then in the constructor of the page where you want to handle the changes, get the instance of the NotificationManager, and then subscribe to the NotificationReceived event which should get called when a user taps on the notification item.
public DashboardPage()
{
InitializeComponent();
notificationManager = DependencyService.Get<INotificationManager>();
notificationManager.NotificationReceived += (sender, eventArgs) =>
{
var evtData = (NotificationEventArgs)eventArgs;
Console.WriteLine("Title & Message: " + evtData.Title + evtData.Message);
};
}

You could try Plugin.LocalNotification too, it has a feature can hanle tap event, like:
public partial class App : Application
{
public App()
{
InitializeComponent();
// Local Notification tap event listener
NotificationCenter.Current.NotificationTapped += OnLocalNotificationTapped;
MainPage = new MainPage();
}
private void OnLocalNotificationTapped(NotificationEventArgs e)
{
// your code goes here
}
}
edit:
On iOS:
You can add code in DidRecieveNotiticationResponse(),like:
public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
{
if (response.IsDefaultAction)
{
ProcessNotification(response.Notification);
}
Console.WriteLine("Called");
App.Current.MainPage=new Page();
completionHandler();
}

Accessibility Event occurs only once after enabling the Accessibility Service

I've just started coding my app which uses Accessibility Service. I'll explain my problem in detail.
Below is my onServiceConnected method of MyAccessibilityService class
protected void onServiceConnected() {
super.onServiceConnected();
AccessibilityServiceInfo info = getServiceInfo();
info.eventTypes = AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED | AccessibilityEvent.WINDOWS_CHANGE_ADDED;
info.packageNames = new String[]
{THIRD_PARTY_APP_PACKAGE};
info.notificationTimeout = 100;
this.setServiceInfo(info);
}
The app is detecting events in onAccessibilityEvent() method
public void onAccessibilityEvent(AccessibilityEvent event) {
AccessibilityNodeInfo source = event.getSource();
if (source == null) {
return;
}
Toast.makeText(this, "Event Occured", Toast.LENGTH_SHORT).show();
}
Now when I open the third party app, I'm getting the Toast "Event occured". Now I close the app and when I open it again, the method is not called and I don't get any Toast. To make it working again, I have to disable the accessibility service of my app in my phone's Settings and again enable it.
I know I'm missing something and my only question is what should be the additional part of code or what modifications I need in order to detect the event every time I open the third party app?

Have you tried getting rid of the notification timeout? You probably don't need it, and it isn't the best-tested API.

getAccessibilityButtonController Android Accessibility Service

I have been looking at the new methods available for Accessibility in Android O. I ran across this new method called getAccessibilityButtonController, I am unsure precisely what it does and an intended use. I know that in Android O there is a navigation button that can be used for an accessibility service. Does this accessibility button only launch the accessibility service, or could it have other functionality within the service such as to do specific tasks? I am curious possible uses for the accessibility and the getAccessibilityButtonController methods. Thank you for your time.

It can do pretty much anything you want it to. From the android accessibility doc, the button allows you to register a callback that has an onClicked method. If you enable the button and provide said callback you can execute whatever you'd like in the context of that callback.
Edit: The android documentation has been updated so the following should no longer be necessary.
Note that if you read the doc there's currently an example that has a call to getAccessibilityButtonController() within onCreate(). This is incorrect because the controller isn't valid until onServiceConnected is called. I've modified the example below to show something that should work.
private AccessibilityButtonController mAccessibilityButtonController;
private AccessibilityButtonController
.AccessibilityButtonCallback mAccessibilityButtonCallback;
private boolean mIsAccessibilityButtonAvailable;
#Override
protected void onServiceConnected() {
mAccessibilityButtonController = getAccessibilityButtonController();
mIsAccessibilityButtonAvailable =
mAccessibilityButtonController.isAccessibilityButtonAvailable();
if (!mIsAccessibilityButtonAvailable) {
return;
}
AccessibilityServiceInfo serviceInfo = getServiceInfo();
serviceInfo.flags
|= AccessibilityServiceInfo.FLAG_REQUEST_ACCESSIBILITY_BUTTON;
setServiceInfo(serviceInfo);
mAccessibilityButtonCallback =
new AccessibilityButtonController.AccessibilityButtonCallback() {
#Override
public void onClicked(AccessibilityButtonController controller) {
Log.d("MY_APP_TAG", "Accessibility button pressed!");
// Add custom logic for a service to react to the
// accessibility button being pressed.
}
#Override
public void onAvailabilityChanged(
AccessibilityButtonController controller, boolean available) {
if (controller.equals(mAccessibilityButtonController)) {
mIsAccessibilityButtonAvailable = available;
}
}
};
if (mAccessibilityButtonCallback != null) {
mAccessibilityButtonController.registerAccessibilityButtonCallback(
mAccessibilityButtonCallback, null);
}
}

Force stop app using accessibility service Android?

I am using accessibility service for reading top package. But now I need to stop app and stop it's all running services through accessibility.
I have been searching on same found clean master doing same.
Please suggest how can I do same?

Using accessibility service you can force stop application.Ref below code
public class MyAccessibilityService extends AccessibilityService {
#Override
public void onAccessibilityEvent(AccessibilityEvent event) {
//TYPE_WINDOW_STATE_CHANGED == 32
if (AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED == event
.getEventType()) {
AccessibilityNodeInfo nodeInfo = event.getSource();
if (nodeInfo == null) {
return;
}
List<AccessibilityNodeInfo> list = nodeInfo
.findAccessibilityNodeInfosByViewId("com.android.settings:id/left_button");
//We can find button using button name or button id
for (AccessibilityNodeInfo node : list) {
node.performAction(AccessibilityNodeInfo.ACTION_CLICK);
}
list = nodeInfo
.findAccessibilityNodeInfosByViewId("android:id/button1");
for (AccessibilityNodeInfo node : list) {
node.performAction(AccessibilityNodeInfo.ACTION_CLICK);
}
}
}
#Override
public void onInterrupt() {
// TODO Auto-generated method stub
}
}
Open Setting screen click application which u want to force stop from installed application.
https://developer.android.com/guide/topics/ui/accessibility/services.html#event-details

Check whether Internet is on or off in Xamarin Android

I am working on Xamarin Android Application.Before proceed to my next fragment I want to check Internet Connection and inform user about it ? How can i implement that ?And how to refresh whole fragment after user switch-on the internet?
Any advice or suggestion will be appreciated !

To get the network status you could use the following method in your activity:
public bool IsOnline()
{
var cm = (ConnectivityManager)GetSystemService(ConnectivityService);
return cm.ActiveNetworkInfo == null ? false : cm.ActiveNetworkInfo.IsConnected;
}
If I understood you correctly from this sentence: And how to refresh whole fragment after user switch-on the internet, You want to detect, whenever any changes in the connection status happens, Therefore you absolutely need to use broadcast receivers.
First of all you should implement a broadcast receiver with a simple Event named ConnectionStatusChanged as follows:
[BroadcastReceiver()]
public class NetworkStatusBroadcastReceiver : BroadcastReceiver
{
public event EventHandler ConnectionStatusChanged;
public override void OnReceive(Context context, Intent intent)
{
if (ConnectionStatusChanged != null)
ConnectionStatusChanged(this, EventArgs.Empty);
}
}
Then in your activity (in OnCreate() method for example, It doesn't matter) create an instance of that receiver and register it:
var _broadcastReceiver = new NetworkStatusBroadcastReceiver();
_broadcastReceiver.ConnectionStatusChanged += OnNetworkStatusChanged;
Application.Context.RegisterReceiver(_broadcastReceiver,
new IntentFilter(ConnectivityManager.ConnectivityAction));
Here is the body of the event handler:
private void OnNetworkStatusChanged(object sender, EventArgs e)
{
if(IsOnline()){
Toast.MakeText(this, "Network Activated", ToastLength.Short).Show();
// refresh content fragment.
}
}
To cut the long story short, NetworkStatusBroadcastReceiver receives any change in the network status of the device and invokes the ConnectionStatusChanged (When user enables data traffic or WiFi connection), Then you catch that event and check for network status using IsOnline() method. Very simple.

You can use the MVVMCross plugin : Connectivity
It wil expose a boolean
/// <summary>
/// Gets if there is an active internet connection
/// </summary>
bool IsConnected { get; }
and a delegate on change state
/// <summary>
/// Event handler when connection changes
/// </summary>
event ConnectivityChangedEventHandler ConnectivityChanged;

Try this :
NetworkStatus internetStatus = Reachability.InternetConnectionStatus();
if(!Reachability.IsHostReachable("http://google.com")) {
// Put alternative content/message here
}
else
{
// Put Internet Required Code here
}